As one of the most promising candidates for implementing quantum computers, superconducting qubits（SQs） are adopted for fast generating the Greenberger–Horne–Zeilinger（GHZ） state by using invariants-based shortc...As one of the most promising candidates for implementing quantum computers, superconducting qubits（SQs） are adopted for fast generating the Greenberger–Horne–Zeilinger（GHZ） state by using invariants-based shortcuts. Three SQs are separated and connected by two coplanar waveguide resonators（CPWRs） capacitively. The complicated system is skillfully simplified to a three-state system, and a GHZ state among three SQs is fast generated with a very high fidelity and simple driving pulses. Numerical simulations indicate the scheme is insensitive to parameter deviations. Besides, the robustness of the scheme against decoherence is discussed in detail.展开更多
A multiparty simultaneous quantum identity authentication protocol based on Creenberger-Horne-Zeilinger （GHZ） states is proposed. The multi-user can be authenticated by a trusted third party （TTP） simultaneously. ...A multiparty simultaneous quantum identity authentication protocol based on Creenberger-Horne-Zeilinger （GHZ） states is proposed. The multi-user can be authenticated by a trusted third party （TTP） simultaneously. Compared with the scheme proposed recently （Wang et al 2006 Chin. Phys. Lett. 23（9） 2360）, the proposed scheme has the advantages of consuming fewer quantum and classical resources and lessening the difficulty and intensity of necessary operations.展开更多
We present two schemes for realizing the remote preparation of a Greenberger-Horne-Zeilinger （GHZ） state. The first scheme is to remotely prepare a general N-particle GHZ state with two steps. One is to prepare a qu...We present two schemes for realizing the remote preparation of a Greenberger-Horne-Zeilinger （GHZ） state. The first scheme is to remotely prepare a general N-particle GHZ state with two steps. One is to prepare a qubit state by using finite classical bits from sender to receiver via a two-particle entangled state, and the other is that the receiver introduces N - 1 additional particles and performs N - 1 controlled-not （C-Not） operations. The second scheme is to remotely prepare an N-atom GHZ state via a two-atom entangled state in cavity quantum electrodynamics （QED）. The two schemes require only a two-particle entangled state used as a quantum channel, so we reduce the requirement for entanglement.展开更多
We propose two schemes for generating Greenberger-Horne-Zeilinger and W states of three distant atoms. In the present schemes, the atoms are individually trapped in three spatially separated optical cavities coupled b...We propose two schemes for generating Greenberger-Horne-Zeilinger and W states of three distant atoms. In the present schemes, the atoms are individually trapped in three spatially separated optical cavities coupled by two optical fibres. Performing an adiabatic passage along dark states, the population of cavities and fibres excited is negligible under certain conditions. In addition, the spontaneous decay of atoms is also efficiently suppressed based on our proposals. Furthermore, the discussion about the entanglement fidelity is given and we point out that our schemes work robustly with small fluctuations of experimental parameters.展开更多
We propose a scheme to generate a Greenberger-Horn-Zeilinger （GHZ） state of four atoms trapped in a two-mode optical cavity via an adiabatic passage. The scheme is robust against moderate fluctuations of the experim...We propose a scheme to generate a Greenberger-Horn-Zeilinger （GHZ） state of four atoms trapped in a two-mode optical cavity via an adiabatic passage. The scheme is robust against moderate fluctuations of the experimental parameters. Numerical calculations show that the excited probabilities of both the cavity modes and the atoms are tiny and depend on the pulse peaks of the classical laser fields. For certain decoherence due to the atomic spontaneous emission and the cavity decay, there exits a range of pulse peaks to get a high fidelity.展开更多
A quantum broadcast communication and authentication protocol with a quantum one-time pad based on the Greenberger-Horne-Zeilinger state is proposed. A binary string is used to express the identity of the receiver, wh...A quantum broadcast communication and authentication protocol with a quantum one-time pad based on the Greenberger-Horne-Zeilinger state is proposed. A binary string is used to express the identity of the receiver, which is encoded as a single sequence of photons. The encoded photon sequence acts as a detection sequence and implements au- thentication. An XOR operation serves as a one-time pad and is used to ensure the security of the protocol. The binary string is reused even in a noisy channel and proves to be unconditionally secure. In contrast with the protocols proposed by Wang et al. [Chin. Phys. 16 1868 （2007）] and Yang et al. [Chin. Phys. B 19 070304 （2010）], the protocol in this study implements the identity authentication with a reusable binary string; no hash function or local unitary operation is used. The protocol in this study is also easier to implement and highly efficient without losing security.展开更多
We propose a potentially practical scheme to generate two-atom maximally entangled states by the large-detuning interaction between two three-level A-type atoms and coherent optical fields. Conditioned on the results ...We propose a potentially practical scheme to generate two-atom maximally entangled states by the large-detuning interaction between two three-level A-type atoms and coherent optical fields. Conditioned on the results of detecting cavity field, four pairs of atomic maximally entangled states with unity fidelity and high successful probability can be prepared. We also investigate the influence of the cavity dissipation on the generated entangled states and discuss the experimental feasibility of our scheme.展开更多
A scheme for three-party quantum secret sharing of a private key is presented with single photons. The agent Bob first prepares a sequence of single photons with two biased bases and then sends them to the boss Alice ...A scheme for three-party quantum secret sharing of a private key is presented with single photons. The agent Bob first prepares a sequence of single photons with two biased bases and then sends them to the boss Alice who checks the security of the transmission with measurements and produces some decoy photons by rearranging the orders of some sample photons. Alice encodes her bits with two unitary operations on the photons and then sends them to the other agent. The security of this scheme is equivalent to that in the modified Bennett Brassard 1984 quantum key distribution protocol. Moreover, each photon can carry one bit of the private key and the intrinsic efficiency for qubits and the total efficiency both approach the maximal value 100% when the number of the bits in the key is very large.展开更多
We propose a multi-bit dense coding scheme by using only an Einstein-Podolsky-Rosen（EPR） channel and assistant qubits.It is shown that no matter how many classical bits there are,the quantum channel is always a Bell...We propose a multi-bit dense coding scheme by using only an Einstein-Podolsky-Rosen（EPR） channel and assistant qubits.It is shown that no matter how many classical bits there are,the quantum channel is always a Bell state.The present dense coding process can also prepare non-local multi-particle Greenberger-Horne-Zeilinger（GHZ） states at one of the participants.The quantum circuits for this dense coding process are constructed,the deterministic implementation method in an optical system based on the cross-Kerr nonlinearities is shown.展开更多
We design proposals to generate a remote Greenberger-Horne-Zeilinger（GHZ） state and a W state of nitrogenvacancy（NV） centers coupled to microtoroidal resonators（MTRs） through noisy channels by utilizing time-bin...We design proposals to generate a remote Greenberger-Horne-Zeilinger（GHZ） state and a W state of nitrogenvacancy（NV） centers coupled to microtoroidal resonators（MTRs） through noisy channels by utilizing time-bin encoding processes and fast-optical-switch-based polarization rotation operations.The polarization and phase noise induced by noisy channels generally affect the time of state generation but not its success probability and fidelity.Besides,the above proposals can be generalized to n-qubit between two or among n remote nodes with success probability unity under ideal conditions.Furthennore,the proposals are robust for regular noise-changeable channels for the n-node case.This method is also useful in other remote quantum information processing tasks through noisy channels.展开更多
We present an alternative scheme for implementing the unconventional geometric two-qubit phase gate and prepar- ing multiqubit entanglement by using a frequency-modulated laser field to simultaneously illuminate all i...We present an alternative scheme for implementing the unconventional geometric two-qubit phase gate and prepar- ing multiqubit entanglement by using a frequency-modulated laser field to simultaneously illuminate all ions. Selecting the index of modulation yields selective mechanisms for coupling and decoupling between the internal and the external states of the ions. By the selective mechanisms, we obtain the unconventional geometric two-qubit phase gate, multiparticle Greenberger-Horne-Zeilinger states and highly entangled cluster states. Our scheme is insensitive to the thermal motion of the ions.展开更多
We present a scheme to generate cluster states with many scheme, no transfer of quantum information between the atoms in cavity QED via Raman transition. In this atoms and cavities is required, the cavity fields are o...We present a scheme to generate cluster states with many scheme, no transfer of quantum information between the atoms in cavity QED via Raman transition. In this atoms and cavities is required, the cavity fields are only virtually excited and thus the cavity decay is suppressed during the generation of cluster states. The atoms are always populated in the two ground states. Therefore, the scheme is insensitive to the atomic spontaneous emission and cavity decay. We also show how to transfer quantum information from one atom to another.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11464046)
文摘As one of the most promising candidates for implementing quantum computers, superconducting qubits（SQs） are adopted for fast generating the Greenberger–Horne–Zeilinger（GHZ） state by using invariants-based shortcuts. Three SQs are separated and connected by two coplanar waveguide resonators（CPWRs） capacitively. The complicated system is skillfully simplified to a three-state system, and a GHZ state among three SQs is fast generated with a very high fidelity and simple driving pulses. Numerical simulations indicate the scheme is insensitive to parameter deviations. Besides, the robustness of the scheme against decoherence is discussed in detail.
基金supported by the National High-Tech Research,Development Plan of China (Grant Nos 2006AA01Z440,2009AA012441 and 2009AA012437)National Basic Research Program of China (973 Program) (Grant No 2007CB311100)+5 种基金the National Natural Science Foundation of China (Grant Nos 60873191 and 60821001)the Scientific Research Common Program of Beijing Municipal Commission of Education (Grant No KM200810005004)Beijing Natural Science Foundation (Grant No 1093015)the Open Research Fund of National Mobile Communications Research Laboratory,Southeast Universitythe ISN Open FoundationScience and Technology Program of Beijing (Grant No Z07000100720706)
文摘A multiparty simultaneous quantum identity authentication protocol based on Creenberger-Horne-Zeilinger （GHZ） states is proposed. The multi-user can be authenticated by a trusted third party （TTP） simultaneously. Compared with the scheme proposed recently （Wang et al 2006 Chin. Phys. Lett. 23（9） 2360）, the proposed scheme has the advantages of consuming fewer quantum and classical resources and lessening the difficulty and intensity of necessary operations.
文摘We present two schemes for realizing the remote preparation of a Greenberger-Horne-Zeilinger （GHZ） state. The first scheme is to remotely prepare a general N-particle GHZ state with two steps. One is to prepare a qubit state by using finite classical bits from sender to receiver via a two-particle entangled state, and the other is that the receiver introduces N - 1 additional particles and performs N - 1 controlled-not （C-Not） operations. The second scheme is to remotely prepare an N-atom GHZ state via a two-atom entangled state in cavity quantum electrodynamics （QED）. The two schemes require only a two-particle entangled state used as a quantum channel, so we reduce the requirement for entanglement.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 90503010,10874050,10975054,91021011 and 11005057)National Basic Research Program of China (Grant No. 2005CB724508)the Foundation from the Ministry of Education of China (Grant No. 200804870051)
文摘We propose two schemes for generating Greenberger-Horne-Zeilinger and W states of three distant atoms. In the present schemes, the atoms are individually trapped in three spatially separated optical cavities coupled by two optical fibres. Performing an adiabatic passage along dark states, the population of cavities and fibres excited is negligible under certain conditions. In addition, the spontaneous decay of atoms is also efficiently suppressed based on our proposals. Furthermore, the discussion about the entanglement fidelity is given and we point out that our schemes work robustly with small fluctuations of experimental parameters.
基金Project supported by the National Basic Research Program of China (Grant No. 2012CB921601)the National Natural Science Foundation of China (Grant No. 10974028)the Doctoral Foundation of the Ministry of Education of China (Grant No. 20093514110009)
文摘We propose a scheme to generate a Greenberger-Horn-Zeilinger （GHZ） state of four atoms trapped in a two-mode optical cavity via an adiabatic passage. The scheme is robust against moderate fluctuations of the experimental parameters. Numerical calculations show that the excited probabilities of both the cavity modes and the atoms are tiny and depend on the pulse peaks of the classical laser fields. For certain decoherence due to the atomic spontaneous emission and the cavity decay, there exits a range of pulse peaks to get a high fidelity.
基金Project supported by the National Natural Science Foundation of China(Grant No.61370203)the Science and Technology Support Project of Sichuan Province,China(Grant No.13ZC2138)the Fund for Young Persons Project of Sichuan Province,China(Grant No.12ZB017)
文摘A quantum broadcast communication and authentication protocol with a quantum one-time pad based on the Greenberger-Horne-Zeilinger state is proposed. A binary string is used to express the identity of the receiver, which is encoded as a single sequence of photons. The encoded photon sequence acts as a detection sequence and implements au- thentication. An XOR operation serves as a one-time pad and is used to ensure the security of the protocol. The binary string is reused even in a noisy channel and proves to be unconditionally secure. In contrast with the protocols proposed by Wang et al. [Chin. Phys. 16 1868 （2007）] and Yang et al. [Chin. Phys. B 19 070304 （2010）], the protocol in this study implements the identity authentication with a reusable binary string; no hash function or local unitary operation is used. The protocol in this study is also easier to implement and highly efficient without losing security.
基金Supported by the National Natural Science Foundation of China under Grant No 10374007, the Natural Science Foundation of Hunan Province under Grant No 06jj50014, and the Natural Science Foundation of the Education Department of Hunan Province under Grant No 05C696.
文摘We propose a potentially practical scheme to generate two-atom maximally entangled states by the large-detuning interaction between two three-level A-type atoms and coherent optical fields. Conditioned on the results of detecting cavity field, four pairs of atomic maximally entangled states with unity fidelity and high successful probability can be prepared. We also investigate the influence of the cavity dissipation on the generated entangled states and discuss the experimental feasibility of our scheme.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10604008 and 10435020 and Beijing Education Committee under Grant No XK100270454.
文摘A scheme for three-party quantum secret sharing of a private key is presented with single photons. The agent Bob first prepares a sequence of single photons with two biased bases and then sends them to the boss Alice who checks the security of the transmission with measurements and produces some decoy photons by rearranging the orders of some sample photons. Alice encodes her bits with two unitary operations on the photons and then sends them to the other agent. The security of this scheme is equivalent to that in the modified Bennett Brassard 1984 quantum key distribution protocol. Moreover, each photon can carry one bit of the private key and the intrinsic efficiency for qubits and the total efficiency both approach the maximal value 100% when the number of the bits in the key is very large.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 61068001 and 11147174)
文摘We propose a multi-bit dense coding scheme by using only an Einstein-Podolsky-Rosen（EPR） channel and assistant qubits.It is shown that no matter how many classical bits there are,the quantum channel is always a Bell state.The present dense coding process can also prepare non-local multi-particle Greenberger-Horne-Zeilinger（GHZ） states at one of the participants.The quantum circuits for this dense coding process are constructed,the deterministic implementation method in an optical system based on the cross-Kerr nonlinearities is shown.
基金supported by the National Natural Science Foundation of China(Grant Nos.11264042,61465013,11465020,and 11165015)the Program for Chun Miao Excellent Talents of Jilin Provincial Department of Education(Grant No.201316)the Talent Program of Yanbian University of China(Grant No.950010001)
文摘We design proposals to generate a remote Greenberger-Horne-Zeilinger（GHZ） state and a W state of nitrogenvacancy（NV） centers coupled to microtoroidal resonators（MTRs） through noisy channels by utilizing time-bin encoding processes and fast-optical-switch-based polarization rotation operations.The polarization and phase noise induced by noisy channels generally affect the time of state generation but not its success probability and fidelity.Besides,the above proposals can be generalized to n-qubit between two or among n remote nodes with success probability unity under ideal conditions.Furthennore,the proposals are robust for regular noise-changeable channels for the n-node case.This method is also useful in other remote quantum information processing tasks through noisy channels.
基金Project supported by the National Basic Research Program of China (Grant No. 2005CB724508)the Scientific Research Foundation of Jiangxi Provincial Department of Education,China (Grant No. GJJ10133)the Foundation of Talent of Jinggangof Jiangxi Province,China (Grant No. 2008DQ00400)
文摘We present an alternative scheme for implementing the unconventional geometric two-qubit phase gate and prepar- ing multiqubit entanglement by using a frequency-modulated laser field to simultaneously illuminate all ions. Selecting the index of modulation yields selective mechanisms for coupling and decoupling between the internal and the external states of the ions. By the selective mechanisms, we obtain the unconventional geometric two-qubit phase gate, multiparticle Greenberger-Horne-Zeilinger states and highly entangled cluster states. Our scheme is insensitive to the thermal motion of the ions.
基金Supported by the National Natural Science Foundation of China under Grant No 60478029.
文摘We present a scheme to generate cluster states with many scheme, no transfer of quantum information between the atoms in cavity QED via Raman transition. In this atoms and cavities is required, the cavity fields are only virtually excited and thus the cavity decay is suppressed during the generation of cluster states. The atoms are always populated in the two ground states. Therefore, the scheme is insensitive to the atomic spontaneous emission and cavity decay. We also show how to transfer quantum information from one atom to another.
