We propose two schemes for the generation of the Wn state with three atoms separately trapped in two distant cavities coupled by an optical fibre. One is implemented by controlling the interaction time, the other is i...We propose two schemes for the generation of the Wn state with three atoms separately trapped in two distant cavities coupled by an optical fibre. One is implemented by controlling the interaction time, the other is implemented via the adiabatic passage. The influence of various decoherence processes, such as spontaneous emission of the utoma and photon leakages of the cavities and the optical fibre, on the fidelity is also investigated. It is found that the Wn state can be generated with high fidelity even when these decoherence processes are present.展开更多
We introduce an adiabatic long-range quantum communication proposal based on a quantum dot array.By adiabatically varying the external gate voltage applied on the system,the quantum information encoded in the electron...We introduce an adiabatic long-range quantum communication proposal based on a quantum dot array.By adiabatically varying the external gate voltage applied on the system,the quantum information encoded in the electron can be transported from one end dot to another.We numerically solve the schr dinger equation for a system with a given number of quantum dots.It is shown that this scheme is a simple and efficient protocol to coherently manipulate the population transfer under suitable gate pulses.The dependence of the energy gap and the transfer time on system parameters is analyzed and shown numerically.We also investigate the adiabatic passage in a more realistic system in the presence of inevitable fabrication imperfections.This method provides guidance for future realizations of adiabatic quantum state transfer in experiments.展开更多
Stimulated adiabatic passage has been extensively studied to achieve robust and selective population transfer in quantum systems. Recently, the quantum-classic analogy has been rapidly developing and can be considered...Stimulated adiabatic passage has been extensively studied to achieve robust and selective population transfer in quantum systems. Recently, the quantum-classic analogy has been rapidly developing and can be considered responsible for the implementation of the adiabatic transfer of sound energy in cavity chain systems. In this article, we investigate the adiabatic transfer of sound energy between two topological end states in the Su-Schrieffer-Heeger(SSH) cavity chain, which can be considered to be the acoustic analog of the quantum chirped-pulse excitation. The topological adiabatic passage in SSH cavity chain has two categories. When the single-cavity resonance frequencies on the sublattices A and B in the SSH cavity chain do not switch their spectrum positions, the topologically protected adiabatic evolution results in the returning passage of the sound excited in one end cavity. When a level crossing with single-cavity resonance frequencies on the sublattices A and B exhibits switch in the frequency spectrum, acoustic energy is observed to be topologically pumped between the two end cavities of the SSH chain.展开更多
A scheme for creating an arbitrary coherent superposition of two atomic states in serial multi-A-type system is proposed. This technique with the application of a control field is based on the existence of two degener...A scheme for creating an arbitrary coherent superposition of two atomic states in serial multi-A-type system is proposed. This technique with the application of a control field is based on the existence of two degenerate dark states and their interaction. The mixing of the dark states can be controlled by changing the relative delay time of the control pulse. One can get any desired superposition by changing the delay time of the control pulse.展开更多
Based on the idea of adiabatic evolution, we propose two probabilistic but simple schemes for generating maximally entangled states for two distant atoms and concentrating unknown atomic entangled states. Taking advan...Based on the idea of adiabatic evolution, we propose two probabilistic but simple schemes for generating maximally entangled states for two distant atoms and concentrating unknown atomic entangled states. Taking advantage of adiabatic passage, the atoms have no probability of being excited and thus the atomic spontaneous emission is suppressed. Furthermore, in the two schemes accurate adjustment of the interaction time is not required.展开更多
In the present paper, we investigate the instability, adiabaticity, and controlling effects of external fields for a dark state in a homonuclear atom-tetramer conversion that is implemented by a generalized stimulated...In the present paper, we investigate the instability, adiabaticity, and controlling effects of external fields for a dark state in a homonuclear atom-tetramer conversion that is implemented by a generalized stimulated Raman adiabatic passage. We analytically obtain the regions for the appearance of dynamical instability and study the adiabatic evolution by a newly defined adiabatic fidelity. Moreover, the effects of the external field parameters and the spontaneous emissions on the conversion efficiency are also investigated.展开更多
Full-dimensional adiabatic potential energy surfaces of the electronic ground state X and nine excited states A,I,B,C,D,D',D'',E' and F of H_(2)O molecule are developed at the level of internally contr...Full-dimensional adiabatic potential energy surfaces of the electronic ground state X and nine excited states A,I,B,C,D,D',D'',E' and F of H_(2)O molecule are developed at the level of internally contracted multireference configuration interaction with the Davidson correction.The potential energy surfaces are fitted by using Gaussian process regression combining permutation invariant polynomials.With a large selected active space and extra diffuse basis set to describe these Rydberg states,the calculated vertical excited energies and equilibrium geometries are in good agreement with the previous theoretical and experimental values.Compared with the well-investigated photodissociation of the first three low-lying states,both theoretical and experimental studies on higher states are still limited.In this work,we focus on all the three channels of the highly excited state,which are directly involved in the vacuum ultraviolet photodissociation of water.In particular,some conical intersections of D-E',E'-F,A-I and I-C states are clearly illustrated for the first time based on the newly developed potential energy surfaces(PESs).The nonadiabatic dissociation pathways for these excited states are discussed in detail,which may shed light on the photodissociation mechanisms for these highly excited states.展开更多
Cross polarization(CP)is a widely used solid-state nuclear magnetic resonance(NMR)technique for enhancing the polarization of dilute S spins from much larger polarization of abundant I spins such as 1 H.To achieve suc...Cross polarization(CP)is a widely used solid-state nuclear magnetic resonance(NMR)technique for enhancing the polarization of dilute S spins from much larger polarization of abundant I spins such as 1 H.To achieve such a polarization transfer,the I spin should either be spin-locked or be converted to the dipolar ordered state through adiabatic demagnetization in the rotating frame.In this work,we analyze the spin dynamics of the Hartmann-Hahn CP(HHCP)utilizing the 1 H spin-locking,and the dipolar-order CP(DOCP)having the 1 H adiabatic demagnetization.We further propose an adiabatic demagnetization CP(ADCP)where a constant radio-frequency pulse is applied on the S spin while 1 H is adiabatically demagnetized.Our analyses indicate that ADCP utilizes the adiabatic passage to effectively achieve the polarization transfer from the 1 H to S spins.In addition,the dipolar ordered state generated during the 1 H demagnetization process could also be converted into the observable S polarization through DOCP,further enhancing the polarized signals.It is shown by both static and magic-angle-spinning(MAS)NMR experiments that ADCP has dramatically broadened the CP matching condition over the other CP schemes.Various samples have been used to demonstrate the polarization transfer efficiency of this newly proposed ADCP scheme.展开更多
A scheme for the realization of a universal quantum cloning machine is proposed in this paper. The present protocol does not need the vibrational mode to act as the memory and it is robust against small changes of exp...A scheme for the realization of a universal quantum cloning machine is proposed in this paper. The present protocol does not need the vibrational mode to act as the memory and it is robust against small changes of experimental parameters due to adiabatic passages. Furthermore, the scheme may be realized based on current technology.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 11074072)
文摘We propose two schemes for the generation of the Wn state with three atoms separately trapped in two distant cavities coupled by an optical fibre. One is implemented by controlling the interaction time, the other is implemented via the adiabatic passage. The influence of various decoherence processes, such as spontaneous emission of the utoma and photon leakages of the cavities and the optical fibre, on the fidelity is also investigated. It is found that the Wn state can be generated with high fidelity even when these decoherence processes are present.
基金support of the National Natural Science Foundation of China (Grant Nos. 10847150 and 11105086)the Shandong Provincial Natural Science Foundation (Grant Nos. ZR2009AM026 and BS2011-DX029)+1 种基金the Basic Scientific Research Project of Qingdao (Grant No.11-2-4-4-(6)-jch)the Basic Scientific Research Business Expenses of the Central University and Open Project of Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education,Lanzhou University (Grant No. LZUMMM2011001) for financial support
文摘We introduce an adiabatic long-range quantum communication proposal based on a quantum dot array.By adiabatically varying the external gate voltage applied on the system,the quantum information encoded in the electron can be transported from one end dot to another.We numerically solve the schr dinger equation for a system with a given number of quantum dots.It is shown that this scheme is a simple and efficient protocol to coherently manipulate the population transfer under suitable gate pulses.The dependence of the energy gap and the transfer time on system parameters is analyzed and shown numerically.We also investigate the adiabatic passage in a more realistic system in the presence of inevitable fabrication imperfections.This method provides guidance for future realizations of adiabatic quantum state transfer in experiments.
基金supported by the National Natural Science Foundation of China (Grant Nos.11674119,11774297,11690030,and 11690032)support from the General Research Fund of Hong Kong Research Grants Council (Grant No.15205219)。
文摘Stimulated adiabatic passage has been extensively studied to achieve robust and selective population transfer in quantum systems. Recently, the quantum-classic analogy has been rapidly developing and can be considered responsible for the implementation of the adiabatic transfer of sound energy in cavity chain systems. In this article, we investigate the adiabatic transfer of sound energy between two topological end states in the Su-Schrieffer-Heeger(SSH) cavity chain, which can be considered to be the acoustic analog of the quantum chirped-pulse excitation. The topological adiabatic passage in SSH cavity chain has two categories. When the single-cavity resonance frequencies on the sublattices A and B in the SSH cavity chain do not switch their spectrum positions, the topologically protected adiabatic evolution results in the returning passage of the sound excited in one end cavity. When a level crossing with single-cavity resonance frequencies on the sublattices A and B exhibits switch in the frequency spectrum, acoustic energy is observed to be topologically pumped between the two end cavities of the SSH chain.
文摘A scheme for creating an arbitrary coherent superposition of two atomic states in serial multi-A-type system is proposed. This technique with the application of a control field is based on the existence of two degenerate dark states and their interaction. The mixing of the dark states can be controlled by changing the relative delay time of the control pulse. One can get any desired superposition by changing the delay time of the control pulse.
文摘Based on the idea of adiabatic evolution, we propose two probabilistic but simple schemes for generating maximally entangled states for two distant atoms and concentrating unknown atomic entangled states. Taking advantage of adiabatic passage, the atoms have no probability of being excited and thus the atomic spontaneous emission is suppressed. Furthermore, in the two schemes accurate adjustment of the interaction time is not required.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11005055,11075020,and 11204117)the National Fundamental Research Programme of China(Grant No.2011CB921503)+1 种基金the Ph.D.Programs Foundation of Liaoning Provincial Science and Technology Bureau(GrantNo.201103778)the Higher School Excellent Researcher Award Program from the Educational Department of Liaoning Province of China(GrantNo.LJQ2011005)
文摘In the present paper, we investigate the instability, adiabaticity, and controlling effects of external fields for a dark state in a homonuclear atom-tetramer conversion that is implemented by a generalized stimulated Raman adiabatic passage. We analytically obtain the regions for the appearance of dynamical instability and study the adiabatic evolution by a newly defined adiabatic fidelity. Moreover, the effects of the external field parameters and the spontaneous emissions on the conversion efficiency are also investigated.
基金supported by the National Natural Science Foundation of China(No.12047532,No.21733006,No.22073042,and No.22122302)。
文摘Full-dimensional adiabatic potential energy surfaces of the electronic ground state X and nine excited states A,I,B,C,D,D',D'',E' and F of H_(2)O molecule are developed at the level of internally contracted multireference configuration interaction with the Davidson correction.The potential energy surfaces are fitted by using Gaussian process regression combining permutation invariant polynomials.With a large selected active space and extra diffuse basis set to describe these Rydberg states,the calculated vertical excited energies and equilibrium geometries are in good agreement with the previous theoretical and experimental values.Compared with the well-investigated photodissociation of the first three low-lying states,both theoretical and experimental studies on higher states are still limited.In this work,we focus on all the three channels of the highly excited state,which are directly involved in the vacuum ultraviolet photodissociation of water.In particular,some conical intersections of D-E',E'-F,A-I and I-C states are clearly illustrated for the first time based on the newly developed potential energy surfaces(PESs).The nonadiabatic dissociation pathways for these excited states are discussed in detail,which may shed light on the photodissociation mechanisms for these highly excited states.
基金supported by the NSF Cooperative Agreement DMR-1644779the State of Florida.X.H.P.acknowledges the supports from the National Key R&D Program of China(Grants No.2018YFA0306600)+1 种基金the National Science Foundation of China(Grants No.11927811,12150014)Anhui Initiative in Quantum Information Technologies(Grant No.AHY050000).
文摘Cross polarization(CP)is a widely used solid-state nuclear magnetic resonance(NMR)technique for enhancing the polarization of dilute S spins from much larger polarization of abundant I spins such as 1 H.To achieve such a polarization transfer,the I spin should either be spin-locked or be converted to the dipolar ordered state through adiabatic demagnetization in the rotating frame.In this work,we analyze the spin dynamics of the Hartmann-Hahn CP(HHCP)utilizing the 1 H spin-locking,and the dipolar-order CP(DOCP)having the 1 H adiabatic demagnetization.We further propose an adiabatic demagnetization CP(ADCP)where a constant radio-frequency pulse is applied on the S spin while 1 H is adiabatically demagnetized.Our analyses indicate that ADCP utilizes the adiabatic passage to effectively achieve the polarization transfer from the 1 H to S spins.In addition,the dipolar ordered state generated during the 1 H demagnetization process could also be converted into the observable S polarization through DOCP,further enhancing the polarized signals.It is shown by both static and magic-angle-spinning(MAS)NMR experiments that ADCP has dramatically broadened the CP matching condition over the other CP schemes.Various samples have been used to demonstrate the polarization transfer efficiency of this newly proposed ADCP scheme.
基金The project supported by National Natural Science Foundation of China under Grant Nos.10574022 and 10575022the Natural Science Foundation of Fujian Province under Grant Nos.Z0512006 and A0210014
文摘A scheme for the realization of a universal quantum cloning machine is proposed in this paper. The present protocol does not need the vibrational mode to act as the memory and it is robust against small changes of experimental parameters due to adiabatic passages. Furthermore, the scheme may be realized based on current technology.
