The emergence of mechanically one-way materials presents an exciting opportunity for materials science and engineering. These substances exhibit unique nonreciprocal mechanical responses, enabling them to selectively ...The emergence of mechanically one-way materials presents an exciting opportunity for materials science and engineering. These substances exhibit unique nonreciprocal mechanical responses, enabling them to selectively channel mechanical energy and facilitate directed sound propagation, controlled mass transport, and concentration of mechanical energy amidst random motion. This article explores the fundamentals of mechanically one-way materials, their potential applications across various industries, and the economic and environmental considerations related to their production and use.展开更多
We concentrate on the skin effects and topological properties in the multilayer non-Hermitian Su−Schrieffer−Heeger (SSH) structure, by taking into account the nonreciprocal couplings between the different sublattices ...We concentrate on the skin effects and topological properties in the multilayer non-Hermitian Su−Schrieffer−Heeger (SSH) structure, by taking into account the nonreciprocal couplings between the different sublattices in the unit cells. Following the detailed demonstration of the theoretical method, we find that in this system, the skin effects and topological phase transitions induced by nonreciprocal couplings display the apparent parity effect, following the increase of the layer number of this SSH structure. On the one hand, the skin effect is determined by the parity of the layer number of this SSH system, as well as the parity of the band index of the bulk states. On the other hand, for the topological edge modes, such an interesting parity effect can also be observed clearly. Next, when the parameter disorders are taken into account, the zero-energy edge modes in the odd-layer structures tend to be more robust, whereas the other edge modes are easy to be destroyed. In view of these results, it can be ascertained that the findings in this work promote to understand the influences of nonreciprocal couplings on the skin effects and topological properties in the multilayer SSH lattices.展开更多
A catadioptric lens structure,also known as pancake lens,has been widely used in virtual reality(VR)displays to reduce the formfactor.However,the utilization of a half mirror(HM)to fold the optical path thrice leads t...A catadioptric lens structure,also known as pancake lens,has been widely used in virtual reality(VR)displays to reduce the formfactor.However,the utilization of a half mirror(HM)to fold the optical path thrice leads to a significant optical loss.The theoretical maximum optical efficiency is merely 25%.To transcend this optical efficiency constraint while retaining the foldable characteristic inherent to traditional pancake optics,in this paper,we propose a theoretically lossless folded optical system to replace the HM with a nonreciprocal polarization rotator.In our feasibility demonstration experiment,we used a commercial Faraday rotator(FR)and reflective polarizers to replace the lossy HM.The theoretically predicted 100%efficiency can be achieved approximately by using two high-extinction-ratio reflective polarizers.In addition,we evaluated the ghost images using a micro-OLED panel in our imaging system.Indeed,the ghost images can be suppressed to undetectable level if the optics are with antireflection coating.Our novel pancake optical system holds great potential for revolutionizing next-generation VR displays with lightweight,compact formfactor,and low power consumption.展开更多
According to Kirchhoff's radiation law,the spectral-directional absorptivity(α)and spectral-directional emissivity(e)of an object are widely believed to be identical,which places a fundamental limit on photonic e...According to Kirchhoff's radiation law,the spectral-directional absorptivity(α)and spectral-directional emissivity(e)of an object are widely believed to be identical,which places a fundamental limit on photonic energy conversion and management.The introduction of Weyl semimetals and magneto-optical(MO)materials into photonic crystals makes it possible to violate Kirchhoff's law,but most existing work only report the unequal absorptivity and emissivity spectra in a single band,which cannot meet the requirements of most practical applications.Here,we introduce a defect layer into the structure composed of one-dimensional(1D)magnetophotonic crystal and a metal layer,which realizes dual-band nonreciprocal thermal radiation under a 3-T magnetic field with an incident angle of 60°.The realization of dual-band nonreciprocal radiation is mainly due to the Fabry-Perot(FP)resonance occurring in the defect layer and the excitation of Tamm plasmon,which is proved by calculating the magnetic field distribution.In addition,the effects of incident angle and structural parameters on nonreciprocity are also studied.What is more,the number of nonreciprocal bands could be further increased by tuning the defect layer thickness.When the defect layer thickness increases to 18.2μm,tri-band nonreciprocal thermal radiation is realized due to the enhanced number of defect modes in the photonic band gap and the FP resonance occurring in the defect layer.Finally,the effect of defect location on nonreciprocity is also discussed.The present work provides a new way for the design of multi-band or even broad-band nonreciprocal thermal emitters.展开更多
Due to the lack of inversion,mirror or other roto-inversion symmetries,chiral crystals possess a well-defined handedness which,when combined with time-reversal symmetry breaking from the application of magnetic fields...Due to the lack of inversion,mirror or other roto-inversion symmetries,chiral crystals possess a well-defined handedness which,when combined with time-reversal symmetry breaking from the application of magnetic fields,can give rise to directional dichroism of the electrical transport phenomena via the magnetochiral anisotropy.In this study,we investigate the nonreciprocal magneto-transport in microdevices of NbGe_(2),a superconductor with structural chirality.A giant nonreciprocal signal from vortex motions is observed during the superconducting transition,with the ratio of nonreciprocal resistance to the normal resistanceγreaching 6×10^(5)T^(-1)·A^(-1).Interestingly,the intensity can be adjusted and even sign-reversed by varying the current,the temperature,and the crystalline orientation.Our findings illustrate intricate vortex dynamics and offer ways of manipulation on the rectification effect in superconductors with structural chirality.展开更多
Phonon lasers or coherent amplifications of mechanical oscillations are powerful tools for fundamental studies on coherent acoustics and hold potential for diverse applications,ranging from ultrasensitive force sensin...Phonon lasers or coherent amplifications of mechanical oscillations are powerful tools for fundamental studies on coherent acoustics and hold potential for diverse applications,ranging from ultrasensitive force sensing to phononic information processing.Here,we propose the use of an optomechanical resonator coupled to a nonlinear optical resonator for directional phonon lasing.We find that by pumping the nonlinear optical resonator,directional optical squeezing can occur along the pump direction.As a result,we can achieve the directional mechanical gain using directional optical squeezing,thereby leading to nonreciprocal phonon lasing with a well-tunable directional power threshold.Our work proposes a feasible way to build nonreciprocal phonon lasers with various nonlinear optical media,which are important for a wide range of applications,such as directional acoustic amplifiers,invisible sound sensing or imaging,and one-way phononic networks.展开更多
We propose a scheme for realizing the optical nonreciprocal response based a four-mode optomechanical system,consisting of two charged mechanical modes and two linearly coupled optical modes. Two charged mechanical mo...We propose a scheme for realizing the optical nonreciprocal response based a four-mode optomechanical system,consisting of two charged mechanical modes and two linearly coupled optical modes. Two charged mechanical modes are coupled by Coulomb interaction, and two optical modes are coupled to one of mechanical modes by radiation pressure. We numerically evaluate the transmission probability of the probe field to obtain the optimum optical nonreciprocal response parameters. Also, we show that the optical nonreciprocal response is caused by the quantum interference between the optomechanical couplings and the linearly coupled interaction that breaks the time-reversal symmetry.展开更多
Nonreciprocal devices are indispensable for building quantum networks and ubiquitous in modern communication technology.Here, we study perfect optical nonreciprocity in a three-mode optomechanical system with mechanic...Nonreciprocal devices are indispensable for building quantum networks and ubiquitous in modern communication technology.Here, we study perfect optical nonreciprocity in a three-mode optomechanical system with mechanical driving.The scheme relies on the interference between optomechanical interaction and mechanical driving.We find perfect optical nonreciprocity can be achieved even though nonreciprocal phase difference is zero if we drive the system by a mechanical driving with a nonzero phase.We obtain the essential conditions for perfect optical nonreciprocity and analyze properties of the optical nonreciprocal transmission.These results can be used to control optical transmission in quantum information processing.展开更多
Nonreciprocal elements,such as isolators and circulators,play an important role in classical and quantum information processing.Recently,strong nonreciprocal effects have been experimentally demonstrated in cavity opt...Nonreciprocal elements,such as isolators and circulators,play an important role in classical and quantum information processing.Recently,strong nonreciprocal effects have been experimentally demonstrated in cavity optomechanical systems.In these approaches,the bandwidth of the nonreciprocal photon transmission is limited by the mechanical resonator linewidth,which is arguably much smaller than the linewidths of the cavity modes in most electromechanical or optomechanical devices.In this work,we demonstrate broadband nonreciprocal photon transmission in the reversed-dissipation regime,where the mechanical mode with a large decay rate can be adiabatically eliminated while mediating anti-PT-symmetric dissipative coupling with two kinds of phase factors.Adjusting the relative phases allows the observation of periodic Riemann-sheet structures with distributed exceptional points(Eps).At the Eps,destructive quantum interference breaks both theT-andP-inversion symmetry,resulting in unidirectional and chiral photon transmissions.In the reversed-dissipation regime,the nonreciprocal bandwidth is no longer limited by the mechanical mode linewidth but is improved to the linewidth of the cavity resonance.Furthermore,we find that the direction of the unidirectional and chiral energy transfer could be reversed by changing the parity of the Eps.Extending non-Hermitian couplings to a three-cavity model,the broken anti-PT-symmetry allows us to observe high-order Eps,at which a parity-dependent chiral circulator is demonstrated.The driving-phase controlled periodical Riemann sheets allow observation of the parity-dependent unidirectional and chiral energy transfer and thus provide a useful cell for building up nonreciprocal array and realizing topological,e.g.,isolators,circulators,or amplifiers.展开更多
We propose magnetized gyromagnetic photonic crystals(MGPCs)composed of indium antimonide(InSb)and yttrium iron garnet ferrite(YIGF)layers,which possess the properties of nonreciprocal wide-angle bidirectional absorpti...We propose magnetized gyromagnetic photonic crystals(MGPCs)composed of indium antimonide(InSb)and yttrium iron garnet ferrite(YIGF)layers,which possess the properties of nonreciprocal wide-angle bidirectional absorption.Periodical defects in the MGPCs work as filters.Absorption bands(ABs)for the positive and negative propagations arise from the optical Tamm state and resonance in cavities respectively,and they prove to share no overlaps in the studied frequency range.Givenω=2.0138 THz,for the positive propagation,the ABs in the high-frequency range are localized in the interval between 0.66ωand 0.88ω.In the angular range,the ABs for the TE and TM waves reach 60°and 51°,separately.For the negative propagation,the ABs in the low-frequency range are localized in the interval between 0.13ωand 0.3ω.The AB s extend to 60°for the TE waves and 80.4°for the TM waves.There also exists a narrow frequency band in a lower frequency range.The relevant factors,which include the external temperature,the magnetic fields applied to the YIGF,the refractive index of the impedance matching layer,and the defect thickness,are adjusted to investigate the effects on the ABs.All the numerical simulations are based on the transfer matrix method.This work provides an approach to designs of isolators and so on.展开更多
Using an improved particle swarm optimization algorithm(IPSO)to drive a transfer matrix method,a nonreciprocal absorber with an ultrawide absorption bandwidth and angular insensitivity is realized in plasma-embedded p...Using an improved particle swarm optimization algorithm(IPSO)to drive a transfer matrix method,a nonreciprocal absorber with an ultrawide absorption bandwidth and angular insensitivity is realized in plasma-embedded photonic crystals arranged in a structure composed of periodic and quasi-periodic sequences on a normalized scale.The effective dielectric function,which determines the absorption of the plasma,is subject to the basic parameters of the plasma,causing the absorption of the proposed absorber to be easily modulated by these parameters.Compared with other quasi-periodic sequences,the Octonacci sequence is superior both in relative bandwidth and absolute bandwidth.Under further optimization using IPSO with 14 parameters set to be optimized,the absorption characteristics of the proposed structure with different numbers of layers of the smallest structure unit N are shown and discussed.IPSO is also used to address angular insensitive nonreciprocal ultrawide bandwidth absorption,and the optimized result shows excellent unidirectional absorbability and angular insensitivity of the proposed structure.The impacts of the sequence number of quasi-periodic sequence M and collision frequency of plasma1ν1 to absorption in the angle domain and frequency domain are investigated.Additionally,the impedance match theory and the interference field theory are introduced to express the findings of the algorithm.展开更多
Nonreciprocal devices are indispen.sablo for building quantuin networks and ubiquitous in modern communication technology.Here,we propose to take advantage of the interference between optome-chanical interaction and l...Nonreciprocal devices are indispen.sablo for building quantuin networks and ubiquitous in modern communication technology.Here,we propose to take advantage of the interference between optome-chanical interaction and lincarly-couplcd interaction to realize optical nonreciprocal transmission in a double-cavity optomechanical system.Particularly,we have derived essential conditions for perfect optical nonrcciprocity ancl analysed properties of the optical nonreciprocal transmission.These results can be used to control optical transmission in quantum information processing.展开更多
We investigate the single-photon scattering properties of a driven three-level giant atom chirally coupled to two waveguides simultaneously in both the Markovian and the non-Markovian regimes.It is shown that under th...We investigate the single-photon scattering properties of a driven three-level giant atom chirally coupled to two waveguides simultaneously in both the Markovian and the non-Markovian regimes.It is shown that under the Markovian limit,the chiral photon-atom interactions enable nonreciprocal scattering in a single waveguide and targeted photon routing with a probability of 100%in two waveguides,while the presence of the driving field and the giant atom structure introduce a more tunable parameter to manipulate the single-photon scattering behaviors.We also examine how the non-reciprocity and routing capability are influenced by the imperfect chirality and the atomic dissipation.In the non-Markovian regime,we show that the scattering behaviors are more complicated.The non-Markovicity induced non-reciprocity and photon routing are demonstrated in this paper.We believe that those results have potential applications in quantum network engineering.展开更多
Nonreciprocal interlayer coupling is difcult to practically implement in bilayer non-Hermitian topological photonic systems.In this work,we identify a similarity transformation between the Hamiltonians of systems with...Nonreciprocal interlayer coupling is difcult to practically implement in bilayer non-Hermitian topological photonic systems.In this work,we identify a similarity transformation between the Hamiltonians of systems with nonreciprocal interlayer coupling and on-site gain/loss.The similarity transformation is widely applicable,and we show its application in one-and two-dimensional bilayer topological systems as examples.The bilayer non-Hermitian system with nonreciprocal interlayer coupling,whose topological number can be defned using the gauge-smoothed Wilson loop,is topologically equivalent to the bilayer system with on-site gain/loss.We also show that the topological number of bilayer non-Hermitian C6v-typed domaininduced topological interface states can be defned in the same way as in the case of the bilayer non-Hermitian Su–Schrieffer–Heeger model.Our results show the relations between two microscopic provenances of the non-Hermiticity and provide a universal and convenient scheme for constructing and studying nonreciprocal interlayer coupling in bilayer non-Hermitian topological systems.This scheme is useful for observation of non-Hermitian skin efect in three-dimensional systems.展开更多
Nonreciprocal microwave devices,in which the transmission of waves is non-symmetric between two ports,are indispensable for the manipulation of information processing and communication.In this work,we show the nonreci...Nonreciprocal microwave devices,in which the transmission of waves is non-symmetric between two ports,are indispensable for the manipulation of information processing and communication.In this work,we show the nonreciprocal microwave transmission in a cavity magnonic system under the joint mechanism of phase modulation and magnon Kerr nonlinearity effect.In contrast to the schemes based on the standard phase modulation or magnon Kerr nonlinearity,we find that the joint mechanism enables the nonreciprocal transmission even at low power and makes us obtain a high nonreciprocal isolation ratio.Moreover,when two microwave modes are coupled to the magnon mode via a different coupling strength,the presented strong nonreciprocal response occurs,and it makes the nonreciprocal transmission manipulating by the magnetic field within a large adjustable range possible,which overcomes narrow operating bandwidths.This study may provide promising opportunities to realize nonreciprocal structures for wave transmission.展开更多
Chiral quantum optics is a new research area in light-matter interaction that depends on the direction of light propagation and offers a new path for the quantum regulation of light-matter interactions.In this paper,w...Chiral quantum optics is a new research area in light-matter interaction that depends on the direction of light propagation and offers a new path for the quantum regulation of light-matter interactions.In this paper,we study a spinning Kerr-type microresonator coupled withΛ-type atom ensembles,which are driven in opposite directions to generate asymmetric photon statistics.We find that a photon blockade can only be generated by driving the spinning resonator on right side without driving the spinning microresonator from the left side,resulting in chirality.The coupling strength between system modes can be precisely controlled by adjusting the detuning amount of the atomic pump field.Because of the splitting of the resonant frequency generated by the Fizeau drag,the destructive quantum interference generated in right side drive prevents the nonresonant transition path of state|1,0⟩to state|2,0⟩.This direction-dependent chiral quantum optics is expected to be applied to chiral optical devices,single-photon sources and nonreciprocal quantum communications.展开更多
We study the nonreciprocal properties of transmitted photons in a chiral waveguide quantum electrodynamics(QED)system,including single-and two-photon transmissions and second-order correlations.For the single-photon t...We study the nonreciprocal properties of transmitted photons in a chiral waveguide quantum electrodynamics(QED)system,including single-and two-photon transmissions and second-order correlations.For the single-photon transmission,the nonreciprocity is induced by the effects of chiral coupling and atomic dissipation in the weak coupling region.It vanishes in the strong coupling regime when the effect of atomic dissipation becomes ignorable.In the case of two-photon transmission,there exist two ways of going through the emitter:independently as plane waves and formation of bound state.Besides the nonreciprocal behavior of plane waves,the bound state that differs in two directions also alters transmission probabilities.In addition,the second-order correlation of transmitted photons depends on the interference between plane wave and bound state.The destructive interference leads to the strong antibunching in the weak coupling region,while the effective formation of bound state leads to the strong bunching in the intermediate coupling region.However,the negligible interactions for left-propagating photons hardly change the statistics of the input coherent state.展开更多
The generalized principle of least action in electromagnetism is presented, which is effective even though in lossy and nonreciprocal media. It is pointed out that the Maxwell’s equations can be derived from this pri...The generalized principle of least action in electromagnetism is presented, which is effective even though in lossy and nonreciprocal media. It is pointed out that the Maxwell’s equations can be derived from this principle. At last for example of its applications, some useful variational expressions for electromagnetic fields are derived systematically from the principle.展开更多
Twisted bilayer graphene(TBG)exhibits fascinating correlation-driven phenomena like the superconductivity and Mott insulating state,with flat bands and a chiral lattice structure.We find by quantum-transport calculati...Twisted bilayer graphene(TBG)exhibits fascinating correlation-driven phenomena like the superconductivity and Mott insulating state,with flat bands and a chiral lattice structure.We find by quantum-transport calculations that the chirality leads to a giant unidirectional magnetoresistance(UMR)in TBG,where the unidirectionality refers to the resistance change under the reversal of the direction of current or magnetic field.We point out that flat bands significantly enhance this effect.The UMR increases quickly upon reducing the twist angle,and reaches about 20%for an angle of 1.5in a 10 T in-plane magnetic field.We propose the band structure topology(asymmetry),which leads to a direction-sensitive mean free path,as a useful way to anticipate the UMR effect.The UMR provides a probe for chirality and band flatness in the twisted bilayers.展开更多
文摘The emergence of mechanically one-way materials presents an exciting opportunity for materials science and engineering. These substances exhibit unique nonreciprocal mechanical responses, enabling them to selectively channel mechanical energy and facilitate directed sound propagation, controlled mass transport, and concentration of mechanical energy amidst random motion. This article explores the fundamentals of mechanically one-way materials, their potential applications across various industries, and the economic and environmental considerations related to their production and use.
基金the LiaoNing Revitalization Talents Program(Grant No.XLYC1907033)the National Natural Science Foundation of China(Grant No.11905027)+1 种基金the Natural Science Foundation of Liaoning province(Grant No.2023-MS-072)Fundamental Research Funds for the Central Universities of Ministry of Education of China(Grant Nos.N2209005 and N2205015).
文摘We concentrate on the skin effects and topological properties in the multilayer non-Hermitian Su−Schrieffer−Heeger (SSH) structure, by taking into account the nonreciprocal couplings between the different sublattices in the unit cells. Following the detailed demonstration of the theoretical method, we find that in this system, the skin effects and topological phase transitions induced by nonreciprocal couplings display the apparent parity effect, following the increase of the layer number of this SSH structure. On the one hand, the skin effect is determined by the parity of the layer number of this SSH system, as well as the parity of the band index of the bulk states. On the other hand, for the topological edge modes, such an interesting parity effect can also be observed clearly. Next, when the parameter disorders are taken into account, the zero-energy edge modes in the odd-layer structures tend to be more robust, whereas the other edge modes are easy to be destroyed. In view of these results, it can be ascertained that the findings in this work promote to understand the influences of nonreciprocal couplings on the skin effects and topological properties in the multilayer SSH lattices.
文摘A catadioptric lens structure,also known as pancake lens,has been widely used in virtual reality(VR)displays to reduce the formfactor.However,the utilization of a half mirror(HM)to fold the optical path thrice leads to a significant optical loss.The theoretical maximum optical efficiency is merely 25%.To transcend this optical efficiency constraint while retaining the foldable characteristic inherent to traditional pancake optics,in this paper,we propose a theoretically lossless folded optical system to replace the HM with a nonreciprocal polarization rotator.In our feasibility demonstration experiment,we used a commercial Faraday rotator(FR)and reflective polarizers to replace the lossy HM.The theoretically predicted 100%efficiency can be achieved approximately by using two high-extinction-ratio reflective polarizers.In addition,we evaluated the ghost images using a micro-OLED panel in our imaging system.Indeed,the ghost images can be suppressed to undetectable level if the optics are with antireflection coating.Our novel pancake optical system holds great potential for revolutionizing next-generation VR displays with lightweight,compact formfactor,and low power consumption.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.52211540005,52076087)the Open Project Program of Wuhan National Laboratory for Optoelectronics(Grant No.2021WNLOKF004)+1 种基金Wuhan Knowledge Innovation Shuguang Programthe Science and Technology Program of Hubei Province(Grant No.2021BLB176)。
文摘According to Kirchhoff's radiation law,the spectral-directional absorptivity(α)and spectral-directional emissivity(e)of an object are widely believed to be identical,which places a fundamental limit on photonic energy conversion and management.The introduction of Weyl semimetals and magneto-optical(MO)materials into photonic crystals makes it possible to violate Kirchhoff's law,but most existing work only report the unequal absorptivity and emissivity spectra in a single band,which cannot meet the requirements of most practical applications.Here,we introduce a defect layer into the structure composed of one-dimensional(1D)magnetophotonic crystal and a metal layer,which realizes dual-band nonreciprocal thermal radiation under a 3-T magnetic field with an incident angle of 60°.The realization of dual-band nonreciprocal radiation is mainly due to the Fabry-Perot(FP)resonance occurring in the defect layer and the excitation of Tamm plasmon,which is proved by calculating the magnetic field distribution.In addition,the effects of incident angle and structural parameters on nonreciprocity are also studied.What is more,the number of nonreciprocal bands could be further increased by tuning the defect layer thickness.When the defect layer thickness increases to 18.2μm,tri-band nonreciprocal thermal radiation is realized due to the enhanced number of defect modes in the photonic band gap and the FP resonance occurring in the defect layer.Finally,the effect of defect location on nonreciprocity is also discussed.The present work provides a new way for the design of multi-band or even broad-band nonreciprocal thermal emitters.
基金Project supported by the National Key R&D Program of China(Grant No.2022YFA1403603)the National Natural Science Foundation of China(Grant Nos.U2032213,12104461,12374129,and 12304156)+1 种基金Chinese Academy of Sciences(Grant Nos.YSBR-084,and JZHKYPT-2021-08)A portion of this work was supported by the High Magnetic Field Laboratory of Anhui Province.
文摘Due to the lack of inversion,mirror or other roto-inversion symmetries,chiral crystals possess a well-defined handedness which,when combined with time-reversal symmetry breaking from the application of magnetic fields,can give rise to directional dichroism of the electrical transport phenomena via the magnetochiral anisotropy.In this study,we investigate the nonreciprocal magneto-transport in microdevices of NbGe_(2),a superconductor with structural chirality.A giant nonreciprocal signal from vortex motions is observed during the superconducting transition,with the ratio of nonreciprocal resistance to the normal resistanceγreaching 6×10^(5)T^(-1)·A^(-1).Interestingly,the intensity can be adjusted and even sign-reversed by varying the current,the temperature,and the crystalline orientation.Our findings illustrate intricate vortex dynamics and offer ways of manipulation on the rectification effect in superconductors with structural chirality.
基金supported by the National Natural Science Foundation of China(Grant No.11935006)the Hunan Provincial Major Sci-Tech Program(Grant No.2023ZJ1010)+10 种基金the Science and Technology Innovation Program of Hunan Province(Grant No.2020RC4047)supported by the National Natural Science Foundation of China(Grant Nos.12247105,12175060,and 11935006)XJ-Lab Key Project(Grant No.23XJ02001).Keyu Xia was supported by the National Key R&D Program of China(Grant No.2019YFA0308704)the National Natural Science Foundation of China(Grant No.92365107)the Program for Innovative Talents and Teams in Jiangsu(Grant No.JSSCTD202138)supported by the National Natural Science Foundation of China(Grant No.12205054)the Jiangxi Provincial Education Office Natural Science Fund Project(Grant No.GJJ211437)the Ph.D.Research Foundation(Grant No.BSJJ202122)supported by the National Natural Science Foundation of China(Grant No.12265004)supported by the National Natural Science Foundation of China(Grant No.12205256)the Henan Provincial Science and Technology Research Project(GrantNo.232102221001)。
文摘Phonon lasers or coherent amplifications of mechanical oscillations are powerful tools for fundamental studies on coherent acoustics and hold potential for diverse applications,ranging from ultrasensitive force sensing to phononic information processing.Here,we propose the use of an optomechanical resonator coupled to a nonlinear optical resonator for directional phonon lasing.We find that by pumping the nonlinear optical resonator,directional optical squeezing can occur along the pump direction.As a result,we can achieve the directional mechanical gain using directional optical squeezing,thereby leading to nonreciprocal phonon lasing with a well-tunable directional power threshold.Our work proposes a feasible way to build nonreciprocal phonon lasers with various nonlinear optical media,which are important for a wide range of applications,such as directional acoustic amplifiers,invisible sound sensing or imaging,and one-way phononic networks.
文摘We propose a scheme for realizing the optical nonreciprocal response based a four-mode optomechanical system,consisting of two charged mechanical modes and two linearly coupled optical modes. Two charged mechanical modes are coupled by Coulomb interaction, and two optical modes are coupled to one of mechanical modes by radiation pressure. We numerically evaluate the transmission probability of the probe field to obtain the optimum optical nonreciprocal response parameters. Also, we show that the optical nonreciprocal response is caused by the quantum interference between the optomechanical couplings and the linearly coupled interaction that breaks the time-reversal symmetry.
基金Supported by the National Natural Science Foundation of China under Grant Nos.41472126,11847018Natural Science Foundation of Guangxi Province under Grant No.2018GXNSFBA281003+1 种基金Starting Research Fund from the Guangxi Normal University(2017BQ022)Northeast Petroleum University Youth Foundation(NEPUQN2015–1–16)
文摘Nonreciprocal devices are indispensable for building quantum networks and ubiquitous in modern communication technology.Here, we study perfect optical nonreciprocity in a three-mode optomechanical system with mechanical driving.The scheme relies on the interference between optomechanical interaction and mechanical driving.We find perfect optical nonreciprocity can be achieved even though nonreciprocal phase difference is zero if we drive the system by a mechanical driving with a nonzero phase.We obtain the essential conditions for perfect optical nonreciprocity and analyze properties of the optical nonreciprocal transmission.These results can be used to control optical transmission in quantum information processing.
基金supported by the China Postdoctoral Science Foundation under Grant No.2021M700442Y.L.Liu acknowledges the support of the Natural Science Foundation of China(NSFC)under Grant No.12004044+5 种基金H.F.Y acknowledges the support from the NSFC of China(11890704)the NSF of Beijing(Z190012)T.F.Li acknowledges the support of the Development Program of China(2016YFA0301200)the National Natural Science Foundation of China(62074091,and U1930402)the Science Challenge Project(TZ2018003)Tsinghua University Initiative Scientific Research Program.
文摘Nonreciprocal elements,such as isolators and circulators,play an important role in classical and quantum information processing.Recently,strong nonreciprocal effects have been experimentally demonstrated in cavity optomechanical systems.In these approaches,the bandwidth of the nonreciprocal photon transmission is limited by the mechanical resonator linewidth,which is arguably much smaller than the linewidths of the cavity modes in most electromechanical or optomechanical devices.In this work,we demonstrate broadband nonreciprocal photon transmission in the reversed-dissipation regime,where the mechanical mode with a large decay rate can be adiabatically eliminated while mediating anti-PT-symmetric dissipative coupling with two kinds of phase factors.Adjusting the relative phases allows the observation of periodic Riemann-sheet structures with distributed exceptional points(Eps).At the Eps,destructive quantum interference breaks both theT-andP-inversion symmetry,resulting in unidirectional and chiral photon transmissions.In the reversed-dissipation regime,the nonreciprocal bandwidth is no longer limited by the mechanical mode linewidth but is improved to the linewidth of the cavity resonance.Furthermore,we find that the direction of the unidirectional and chiral energy transfer could be reversed by changing the parity of the Eps.Extending non-Hermitian couplings to a three-cavity model,the broken anti-PT-symmetry allows us to observe high-order Eps,at which a parity-dependent chiral circulator is demonstrated.The driving-phase controlled periodical Riemann sheets allow observation of the parity-dependent unidirectional and chiral energy transfer and thus provide a useful cell for building up nonreciprocal array and realizing topological,e.g.,isolators,circulators,or amplifiers.
基金Project supported by the College Student Innovation Training Program of Nanjing University of Posts and Telecommunicationsthe Jiangsu Agriculture Science and Technology Innovation Fund(JASTIF)(Grant No.CX(21)3187)。
文摘We propose magnetized gyromagnetic photonic crystals(MGPCs)composed of indium antimonide(InSb)and yttrium iron garnet ferrite(YIGF)layers,which possess the properties of nonreciprocal wide-angle bidirectional absorption.Periodical defects in the MGPCs work as filters.Absorption bands(ABs)for the positive and negative propagations arise from the optical Tamm state and resonance in cavities respectively,and they prove to share no overlaps in the studied frequency range.Givenω=2.0138 THz,for the positive propagation,the ABs in the high-frequency range are localized in the interval between 0.66ωand 0.88ω.In the angular range,the ABs for the TE and TM waves reach 60°and 51°,separately.For the negative propagation,the ABs in the low-frequency range are localized in the interval between 0.13ωand 0.3ω.The AB s extend to 60°for the TE waves and 80.4°for the TM waves.There also exists a narrow frequency band in a lower frequency range.The relevant factors,which include the external temperature,the magnetic fields applied to the YIGF,the refractive index of the impedance matching layer,and the defect thickness,are adjusted to investigate the effects on the ABs.All the numerical simulations are based on the transfer matrix method.This work provides an approach to designs of isolators and so on.
文摘Using an improved particle swarm optimization algorithm(IPSO)to drive a transfer matrix method,a nonreciprocal absorber with an ultrawide absorption bandwidth and angular insensitivity is realized in plasma-embedded photonic crystals arranged in a structure composed of periodic and quasi-periodic sequences on a normalized scale.The effective dielectric function,which determines the absorption of the plasma,is subject to the basic parameters of the plasma,causing the absorption of the proposed absorber to be easily modulated by these parameters.Compared with other quasi-periodic sequences,the Octonacci sequence is superior both in relative bandwidth and absolute bandwidth.Under further optimization using IPSO with 14 parameters set to be optimized,the absorption characteristics of the proposed structure with different numbers of layers of the smallest structure unit N are shown and discussed.IPSO is also used to address angular insensitive nonreciprocal ultrawide bandwidth absorption,and the optimized result shows excellent unidirectional absorbability and angular insensitivity of the proposed structure.The impacts of the sequence number of quasi-periodic sequence M and collision frequency of plasma1ν1 to absorption in the angle domain and frequency domain are investigated.Additionally,the impedance match theory and the interference field theory are introduced to express the findings of the algorithm.
基金L. Yang was supported by the National Natural Science Foundation of China (Grant No. 11804066)the China Postdoctoral Science Foundation (Grant No. 2018M630337)Fundamental Research Funds for the Central Universities (Grant No. 3072019CFM0405).
文摘Nonreciprocal devices are indispen.sablo for building quantuin networks and ubiquitous in modern communication technology.Here,we propose to take advantage of the interference between optome-chanical interaction and lincarly-couplcd interaction to realize optical nonreciprocal transmission in a double-cavity optomechanical system.Particularly,we have derived essential conditions for perfect optical nonrcciprocity ancl analysed properties of the optical nonreciprocal transmission.These results can be used to control optical transmission in quantum information processing.
文摘We investigate the single-photon scattering properties of a driven three-level giant atom chirally coupled to two waveguides simultaneously in both the Markovian and the non-Markovian regimes.It is shown that under the Markovian limit,the chiral photon-atom interactions enable nonreciprocal scattering in a single waveguide and targeted photon routing with a probability of 100%in two waveguides,while the presence of the driving field and the giant atom structure introduce a more tunable parameter to manipulate the single-photon scattering behaviors.We also examine how the non-reciprocity and routing capability are influenced by the imperfect chirality and the atomic dissipation.In the non-Markovian regime,we show that the scattering behaviors are more complicated.The non-Markovicity induced non-reciprocity and photon routing are demonstrated in this paper.We believe that those results have potential applications in quantum network engineering.
基金supported by the National Natural Science Foundation of China(Nos.91950204,92150302,and 62175009)Innovation Program for Quantum Science and Technology(No.2021ZD0301500)Open Research Fund Program of the State Key Laboratory of Low-Dimensional Quantum Physics(No.KF202114).
文摘Nonreciprocal interlayer coupling is difcult to practically implement in bilayer non-Hermitian topological photonic systems.In this work,we identify a similarity transformation between the Hamiltonians of systems with nonreciprocal interlayer coupling and on-site gain/loss.The similarity transformation is widely applicable,and we show its application in one-and two-dimensional bilayer topological systems as examples.The bilayer non-Hermitian system with nonreciprocal interlayer coupling,whose topological number can be defned using the gauge-smoothed Wilson loop,is topologically equivalent to the bilayer system with on-site gain/loss.We also show that the topological number of bilayer non-Hermitian C6v-typed domaininduced topological interface states can be defned in the same way as in the case of the bilayer non-Hermitian Su–Schrieffer–Heeger model.Our results show the relations between two microscopic provenances of the non-Hermiticity and provide a universal and convenient scheme for constructing and studying nonreciprocal interlayer coupling in bilayer non-Hermitian topological systems.This scheme is useful for observation of non-Hermitian skin efect in three-dimensional systems.
基金the National Natural Science Foundation of China(Grant Nos.12105092 and 12022507)Program for Innovative Teams of Outstanding Young and Middle-aged Researchers in the Higher Education Institution of Hubei Province(No.T2020014).
文摘Nonreciprocal microwave devices,in which the transmission of waves is non-symmetric between two ports,are indispensable for the manipulation of information processing and communication.In this work,we show the nonreciprocal microwave transmission in a cavity magnonic system under the joint mechanism of phase modulation and magnon Kerr nonlinearity effect.In contrast to the schemes based on the standard phase modulation or magnon Kerr nonlinearity,we find that the joint mechanism enables the nonreciprocal transmission even at low power and makes us obtain a high nonreciprocal isolation ratio.Moreover,when two microwave modes are coupled to the magnon mode via a different coupling strength,the presented strong nonreciprocal response occurs,and it makes the nonreciprocal transmission manipulating by the magnetic field within a large adjustable range possible,which overcomes narrow operating bandwidths.This study may provide promising opportunities to realize nonreciprocal structures for wave transmission.
基金the support from the National Natural Science Foundation of China under Grant Nos.62071064 and 62131002the Fundamental Research Funds for the Central Universities of China under Grant No.2019XD-A02the Fund of State Key Laboratory of Information Photonics and Optical Communications(Beijing University of Posts and Telecommunications)(No.IPOC2022ZT10),China.
文摘Chiral quantum optics is a new research area in light-matter interaction that depends on the direction of light propagation and offers a new path for the quantum regulation of light-matter interactions.In this paper,we study a spinning Kerr-type microresonator coupled withΛ-type atom ensembles,which are driven in opposite directions to generate asymmetric photon statistics.We find that a photon blockade can only be generated by driving the spinning resonator on right side without driving the spinning microresonator from the left side,resulting in chirality.The coupling strength between system modes can be precisely controlled by adjusting the detuning amount of the atomic pump field.Because of the splitting of the resonant frequency generated by the Fizeau drag,the destructive quantum interference generated in right side drive prevents the nonresonant transition path of state|1,0⟩to state|2,0⟩.This direction-dependent chiral quantum optics is expected to be applied to chiral optical devices,single-photon sources and nonreciprocal quantum communications.
基金supported by the National Natural Science Foundation of China(Grant No.11704045)。
文摘We study the nonreciprocal properties of transmitted photons in a chiral waveguide quantum electrodynamics(QED)system,including single-and two-photon transmissions and second-order correlations.For the single-photon transmission,the nonreciprocity is induced by the effects of chiral coupling and atomic dissipation in the weak coupling region.It vanishes in the strong coupling regime when the effect of atomic dissipation becomes ignorable.In the case of two-photon transmission,there exist two ways of going through the emitter:independently as plane waves and formation of bound state.Besides the nonreciprocal behavior of plane waves,the bound state that differs in two directions also alters transmission probabilities.In addition,the second-order correlation of transmitted photons depends on the interference between plane wave and bound state.The destructive interference leads to the strong antibunching in the weak coupling region,while the effective formation of bound state leads to the strong bunching in the intermediate coupling region.However,the negligible interactions for left-propagating photons hardly change the statistics of the input coherent state.
文摘The generalized principle of least action in electromagnetism is presented, which is effective even though in lossy and nonreciprocal media. It is pointed out that the Maxwell’s equations can be derived from this principle. At last for example of its applications, some useful variational expressions for electromagnetic fields are derived systematically from the principle.
基金We thank the inspiring discussions with Yuval Oreg,Jiewen Xiao,Shahal Ilani,and Eli Zeldov.B.Y.acknowledges the financial support by the Willner Family Leadership Institute for the Weizmann Institute of Science,the Benoziyo Endowment Fund for the Advancement of Science,Ruth and Herman Albert Scholars Program for New Scientists,the European Research Council(ERC Consolidator Grant No.815869,“NonlinearTopo”).
文摘Twisted bilayer graphene(TBG)exhibits fascinating correlation-driven phenomena like the superconductivity and Mott insulating state,with flat bands and a chiral lattice structure.We find by quantum-transport calculations that the chirality leads to a giant unidirectional magnetoresistance(UMR)in TBG,where the unidirectionality refers to the resistance change under the reversal of the direction of current or magnetic field.We point out that flat bands significantly enhance this effect.The UMR increases quickly upon reducing the twist angle,and reaches about 20%for an angle of 1.5in a 10 T in-plane magnetic field.We propose the band structure topology(asymmetry),which leads to a direction-sensitive mean free path,as a useful way to anticipate the UMR effect.The UMR provides a probe for chirality and band flatness in the twisted bilayers.
