An alternative scheme is presented for teleportation of a two-atom entangled state in cavity quantum electrodynamics （QED）. It is based on the resonant atom-cavity field interaction. In the scheme, only one cavity i...An alternative scheme is presented for teleportation of a two-atom entangled state in cavity quantum electrodynamics （QED）. It is based on the resonant atom-cavity field interaction. In the scheme, only one cavity is involved, and the number of the atoms needed to be detected is decreased compared with the previous scheme. Since the resonant atom-cavity field interaction greatly reduces the interaction time, the decoherence effect can be effectively suppressed during the teleportation process. The experimental feasibility of the scheme is discussed. The scheme can easily be generalized to the teleportation of N-atom Greeninger-Horne-Zeilinger （GHZ） entangled states. The number of atoms needed to be detected does not increase as the number of the atoms in the GHZ state increases.展开更多
We propose a scheme to prepare many two-mode cavities into one-dimensional cluster states in the context of cavity QED. The left-circularly polarized state and right-circularly polarized state of the cavity are encode...We propose a scheme to prepare many two-mode cavities into one-dimensional cluster states in the context of cavity QED. The left-circularly polarized state and right-circularly polarized state of the cavity are encoded as the logic zero and one of the qubits. In the scheme, the atomic spontaneous emission is suppressed, and the fidelity is unaffected by the cavity decay on the assumption that the detection efficiencies of all the photondetectors are 1.展开更多
The quantum swap gate is one of the most useful gates for quantum computation. Two-qubit entanglement and a controlled-NOT quantum gate in a neutral Rydberg atom system have been achieved in recent experiments. It is ...The quantum swap gate is one of the most useful gates for quantum computation. Two-qubit entanglement and a controlled-NOT quantum gate in a neutral Rydberg atom system have been achieved in recent experiments. It is therefore very interesting to propose a scheme here for swapping a quantum state between two trapped neutral atoms via the Rydberg blockade mechanism. The atoms interact with a sequence of laser pulses without individual addressing. The errors of the swap gate due to imprecision of pulse length, finite Rydberg interaction, and atomic spontaneous emission are discussed.展开更多
This paper shows that, based on the single-photon JC model depicting the resonant interaction of a two-level atom with a single cavity mode, an unknown atomic state and cavity photon superposition state can be faithfu...This paper shows that, based on the single-photon JC model depicting the resonant interaction of a two-level atom with a single cavity mode, an unknown atomic state and cavity photon superposition state can be faithfully telcported with only a single measurement. The scheme is probabilistie, its success lies on the event that the sender atom （or the medi-atom, for teleportation of cavity field state） is detected in the higher state. The scheme is in contrast to the previous ones of using a maximally two-particle entangled state as quantum channel.展开更多
We propose a scheme for the deterministic generation of qutrit entanglement for two atoms trapped in an optical cavity. Taking advantage of the adiabatic passage, the operation is immune to atomic spontaneous emission...We propose a scheme for the deterministic generation of qutrit entanglement for two atoms trapped in an optical cavity. Taking advantage of the adiabatic passage, the operation is immune to atomic spontaneous emission as the atomic excited states are never populated; under certain conditions, the probability that the cavity is excited is negligible. We also study the influences of the dissipation due to the atomic spontaneous emission and cavity decay.展开更多
This paper proposes an alternative scheme for generating cluster-type of entangled coherent states. This scheme is based on resonant interaction of a two-mode cavity with a two-level atom driven by strong classical fi...This paper proposes an alternative scheme for generating cluster-type of entangled coherent states. This scheme is based on resonant interaction of a two-mode cavity with a two-level atom driven by strong classical fields. Thus the required interaction time is greatly shortened, which is very important in view of decoherence.展开更多
The existence of decoherence-free subspace （DFS） has been discussed widely. In this paper, we propose an alternative scheme for generating the four-atom W states by manipulating DF qubits. The atoms are divided into...The existence of decoherence-free subspace （DFS） has been discussed widely. In this paper, we propose an alternative scheme for generating the four-atom W states by manipulating DF qubits. The atoms are divided into two pairs and trapped in two separate optical cavities. Manipulation of atoms within DFS may generate a two-atom maximally entangled state in an individual cavity, which is a stable state. After driving the system out of DFS, the atoms will interact resonantly with the cavity field. The photons leaking from the cavities interfere at the beamsplitter, which destroys which-path information, and are finally detected by one of the detectors, leading to the generation of a W state. In addition, the numerical simulation indicates that the fidelity of the prepared state can, for a very wide parameter regime, be very close to unity.展开更多
We propose a robust scheme to generate four-mode entangled states by using the method of adiabatic passage. Our scheme is more insensitive to certain practical sources of noise, such as randomness in the atom＇s posit...We propose a robust scheme to generate four-mode entangled states by using the method of adiabatic passage. Our scheme is more insensitive to certain practical sources of noise, such as randomness in the atom＇s position, atomic spontaneous emission. In addition, the Rabi frequencies of the classical field and interaction time need not to be accurately adjusted as long as the adiabatic condition is ful6lled. The 6delity for the prepared state is higher than 0.97 under current experimental parameters.展开更多
We propose a scheme for the direct measurement of Wigner function in two-mode cavity QED. The atoms are sent to resonantly interact with two orthogonally polarized cavity modes in the presence of strong classical fiel...We propose a scheme for the direct measurement of Wigner function in two-mode cavity QED. The atoms are sent to resonantly interact with two orthogonally polarized cavity modes in the presence of strong classical field. The probability of measuring the atom in the ground state directly gives the useful information of the cavity field. This method can be used for quantum non-demolition measurement of the photon number.展开更多
We propose a scheme for realizing a controlled geometric phase gate for two neutral atoms.We apply thestimulated Raman adiabatic passage to transfer atoms from their ground states into Rydberg excited states, and use ...We propose a scheme for realizing a controlled geometric phase gate for two neutral atoms.We apply thestimulated Raman adiabatic passage to transfer atoms from their ground states into Rydberg excited states, and use theRydberg interaction induced energy shifts to generate geometric phase and construct quantum gates.展开更多
This paper presents a method for generating entanglement molecules, which is introduced by Dur （2001 Phys. Rev. A）. In this scheme, N ladder-type three-level atoms are sent through a resonant weak coherent cavity fi...This paper presents a method for generating entanglement molecules, which is introduced by Dur （2001 Phys. Rev. A）. In this scheme, N ladder-type three-level atoms are sent through a resonant weak coherent cavity field, then the system states are measured. And the system field may collapse onto some possible types of entanglement molecules. Meanwhile it discusses about the interaction time from the experimental point of view, and compare the result with the previous scheme proposed by Huang （2004 J. Phys. B： At. Mol. Opt. Phys.）.展开更多
In the context of microwave cavity QED, this paper proposes a new scheme for teleportation of an arbitrary pure state of two atoms. The scheme is very different from the previous ones which achieve the integrated stat...In the context of microwave cavity QED, this paper proposes a new scheme for teleportation of an arbitrary pure state of two atoms. The scheme is very different from the previous ones which achieve the integrated state measurement, it deals in a probabilistic but simplified way. In the scheme, no additional atoms are involved and thus only two atoms are required to be detected. The scheme can also be used for the teleportation of arbitrary pure states of many atoms or two-mode cavities.展开更多
A scheme is proposed for generating entangled W states with four cavity modes. In this scheme, we send a V-type three-level atom through two identical two-mode cavities in succession. After the atom exits from the sec...A scheme is proposed for generating entangled W states with four cavity modes. In this scheme, we send a V-type three-level atom through two identical two-mode cavities in succession. After the atom exits from the second cavity, the four cavity modes are prepared in the W state. On the other hand we can obtain three-atom W states by sending three V-type three-level atoms through a two-mode cavity in turn. The present scheme does not require conditional measurement, and it is easily generalized to preparing 2n-mode W states and n-atom W states.展开更多
We propose a scheme for preparing four-particle Greenberger-Horne-Zeilinger states using two identical bimodal cavities, each supports two modes with different frequencies. This scheme is an alternative to another pub...We propose a scheme for preparing four-particle Greenberger-Horne-Zeilinger states using two identical bimodal cavities, each supports two modes with different frequencies. This scheme is an alternative to another published work [Christopher C Gerry 1996 Phys. Rev. A 53 4591]. Comparisons between them are discussed. The fidelity and the probability of success influenced by cavity decay for the generated states are also considered.展开更多
We investigate the effect of the dipole–dipole interaction(DDI) on the photon statistics with two atoms trapped in an optical cavity driven by a laser field and subjected to cooperative emission. By means of the quan...We investigate the effect of the dipole–dipole interaction(DDI) on the photon statistics with two atoms trapped in an optical cavity driven by a laser field and subjected to cooperative emission. By means of the quantum trajectory analysis and the second-order correlation functions, we show that the photon statistics of the cavity transmission can be flexibly modulated by the DDI while the incoming coherent laser selectively excites the atom–cavity system’s nonlinear Jaynes–Cummings ladder of excited states. Finally, we find that the effect of the cooperatively atomic emission can also be revealed by the numerical simulations and can be explained with a simplified picture. The DDI induced nonlinearity gives rise to highly nonclassical photon emission from the cavity that is significant for quantum information processing and quantum communication.展开更多
We propose to deterministically realize the qutrit-qutrit maximal entanglement for two atoms held in separate cavities coupled by an optical resonator. We study such a system in the resonant regime and show that the l...We propose to deterministically realize the qutrit-qutrit maximal entanglement for two atoms held in separate cavities coupled by an optical resonator. We study such a system in the resonant regime and show that the laser-driven resonant dynamics allow for the fast and robust creation of qutrit-qutrit entanglement.展开更多
基金Project supported by the National Natural Science Foundation of China （Grant No 10225421）.
文摘An alternative scheme is presented for teleportation of a two-atom entangled state in cavity quantum electrodynamics （QED）. It is based on the resonant atom-cavity field interaction. In the scheme, only one cavity is involved, and the number of the atoms needed to be detected is decreased compared with the previous scheme. Since the resonant atom-cavity field interaction greatly reduces the interaction time, the decoherence effect can be effectively suppressed during the teleportation process. The experimental feasibility of the scheme is discussed. The scheme can easily be generalized to the teleportation of N-atom Greeninger-Horne-Zeilinger （GHZ） entangled states. The number of atoms needed to be detected does not increase as the number of the atoms in the GHZ state increases.
基金Supported by the National Natural Science Foundation of China under Grant No 10674025, and the Key Laboratory of Quantum Information of University of Science and Technology of China.
文摘We propose a scheme to prepare many two-mode cavities into one-dimensional cluster states in the context of cavity QED. The left-circularly polarized state and right-circularly polarized state of the cavity are encoded as the logic zero and one of the qubits. In the scheme, the atomic spontaneous emission is suppressed, and the fidelity is unaffected by the cavity decay on the assumption that the detection efficiencies of all the photondetectors are 1.
基金supported by the National Natural Science Foundation of China (Grant No. 10974028)the Doctoral Foundation of the Ministry of Education of China (Grant No. 20093514110009)+3 种基金the Natural Science Foundation of Fujian Province of China (Grant No. 2009J06002)the Fund from Fuzhou University (Grant No. 022408)the National Basic Research Program of China (Grant Nos. 2011CB921200 and 2011CBA00200)the China Postdoctoral Science Foundation (Grant No. 20110490828)
文摘The quantum swap gate is one of the most useful gates for quantum computation. Two-qubit entanglement and a controlled-NOT quantum gate in a neutral Rydberg atom system have been achieved in recent experiments. It is therefore very interesting to propose a scheme here for swapping a quantum state between two trapped neutral atoms via the Rydberg blockade mechanism. The atoms interact with a sequence of laser pulses without individual addressing. The errors of the swap gate due to imprecision of pulse length, finite Rydberg interaction, and atomic spontaneous emission are discussed.
基金Project supported by the National Natural Science Foundation of China （Grant No 10674025）, the Key Laboratory of Quantum Information of University of Science and Technology of China, the National Natural Science Foundation of Fujian Province of China （Grant No 2006J0235）, and Foundation of the Education Department of Fujian Province, China （Grant No JB06033）.
文摘This paper shows that, based on the single-photon JC model depicting the resonant interaction of a two-level atom with a single cavity mode, an unknown atomic state and cavity photon superposition state can be faithfully telcported with only a single measurement. The scheme is probabilistie, its success lies on the event that the sender atom （or the medi-atom, for teleportation of cavity field state） is detected in the higher state. The scheme is in contrast to the previous ones of using a maximally two-particle entangled state as quantum channel.
基金supported by the National Natural Science Foundation of China (Grant Nos.10674025 and 10974028)the Fujian Natural Science Foundation of China (Grant No.2009J06002)+2 种基金the Doctoral Foundation of the Ministry of Education of China(Grant Nos.20070386002 and 20093514110009)the Funds from State Key Laboratory Breeding Base of Photocatalysis,Fuzhou Universitythe Funds from the Education Department of Fujian Province of China (Grant No.JB08010)
文摘We propose a scheme for the deterministic generation of qutrit entanglement for two atoms trapped in an optical cavity. Taking advantage of the adiabatic passage, the operation is immune to atomic spontaneous emission as the atomic excited states are never populated; under certain conditions, the probability that the cavity is excited is negligible. We also study the influences of the dissipation due to the atomic spontaneous emission and cavity decay.
基金Project partly supported by the National Natural Science Foundation of China (Grant Nos 10575119 and 10235030)
文摘This paper proposes an alternative scheme for generating cluster-type of entangled coherent states. This scheme is based on resonant interaction of a two-mode cavity with a two-level atom driven by strong classical fields. Thus the required interaction time is greatly shortened, which is very important in view of decoherence.
文摘The existence of decoherence-free subspace （DFS） has been discussed widely. In this paper, we propose an alternative scheme for generating the four-atom W states by manipulating DF qubits. The atoms are divided into two pairs and trapped in two separate optical cavities. Manipulation of atoms within DFS may generate a two-atom maximally entangled state in an individual cavity, which is a stable state. After driving the system out of DFS, the atoms will interact resonantly with the cavity field. The photons leaking from the cavities interfere at the beamsplitter, which destroys which-path information, and are finally detected by one of the detectors, leading to the generation of a W state. In addition, the numerical simulation indicates that the fidelity of the prepared state can, for a very wide parameter regime, be very close to unity.
基金Supported by the National Natural Science Foundation of China under Grant No 10674025, and the Key Laboratory of Quantum Information of University of Science and Technology of China.
文摘We propose a robust scheme to generate four-mode entangled states by using the method of adiabatic passage. Our scheme is more insensitive to certain practical sources of noise, such as randomness in the atom＇s position, atomic spontaneous emission. In addition, the Rabi frequencies of the classical field and interaction time need not to be accurately adjusted as long as the adiabatic condition is ful6lled. The 6delity for the prepared state is higher than 0.97 under current experimental parameters.
基金Project supported by the National Natural Science Foundation of China(Grant No.10974028)the Doctoral Foundation of the Ministry of Education of China(Grant No.20093514110009)+1 种基金the Natural Science Foundation of Fujian Province of China(Grant No.2009J06002)the Funds from the State Key Laboratory Breeding Base of Photocatalysis,Fuzhou University
文摘We propose a scheme for the direct measurement of Wigner function in two-mode cavity QED. The atoms are sent to resonantly interact with two orthogonally polarized cavity modes in the presence of strong classical field. The probability of measuring the atom in the ground state directly gives the useful information of the cavity field. This method can be used for quantum non-demolition measurement of the photon number.
基金Supported by the National Natural Science Foundation of China under Grant No.10974028 the Doctoral Foundation of the Ministry of Education of China under Grant No.20093514110009+1 种基金 the Natural Science Foundation of Fujian Province under Grant No.2009J06002Funds from the State Key Laboratory Breeding Base of Photocatalysis,Fuzhou University
文摘We propose a scheme for realizing a controlled geometric phase gate for two neutral atoms.We apply thestimulated Raman adiabatic passage to transfer atoms from their ground states into Rydberg excited states, and use theRydberg interaction induced energy shifts to generate geometric phase and construct quantum gates.
基金supported by the Natural Science Foundation of Fujian Province of China (Grant No T0650007)Funds from Education Department of Fujian Province of China (Grant No JB06041)
文摘This paper presents a method for generating entanglement molecules, which is introduced by Dur （2001 Phys. Rev. A）. In this scheme, N ladder-type three-level atoms are sent through a resonant weak coherent cavity field, then the system states are measured. And the system field may collapse onto some possible types of entanglement molecules. Meanwhile it discusses about the interaction time from the experimental point of view, and compare the result with the previous scheme proposed by Huang （2004 J. Phys. B： At. Mol. Opt. Phys.）.
基金Project supported by National Natural Science Foundation of China （Grant No 10674025）, and National Natural Science Foun dation of Fujian Province of China （Grant No 2006J0235）.
文摘In the context of microwave cavity QED, this paper proposes a new scheme for teleportation of an arbitrary pure state of two atoms. The scheme is very different from the previous ones which achieve the integrated state measurement, it deals in a probabilistic but simplified way. In the scheme, no additional atoms are involved and thus only two atoms are required to be detected. The scheme can also be used for the teleportation of arbitrary pure states of many atoms or two-mode cavities.
文摘A scheme is proposed for generating entangled W states with four cavity modes. In this scheme, we send a V-type three-level atom through two identical two-mode cavities in succession. After the atom exits from the second cavity, the four cavity modes are prepared in the W state. On the other hand we can obtain three-atom W states by sending three V-type three-level atoms through a two-mode cavity in turn. The present scheme does not require conditional measurement, and it is easily generalized to preparing 2n-mode W states and n-atom W states.
基金Project supported by the National Natural Science Foundation of China （Grant Nos 10225421 and 10674025）, and the Natural Science Foundation of Fujian Province, China （Grant No 2006J0235）.
文摘We propose a scheme for preparing four-particle Greenberger-Horne-Zeilinger states using two identical bimodal cavities, each supports two modes with different frequencies. This scheme is an alternative to another published work [Christopher C Gerry 1996 Phys. Rev. A 53 4591]. Comparisons between them are discussed. The fidelity and the probability of success influenced by cavity decay for the generated states are also considered.
基金supported by the National Natural Science Foundation of China(Grant Nos.11305037,11347114,and 11374054)the Natural Science Foundation of Fujian Province,China(Grant No.2013J01012)
文摘We investigate the effect of the dipole–dipole interaction(DDI) on the photon statistics with two atoms trapped in an optical cavity driven by a laser field and subjected to cooperative emission. By means of the quantum trajectory analysis and the second-order correlation functions, we show that the photon statistics of the cavity transmission can be flexibly modulated by the DDI while the incoming coherent laser selectively excites the atom–cavity system’s nonlinear Jaynes–Cummings ladder of excited states. Finally, we find that the effect of the cooperatively atomic emission can also be revealed by the numerical simulations and can be explained with a simplified picture. The DDI induced nonlinearity gives rise to highly nonclassical photon emission from the cavity that is significant for quantum information processing and quantum communication.
基金Supported by the National Basic Research Program of China under Grant No 2012CB921601, the National Natural Science Foundation of China under Grant Nos 11247283, 11305037, 11347114, and 11374054, the Natural Science Foundation of Fujian Province under Grant No 2013J01012, and the Fund from Fuzhou University.
文摘We propose to deterministically realize the qutrit-qutrit maximal entanglement for two atoms held in separate cavities coupled by an optical resonator. We study such a system in the resonant regime and show that the laser-driven resonant dynamics allow for the fast and robust creation of qutrit-qutrit entanglement.
