Quantum information is vulnerable to environmental noise and experimental imperfections,hindering the reli-ability of practical quantum information processors.Therefore,quantum error correction(QEC)that can pro-tect q...Quantum information is vulnerable to environmental noise and experimental imperfections,hindering the reli-ability of practical quantum information processors.Therefore,quantum error correction(QEC)that can pro-tect quantum information against noise is vital for universal and scalable quantum computation.Among many different experimental platforms,superconducting quantum circuits and bosonic encodings in superconducting microwave modes are appealing for their unprecedented potential in QEC.During the last few years,bosonic QEC is demonstrated to reach the break-even point,i.e.the lifetime of a logical qubit is enhanced to exceed that of any individual components composing the experimental system.Beyond that,universal gate sets and fault-tolerant operations on the bosonic codes are also realized,pushing quantum information processing towards the QEC era.In this article,we review the recent progress of the bosonic codes,including the Gottesman-Kitaev-Preskill codes,cat codes,and binomial codes,and discuss the opportunities of bosonic codes in various quantum applications,ranging from fault-tolerant quantum computation to quantum metrology.We also summarize the challenges associated with the bosonic codes and provide an outlook for the potential research directions in the long terms.展开更多
This report adds three protonic semiconductor models to explain the "abnormally" high electrical conductivity of pure liquid water characterized by the three industrial consensus parameters, the ion product(...This report adds three protonic semiconductor models to explain the "abnormally" high electrical conductivity of pure liquid water characterized by the three industrial consensus parameters, the ion product(or pH)and the two ion mobilities. Existence of long-range order in fluid water under numerous daily conditions led us to extend the 1933 Bernal-Fowler hexagonally close packed crystalline Ice Lattice to model liquid water as Melted Ice. Protonic kinetic energy band and bound(trap) pictures provide semiconductor-physics based new models of these three parameters. They are extrapolatable engineered-models for developing novel biological, chemical, electrical, mechanical and medical applications of liquid water.展开更多
In this paper we consider a model in which the masses of elementary particles are formed and stabilized thanks to confining potential, which is caused by recoil momentum at emission of specific virtual bosons by parti...In this paper we consider a model in which the masses of elementary particles are formed and stabilized thanks to confining potential, which is caused by recoil momentum at emission of specific virtual bosons by particle itself. The calculation of this confining potential Ф(R) is carried out. It is shown that Ф(R) may be in the form const or const depending on continuous or discrete nature of the spectrum of emitted bosons.展开更多
The interacting comma 3-vertex for the bosonic open string in the full string basis is derived using the half string overlap relations directly. Thus avoiding the coherent states technique employed in earlier derivati...The interacting comma 3-vertex for the bosonic open string in the full string basis is derived using the half string overlap relations directly. Thus avoiding the coherent states technique employed in earlier derivations. The resulting form of the interacting 3-vertex turns out to be precisely the desired expression obtained in terms of the full string oscillator modes. This derivation establishes that the comma 3-vertex and Witten’s 3-vertex are identical and therefore are interchangeable.展开更多
We construct a class of modules for the twisted multi-loop algebra of type A1 × A1 by applying Wakimoto free bosonic realization. We also discuss the structures and the irreducibility of the Fock space.
The fermionic and bosonic zero modes of the one-dimensional（1D） interacting Kitaev chain at the symmetric point are unveiled. The many-body structures of the Majorana zero modes in the topological region are given e...The fermionic and bosonic zero modes of the one-dimensional（1D） interacting Kitaev chain at the symmetric point are unveiled. The many-body structures of the Majorana zero modes in the topological region are given explicitly by carrying out a perturbation expansion up to infinite order. We also give the analytic expressions of the bosonic zero modes in the topologically trivial phase. Our results are generalized to the hybrid fermion system comprised of the interacting Kitaev model and the Su–Schrieffer–Heeger（SSH） model, in which we show that these two types of zero modes can coexist in a certain region of its phase diagram.展开更多
We consider the quantum mechanical SU（2） transformation e^2λJzJ±e^-2λJz = e^±2λJ±as if the meaning of squeezing with e^±2λ being squeezing parameter. By studying SU（2） operators （J±,...We consider the quantum mechanical SU（2） transformation e^2λJzJ±e^-2λJz = e^±2λJ±as if the meaning of squeezing with e^±2λ being squeezing parameter. By studying SU（2） operators （J±, Jz） from the point of view of squeezing we find that （J±,Jz） can also be realized in terms of 3-mode bosonic operators. Employing this realization, we find the natural representation （the eigenvectors of J＋ or J-） of the 3-mode squeezing operator e^2λJz. The idea of considering quantum SU（2） transformation as if squeezing is liable for us to obtain the new bosonic operator realization of SU（2） and new squeezing operators.展开更多
We conjecture the existence of massless neutrinos that are in the line of Standard Model (unable to account for the neutrino mass) but have characteristics that are not accounted for the Standard Model: they use a sho...We conjecture the existence of massless neutrinos that are in the line of Standard Model (unable to account for the neutrino mass) but have characteristics that are not accounted for the Standard Model: they use a shorter radial path than the photon and possess bosonic flavors, considered like bosons instead of fermions. We call this theory “neutrino temporal oscillation”. Faced with some experimental comparisons solar neutrinos, neutrinos from SN 1987A, cosmological neutrinos, the theory gives better results, explanations and sense than the complicated theory of neutrino oscillations (transformism). The deficit of detection of solar neutrinos would have been blindly attributed to the “neutrino oscillation” by physicists who quickly concluded that the neutrino and the photon follow the same transverse path. The “OPERA” experiment which measured the speed of neutrinos in 2011 resulted, after a “superluminal” saga, in neutrino speeds consistent with the speed of light, in data that the three existing types of neutrinos cannot explain, with the final outcome of a fourth “sterile” neutrino with non-standard interaction. OPERA findings aren’t just in conflict with existing theory, but other measurements as well. For example, a study from the Kamiokande II experiment in Japan of the supernova SN1987A found that light and neutrinos that departed this exploded star arrived at Earth within hours of each other. Even though measurements of the neutrinos emitted by this supernova strongly suggest that their speeds differ from light by less than one part in a billion, the fact remains that two types of data were collected, and that only one was retained to be consistent with the existing theory. Thus, the OPERA observation is in conflicts with the result of SN1987A, which itself is highly doubtful. And what about the neutrinos and antineutrinos born during the big bang, except that they were never detected and there is nothing to indicate that their speed could be other than that of light. Neutrino physi展开更多
It is in general accepted that the concept of continuous trajectories for particles is at odds with the relativistic quantum mechanics. Namely, when examining the evolution of entangled quantum objects according to fr...It is in general accepted that the concept of continuous trajectories for particles is at odds with the relativistic quantum mechanics. Namely, when examining the evolution of entangled quantum objects according to frames of coordinates in relative move-ment, one gets contradictory trajectories. Such a situation is typically derived from the famous “Hardy’s paradox”. However, it is argued here that if the rationale ignores the principle of quantum contextuality, as happens typically when using Hardy’s thought-experiment, the conclusion—rejection of the assumption of trajectories—is questionable. The issue is exemplified by an additional example: the 101 property of spin 1 bosons implies conflicting trajectories when the singlet state of two such bosons is examined according to frames in relative movement. It is concluded here that in the absence of a rationale which doesn’t violate the quantum contextuality, there are no sufficient arguments for refuting the possibility of a substructure of the quantum mechanics, consisting in particles following continuous trajectories.展开更多
We investigate dynamical phase transitions that are induced by interspecies interaction in a two-species bosonic Josephson junctions （B J J）, based on semi-classical theory. In zero-phase mode, similar to the case o...We investigate dynamical phase transitions that are induced by interspecies interaction in a two-species bosonic Josephson junctions （B J J）, based on semi-classical theory. In zero-phase mode, similar to the case of a single-species B J J, we observe the well-known dynamical phase transition from Josephson oscillation to self-trapping, which can be induced by both enhanced repulsive and attractive interspecies interactions. In π phase mode, dynamical phase transitions are even more interesting and counter- intuitive. We characterize a dynamical phase transition with the merging of two separate phase space domains into one, which is induced by increasing repulsive interspecies interaction. On the other hand, we find that by increasing attractive interspecies interaction, a phase separation of two formally overlapped phase space domains will occur. At last, we reveal that these intriguing dynamical phase transitions are caused by different kinds of bifurcations.展开更多
We construct fermionic-bosonic representations for a class of generalized B（m, n）, C（n）, D（m, n）-graded Lie superalgebras coordinatized by quantum tori with nontrivial central extensions.
In this work we are formulating a new theory for describing the waving nature of a microscopic electric particle. Based on the predictions of the Quantum Oscillatory Modulated Potential—QOMP, for describing the inter...In this work we are formulating a new theory for describing the waving nature of a microscopic electric particle. Based on the predictions of the Quantum Oscillatory Modulated Potential—QOMP, for describing the interaction between two microscopic electric particles, electron-electron, for instance, we are postulating that the waving behavior of these particles may be an attribute of the charges of the particles and not their masses as currently accepted. For a microscopic electric charge, we are presenting new arguments showing that the electric field in the vicinity of a microscopic charge is spatially waving and can be determined as the gradient per unit of charge of this new quantum interaction potential, with use of an appropriated phase factor to account for the behavior of an unbound electron. Differently of what is predicted by the classical Coulomb electric field, when a charged particle is moving under the action of a potential of V volts, the new electric field existing around the charge has the form of a wave packet. For typical values of the potential V, the wavelength of the waving electric field is in very good agreement with those experimentally observed with diffraction of electrons in crystalline solids.展开更多
A bosonic construction (with central charge c = 2) of Lie algebras W1+∞ and W1+∞ (glN), as well as the decompositions into irreducible modules are described. And for W1+∞, when restricted to its Virasoro subalgebra...A bosonic construction (with central charge c = 2) of Lie algebras W1+∞ and W1+∞ (glN), as well as the decompositions into irreducible modules are described. And for W1+∞, when restricted to its Virasoro subalgebra Vir, a bosonic construction and the same decomposition for Vir are obtained.展开更多
Bosonic modes have wide applications in various quantum technologies,such as optical photons for quantum communication,magnons in spin ensembles for quantum information storage and mechanical modes for reversible micr...Bosonic modes have wide applications in various quantum technologies,such as optical photons for quantum communication,magnons in spin ensembles for quantum information storage and mechanical modes for reversible microwave-to-optical quantum transduction.There is emerging interest in utilizing bosonic modes for quantum information processing,with circuit quantum electrodynamics(circuit QED)as one of the leading architectures.Quantum information can be encoded into subspaces of a bosonic superconducting cavity mode with long coherence time.However,standard Gaussian operations(e.g.,beam splitting and two-mode squeezing)are insufficient for universal quantum computing.The major challenge is to introduce additional nonlinear control beyond Gaussian operations without adding significant bosonic loss or decoherence.Here we review recent advances in universal control of a single bosonic code with superconducting circuits,including unitary control,quantum feedback control,drivendissipative control and holonomic dissipative control.Various approaches to entangling different bosonic modes are also discussed.展开更多
We theoretically and numerically investigate the coherence of disordered bosonic gas with effective two- and three-body interactions within a two-site Bose-Hubbard model. By properly adjusting the two- and three-body ...We theoretically and numerically investigate the coherence of disordered bosonic gas with effective two- and three-body interactions within a two-site Bose-Hubbard model. By properly adjusting the two- and three-body interactions and the disorder, the coherence of the system exhibits new and interesting phenomena, including the resonance character of coherence against the disorder in the purely two- or three-body interactions system. More interestingly, the disorder and three-body interactions together can suppress the coherence of the purely three-body interactions system, which is different from the case in which the disorder and two-body interactions together can enhance the coherence in certain values of two.body interaction. Furthermore, when two- or three- body interactions are attractive or repulsive, the phase coherence exhibits completely different phenomena. In particular, if two- or three-body interactions are attractive, the coherence of the system can be significantly enhanced in certain regions. Correspondingly, the phase coherence of the system is strongly related to the effective interaction energy. The results provide a possible way for studying the coherence of bosonic gas with multi-atoms＇ interactions in the presence of the disorder.展开更多
We investigate the sudden birth and sudden death of entanglement of two qubits interacting with uncorrelated structured reservoirs. The system is initially prepared in two-qubit extended Werner-like state. We work out...We investigate the sudden birth and sudden death of entanglement of two qubits interacting with uncorrelated structured reservoirs. The system is initially prepared in two-qubit extended Werner-like state. We work out the dependence of the entanglement dynamics on both non-Markovian environments and the purity of initial state, and show that non-Markovian environments and the purity can control the time of the two-qubit entanglement sudden death and the reservoirs＇ entanglement sudden birth. Furthermore, under the conditions of different purity and initial entangIement, the revival of qubits＇ entanglement can manifest before, simultaneously or even after the disentanglement of their corresponding reservoirs.展开更多
Using the resolution of unity composed of bosonic creation operator＇s eigenkets and annihilation operator＇s un-normalized eigenket, which is a new quantum mechanical representation in contour integration form, we de...Using the resolution of unity composed of bosonic creation operator＇s eigenkets and annihilation operator＇s un-normalized eigenket, which is a new quantum mechanical representation in contour integration form, we derive new contour integration expression of associated Laguerre polynomials L^ρm （｜z｜^2） and its generalized generating function formula. A series of recursive relations regarding to L^ρm （｜z｜^2） are also deduced in the context of the Fock representation by algebraic method.展开更多
From resolving Klein-Gordon equation and Dirac equation in (2+1)-dimensional charged black hole spacetime and using 't Hooft's boundary condition and "quasi-periodic" boundary condition in the thin f...From resolving Klein-Gordon equation and Dirac equation in (2+1)-dimensional charged black hole spacetime and using 't Hooft's boundary condition and "quasi-periodic" boundary condition in the thin film brick wall model of black hole, which is introduced by LIU Weng-Biao and ZHAO Zheng, we obtain the bosonic and fermionic entropy of (2+1)-dimensional charged black hole, and find that the bosonic entropy is three times of fermionic entropy.展开更多
The reduced density matrices （RDMs） of many-body quantum states form a convex set. The boundary of low dimensional projections of this convex set may exhibit nontrivial geometry such as ruled surfaces. In this paper...The reduced density matrices （RDMs） of many-body quantum states form a convex set. The boundary of low dimensional projections of this convex set may exhibit nontrivial geometry such as ruled surfaces. In this paper, we study the physical origins of these ruled surfaces for bosonic systems. The emergence of ruled surfaces was recently proposed as signatures of symmetry- breaking phase. We show that, apart from being signatures of symmetry-brealdng, ruled surfaces can also be the consequence of gapless quantum systems by demonstrating an explicit example in terms of a two-mode Ising model. Our analysis was largely simplified by the quantum de Finetti＇s theorem--in the limit of large system size, these RDMs are the convex set of all the symmetric separable states. To distinguish ruled surfaces originated from gapless systems from those caused by symmetry- breaking, we propose to use the finite size scaling method for the corresponding geometry. This method is then applied to the two-mode XY model, successfully identifying a ruled surface as the consequence of gapless systems.展开更多
We investigate the dynamics of the precision of the parameter estimation in many driven atoms, each of which interacts with a local structured bosonic reservoir respectively. The evolution of quantum states for single...We investigate the dynamics of the precision of the parameter estimation in many driven atoms, each of which interacts with a local structured bosonic reservoir respectively. The evolution of quantum states for single driven atom is described by the time local quantum master equation. The dynamics of the quantum Fisher information for many entangled atoms is obtained by means of the supreoperator mapping. The estimation limit is superior to the standard quantum limit during a characteristic interval. At a given time, the precision of parameter estimation can be improved to a maximal value if the number of entangled atoms is chosen to be an optimal value. The optimal number of entangled atoms is determined by the dynamical property. The decay of quantum Fisher information is accelerated with the increase of the number of entangled atoms.展开更多
基金This work was supported by National Key Research and Development Program of China(Grant No.2017YFA0304303)the National Natu-ral Science Foundation of China(Grant No.11925404 and 11874235,11874342 and 11922411)+1 种基金Anhui Initiative in Quantum Information Technologies(AHY130200)a grant from the Institute for Guo Qiang(No.2019GQG1024),Tsinghua University.
文摘Quantum information is vulnerable to environmental noise and experimental imperfections,hindering the reli-ability of practical quantum information processors.Therefore,quantum error correction(QEC)that can pro-tect quantum information against noise is vital for universal and scalable quantum computation.Among many different experimental platforms,superconducting quantum circuits and bosonic encodings in superconducting microwave modes are appealing for their unprecedented potential in QEC.During the last few years,bosonic QEC is demonstrated to reach the break-even point,i.e.the lifetime of a logical qubit is enhanced to exceed that of any individual components composing the experimental system.Beyond that,universal gate sets and fault-tolerant operations on the bosonic codes are also realized,pushing quantum information processing towards the QEC era.In this article,we review the recent progress of the bosonic codes,including the Gottesman-Kitaev-Preskill codes,cat codes,and binomial codes,and discuss the opportunities of bosonic codes in various quantum applications,ranging from fault-tolerant quantum computation to quantum metrology.We also summarize the challenges associated with the bosonic codes and provide an outlook for the potential research directions in the long terms.
基金funded by the National Natural Science Foundation of China
文摘This report adds three protonic semiconductor models to explain the "abnormally" high electrical conductivity of pure liquid water characterized by the three industrial consensus parameters, the ion product(or pH)and the two ion mobilities. Existence of long-range order in fluid water under numerous daily conditions led us to extend the 1933 Bernal-Fowler hexagonally close packed crystalline Ice Lattice to model liquid water as Melted Ice. Protonic kinetic energy band and bound(trap) pictures provide semiconductor-physics based new models of these three parameters. They are extrapolatable engineered-models for developing novel biological, chemical, electrical, mechanical and medical applications of liquid water.
文摘In this paper we consider a model in which the masses of elementary particles are formed and stabilized thanks to confining potential, which is caused by recoil momentum at emission of specific virtual bosons by particle itself. The calculation of this confining potential Ф(R) is carried out. It is shown that Ф(R) may be in the form const or const depending on continuous or discrete nature of the spectrum of emitted bosons.
文摘The interacting comma 3-vertex for the bosonic open string in the full string basis is derived using the half string overlap relations directly. Thus avoiding the coherent states technique employed in earlier derivations. The resulting form of the interacting 3-vertex turns out to be precisely the desired expression obtained in terms of the full string oscillator modes. This derivation establishes that the comma 3-vertex and Witten’s 3-vertex are identical and therefore are interchangeable.
文摘We construct a class of modules for the twisted multi-loop algebra of type A1 × A1 by applying Wakimoto free bosonic realization. We also discuss the structures and the irreducibility of the Fock space.
基金supported by the National Natural Science Foundation of China(Grant No.11274379)the Research Funds of Renmin University of China(Grant No.14XNLQ07)
文摘The fermionic and bosonic zero modes of the one-dimensional（1D） interacting Kitaev chain at the symmetric point are unveiled. The many-body structures of the Majorana zero modes in the topological region are given explicitly by carrying out a perturbation expansion up to infinite order. We also give the analytic expressions of the bosonic zero modes in the topologically trivial phase. Our results are generalized to the hybrid fermion system comprised of the interacting Kitaev model and the Su–Schrieffer–Heeger（SSH） model, in which we show that these two types of zero modes can coexist in a certain region of its phase diagram.
基金supported by the National Natural Science Foundation of China(Grant Nos.11175113 and 11275123)the Key Project of Natural Science Fund of Anhui Province,China(Grant No.KJ2013A261)
文摘We consider the quantum mechanical SU（2） transformation e^2λJzJ±e^-2λJz = e^±2λJ±as if the meaning of squeezing with e^±2λ being squeezing parameter. By studying SU（2） operators （J±, Jz） from the point of view of squeezing we find that （J±,Jz） can also be realized in terms of 3-mode bosonic operators. Employing this realization, we find the natural representation （the eigenvectors of J＋ or J-） of the 3-mode squeezing operator e^2λJz. The idea of considering quantum SU（2） transformation as if squeezing is liable for us to obtain the new bosonic operator realization of SU（2） and new squeezing operators.
文摘We conjecture the existence of massless neutrinos that are in the line of Standard Model (unable to account for the neutrino mass) but have characteristics that are not accounted for the Standard Model: they use a shorter radial path than the photon and possess bosonic flavors, considered like bosons instead of fermions. We call this theory “neutrino temporal oscillation”. Faced with some experimental comparisons solar neutrinos, neutrinos from SN 1987A, cosmological neutrinos, the theory gives better results, explanations and sense than the complicated theory of neutrino oscillations (transformism). The deficit of detection of solar neutrinos would have been blindly attributed to the “neutrino oscillation” by physicists who quickly concluded that the neutrino and the photon follow the same transverse path. The “OPERA” experiment which measured the speed of neutrinos in 2011 resulted, after a “superluminal” saga, in neutrino speeds consistent with the speed of light, in data that the three existing types of neutrinos cannot explain, with the final outcome of a fourth “sterile” neutrino with non-standard interaction. OPERA findings aren’t just in conflict with existing theory, but other measurements as well. For example, a study from the Kamiokande II experiment in Japan of the supernova SN1987A found that light and neutrinos that departed this exploded star arrived at Earth within hours of each other. Even though measurements of the neutrinos emitted by this supernova strongly suggest that their speeds differ from light by less than one part in a billion, the fact remains that two types of data were collected, and that only one was retained to be consistent with the existing theory. Thus, the OPERA observation is in conflicts with the result of SN1987A, which itself is highly doubtful. And what about the neutrinos and antineutrinos born during the big bang, except that they were never detected and there is nothing to indicate that their speed could be other than that of light. Neutrino physi
文摘It is in general accepted that the concept of continuous trajectories for particles is at odds with the relativistic quantum mechanics. Namely, when examining the evolution of entangled quantum objects according to frames of coordinates in relative move-ment, one gets contradictory trajectories. Such a situation is typically derived from the famous “Hardy’s paradox”. However, it is argued here that if the rationale ignores the principle of quantum contextuality, as happens typically when using Hardy’s thought-experiment, the conclusion—rejection of the assumption of trajectories—is questionable. The issue is exemplified by an additional example: the 101 property of spin 1 bosons implies conflicting trajectories when the singlet state of two such bosons is examined according to frames in relative movement. It is concluded here that in the absence of a rationale which doesn’t violate the quantum contextuality, there are no sufficient arguments for refuting the possibility of a substructure of the quantum mechanics, consisting in particles following continuous trajectories.
基金Acknowledgements This work was supported by the National Natural Science Foundation of China （Grant Nos. 11104217 and 11402199）, the Science Plan Foundation office of the Education Department of Shaanxi Province （Grant No. 14JK1676）, and the Natural Science Foundation of Shaanxi Province （Grant No. 14JQ1022）.
文摘We investigate dynamical phase transitions that are induced by interspecies interaction in a two-species bosonic Josephson junctions （B J J）, based on semi-classical theory. In zero-phase mode, similar to the case of a single-species B J J, we observe the well-known dynamical phase transition from Josephson oscillation to self-trapping, which can be induced by both enhanced repulsive and attractive interspecies interactions. In π phase mode, dynamical phase transitions are even more interesting and counter- intuitive. We characterize a dynamical phase transition with the merging of two separate phase space domains into one, which is induced by increasing repulsive interspecies interaction. On the other hand, we find that by increasing attractive interspecies interaction, a phase separation of two formally overlapped phase space domains will occur. At last, we reveal that these intriguing dynamical phase transitions are caused by different kinds of bifurcations.
文摘We construct fermionic-bosonic representations for a class of generalized B（m, n）, C（n）, D（m, n）-graded Lie superalgebras coordinatized by quantum tori with nontrivial central extensions.
文摘In this work we are formulating a new theory for describing the waving nature of a microscopic electric particle. Based on the predictions of the Quantum Oscillatory Modulated Potential—QOMP, for describing the interaction between two microscopic electric particles, electron-electron, for instance, we are postulating that the waving behavior of these particles may be an attribute of the charges of the particles and not their masses as currently accepted. For a microscopic electric charge, we are presenting new arguments showing that the electric field in the vicinity of a microscopic charge is spatially waving and can be determined as the gradient per unit of charge of this new quantum interaction potential, with use of an appropriated phase factor to account for the behavior of an unbound electron. Differently of what is predicted by the classical Coulomb electric field, when a charged particle is moving under the action of a potential of V volts, the new electric field existing around the charge has the form of a wave packet. For typical values of the potential V, the wavelength of the waving electric field is in very good agreement with those experimentally observed with diffraction of electrons in crystalline solids.
基金Project supported by the National Natural Science Foundation of China (No. 10431040, No.10271047, No.19731004) the Teaching and Research Award Program for Outstanding Young Teachers in Higher Education Institution of the Ministry of Education of China, the Specialized Research Fund for the Doctoral Program of Higher Education of the Ministry of Education of China, the Shanghai Rising-Star Program of the Science and Technology Commission of Shanghai and the Shanghai Priority Academic Discipline of the Education Commission of Shanghai.
文摘A bosonic construction (with central charge c = 2) of Lie algebras W1+∞ and W1+∞ (glN), as well as the decompositions into irreducible modules are described. And for W1+∞, when restricted to its Virasoro subalgebra Vir, a bosonic construction and the same decomposition for Vir are obtained.
基金support from the ARO (W911NF-18-1-0020 and W911NF-18-1-0212)ARO MURI (W911NF-16-1-0349)+3 种基金AFOSR MURI (FA9550-19-1-0399)NSF (EFMA-1640959, OMA-1936118, EEC-1941583)NTT Research, the Packard Foundation (201339273)the Startup Foundation of Institute of Semiconductors, Chinese Academy of Sciences (E0SEBB11)。
文摘Bosonic modes have wide applications in various quantum technologies,such as optical photons for quantum communication,magnons in spin ensembles for quantum information storage and mechanical modes for reversible microwave-to-optical quantum transduction.There is emerging interest in utilizing bosonic modes for quantum information processing,with circuit quantum electrodynamics(circuit QED)as one of the leading architectures.Quantum information can be encoded into subspaces of a bosonic superconducting cavity mode with long coherence time.However,standard Gaussian operations(e.g.,beam splitting and two-mode squeezing)are insufficient for universal quantum computing.The major challenge is to introduce additional nonlinear control beyond Gaussian operations without adding significant bosonic loss or decoherence.Here we review recent advances in universal control of a single bosonic code with superconducting circuits,including unitary control,quantum feedback control,drivendissipative control and holonomic dissipative control.Various approaches to entangling different bosonic modes are also discussed.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11475027,11274255 and 11305132the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grand No 20136203110001+1 种基金the Natural Science Foundation of Gansu Province under Grant No 1506RJYA131the Creation of Science and Technology of Northwest Normal University under Grant Nos NWNU-KJCXGC-03-48 and NWNU-LKQN-12-12
文摘We theoretically and numerically investigate the coherence of disordered bosonic gas with effective two- and three-body interactions within a two-site Bose-Hubbard model. By properly adjusting the two- and three-body interactions and the disorder, the coherence of the system exhibits new and interesting phenomena, including the resonance character of coherence against the disorder in the purely two- or three-body interactions system. More interestingly, the disorder and three-body interactions together can suppress the coherence of the purely three-body interactions system, which is different from the case in which the disorder and two-body interactions together can enhance the coherence in certain values of two.body interaction. Furthermore, when two- or three- body interactions are attractive or repulsive, the phase coherence exhibits completely different phenomena. In particular, if two- or three-body interactions are attractive, the coherence of the system can be significantly enhanced in certain regions. Correspondingly, the phase coherence of the system is strongly related to the effective interaction energy. The results provide a possible way for studying the coherence of bosonic gas with multi-atoms＇ interactions in the presence of the disorder.
基金Supported by the National Natural Science Foundation of China under Grant No.10904033Natural Science Foundation of Hubei Province under Grant No.2009CDA145+1 种基金Educational Commission of Hubei Province under Grant No.D20092204the Postgraduate Programme of Hubei Normal University under Grant No.2007D20
文摘We investigate the sudden birth and sudden death of entanglement of two qubits interacting with uncorrelated structured reservoirs. The system is initially prepared in two-qubit extended Werner-like state. We work out the dependence of the entanglement dynamics on both non-Markovian environments and the purity of initial state, and show that non-Markovian environments and the purity can control the time of the two-qubit entanglement sudden death and the reservoirs＇ entanglement sudden birth. Furthermore, under the conditions of different purity and initial entangIement, the revival of qubits＇ entanglement can manifest before, simultaneously or even after the disentanglement of their corresponding reservoirs.
基金supported by the Specialized Research Fund for the Doctorial Progress of Higher Education of China under Grant No.20070358009
文摘Using the resolution of unity composed of bosonic creation operator＇s eigenkets and annihilation operator＇s un-normalized eigenket, which is a new quantum mechanical representation in contour integration form, we derive new contour integration expression of associated Laguerre polynomials L^ρm （｜z｜^2） and its generalized generating function formula. A series of recursive relations regarding to L^ρm （｜z｜^2） are also deduced in the context of the Fock representation by algebraic method.
文摘From resolving Klein-Gordon equation and Dirac equation in (2+1)-dimensional charged black hole spacetime and using 't Hooft's boundary condition and "quasi-periodic" boundary condition in the thin film brick wall model of black hole, which is introduced by LIU Weng-Biao and ZHAO Zheng, we obtain the bosonic and fermionic entropy of (2+1)-dimensional charged black hole, and find that the bosonic entropy is three times of fermionic entropy.
基金supported by the Natural Sciences and Engineering Research Council of Canada, Canadian Institute for Advanced Research, the Program for the Outstanding Innovative Teams of Higher Learning Institutions of Shanxi, and the Perimeter Institute for Theoretical PhysicsResearch at Perimeter Institute was supported by the Government of Canada through Industry Canada and by the Province of Ontario through the Ministry of Economic Development & Innovation+1 种基金Zheng-Xin Liu was supported by the Research Funds of Remin University of China (Grant No. 15XNFL19)the National Natural Science Foundation of China (Grant No. 11574392)
文摘The reduced density matrices （RDMs） of many-body quantum states form a convex set. The boundary of low dimensional projections of this convex set may exhibit nontrivial geometry such as ruled surfaces. In this paper, we study the physical origins of these ruled surfaces for bosonic systems. The emergence of ruled surfaces was recently proposed as signatures of symmetry- breaking phase. We show that, apart from being signatures of symmetry-brealdng, ruled surfaces can also be the consequence of gapless quantum systems by demonstrating an explicit example in terms of a two-mode Ising model. Our analysis was largely simplified by the quantum de Finetti＇s theorem--in the limit of large system size, these RDMs are the convex set of all the symmetric separable states. To distinguish ruled surfaces originated from gapless systems from those caused by symmetry- breaking, we propose to use the finite size scaling method for the corresponding geometry. This method is then applied to the two-mode XY model, successfully identifying a ruled surface as the consequence of gapless systems.
基金Supported by the National Natural Science Foundation of China under Grant No.11274054the Creative Project of Graduate in University of Suzhou Science and Technology in No.SKCX16-006the Innovation Project of Graduate Education of Jiangsu Province No.JGLX15-150
文摘We investigate the dynamics of the precision of the parameter estimation in many driven atoms, each of which interacts with a local structured bosonic reservoir respectively. The evolution of quantum states for single driven atom is described by the time local quantum master equation. The dynamics of the quantum Fisher information for many entangled atoms is obtained by means of the supreoperator mapping. The estimation limit is superior to the standard quantum limit during a characteristic interval. At a given time, the precision of parameter estimation can be improved to a maximal value if the number of entangled atoms is chosen to be an optimal value. The optimal number of entangled atoms is determined by the dynamical property. The decay of quantum Fisher information is accelerated with the increase of the number of entangled atoms.
