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 共查询到19条相似文献,搜索用时 62 毫秒
1.
A scheme for approximately and conditionally teleporting an unknown atomic state in dissipative cavity QED is proposed. It is the extension of the scheme of [Phys. Rev. A 69 (2004) 064302], where the cavity mode decay has not been considered and only a time point of system evolution and the corresponding fidelity implementing the teleportation are given. In fact, the cavity mode decay exists really and must be delt with. In this paper, we investigate the influence from the cavity mode decay on the implementation of the approximate and conditional teleportation by means of the dissipative Jaynes Cummings model and then show the analytical expression of the fidelity of realization of the teleportation. Alternatively, our scheme does not involve an additional atom, only requiring two atoms and one single-mode cavity.  相似文献   

2.
We propose an experimentally feasible teleportation scheme with three-atom W-class state, which was first proposed by Agrawal and Pati [P. Agrawal and A. Pati, Phys. Rev. A 74 (2006) 062320 ], in cavity QED. In this scheme atoms interact simultaneously with a nonresonant cavity and there is no energy exchange between the atoms and the cavity. Thus it is insensitive to the cavity decay, which is of importance in view of experiment.  相似文献   

3.
An alternative scheme is proposed for teleportation of an unknown atomic-entangled state. The scheme is based on the resonant interaction of a two-mode cavity field with a A-type three-level atom. In contrast with the previously proposed scheme of [Commun. Theor. Phys. 47 (2007) 253], the present scheme is ascendant, since the fidelity is 1.0 in principle similarly without the Bell-state measurement. The scheme may be generalized to not only the teleportation of the cavity-mode-entangled-state but also the teleportation of the multi-atomic entangled states included in generalized GHZ states. And the scheme is experimentally feasible based on the current cavity QED technique.  相似文献   

4.
In this paper, we develop the teleportation scheme in [Zheng in Phys Rev A 69, 064302, 2004],in the sense that, we work in the strong atom-field coupling regime wherein the rotating wave approximation(RWA) is no longer valid. To achieve the purpose, a scheme consisting of a qubit interacting with a single-mode quantized field is described via the Rabi model(counter rotation terms are taken into account). Our first aim is to teleport an unknown atomic state of a qubit(which interacts with the qua...  相似文献   

5.
林秀  李洪才  杨榕灿 《中国物理》2007,16(3):624-629
We present a scheme for realizing probabilistic teleportation of an unknown N-atom state via cavity QED. This scheme requires only a nonmaximally entangled pair to be used as a quantum channel, so the requirement of entanglement is reduced. In addition, our scheme does not involve the Bell-state measurement and is insensitive to the cavity decay, which is important from the experimental point of view. If the quantum channel is a two-atom maximally entangled state, teleportation of an unknown N-atom state can be realized by a simpler scheme via cavity QED.  相似文献   

6.
汪新文  刘翔  方卯发 《中国物理》2006,15(4):676-680
We propose a scheme for teleportation of an unknown N-atom state using a two-atom entangled state within a cavity QED and show the feasibility in experiment. Our scheme does not involve the Bell-state measurement and is insensitive to the cavity decay, which is important from the experimental point of view. Another feature of the scheme is that teleporting a N-atom state just requires a small amount of entanglement (i,e. a two-atom entangled state) and less classical bits (two bits).  相似文献   

7.
陈琼  方细明 《中国物理 B》2008,17(5):1587-1592
This paper proposes a scheme to teleport an arbitrary multi-particle two-level atomic state between two parties or an arbitrary zero- and one-photon entangled state of multi-mode between two high-Q cavities in cavity QED. This scheme is based on the resonant interaction between atom and cavity and does not involve Bell-state measurement. It investigates the fidelity of this scheme and find out the case of this unity fidelity of this teleportation. Considering the practical case of the cavity decay, this paper finds that the condition of the unity fidelity is also valid and obtains the effect of the decay of the cavity on the successful probability of the teleportation.  相似文献   

8.
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.[第一段]  相似文献   

9.
章文  刘益民  刘俊  张战军 《中国物理 B》2008,17(9):3203-3208
This paper proposes a scheme for implementing the teleportation of an arbitrary unknown two-atom state by using a cluster state of four identical 2-level atoms as quantum channel in a thermal cavity. The two distinct advantages of the present scheme are: (i) The discrimination of 16 orthonormal cluster states in the standard teleportation protocol is transformed into the discrimination of single-atom states. Consequently, the discrimination difficulty of states is degraded. (ii) The scheme is insensitive to the cavity field state and the cavity decay for the thermal cavity is only virtually excited when atoms interact with it. Thus, the scheme is more feasible.  相似文献   

10.
We propose a new scheme to achieve the tripartite entanglement based on the standard criteria [Phys. Rev. A 67(2003) 052315] in a inverse-tripod atomic system. In our scheme, the atomic coherence is introduced by two microwave fields which drive the upper three levels of atom. By numerically simulating the dynamics of system, we investigate the generation and evolution of entanglement in the presence of atom and cavity decay. As a result, the present research provides an efficient approach to achieve fully tripartite entanglement with different frequencies and initial states for each entangled mode, which may have impact on the progress of multicolored multi-notes quantum information networks.  相似文献   

11.
We propose a scheme to purify entanglement of two atoms from not-too-impure entangled states by checking the parity of the two atoms through the cavity input-output process. As the parity check is made by measurement on single-photon polarization, which would not affect the entanglement of the two atoms, our scheme has the successful probability double of that in a previous well-known scheme with linear optical elements [Nature (London) 410 (2001) 1067], and is insensitive to the photon loss and the detection inefficieney. Experimental feasibility of our scheme with current technology is discussed.  相似文献   

12.
At low temperatures the configurational phase space of a macroscopic complex system (e.g., a spin-glass) of N - 10^23 interacting particles may split into an exponential number Ωs - exp(const × N) of ergodic sub-spaces (thermodynamic states). It is usually assumed that the equilibrium collective behavior of such a system is determined by its ground thermodynamic states of the minimal free-energy density, and that the equilibrium free energies follow the distribution of exponentied decay. But actually for some complex systems, the equilibrium free-energy values may follow a Gaussian distribution within an intermediate temperature range, and consequently their equilibrium properties are contributed by excited thermodynamic states. Based on this analysis, the re-weighting parameter y in the cavity approach of spin-glasses is easily understood. Depending on the free-energy distribution, the optimal y can either be equal to or be strictly less than the inverse temperature β.  相似文献   

13.
We propose a scheme to generate atomic cluster states of arbitrary configuration in the cavity quantum electrodynamics (QED) system. The process is achieved via adiabatic evolution of dark states, which only requires adiabatically increasing or decreasing Rabi frequencies of laser. Thus it allows the robust implementation of entanglement against certain types of errors. Our scheme is relatively decoherence-free in the sense that excited atomic states are never populated and excited cavity photon states can be made negligible in certain conditions.  相似文献   

14.
We consider a one-dimensional array of L identical coupled cavities, and each cavity is doped with a two-level qubit. Experimentally, it has been developed in several varieties by the newest technology. We find that the one-qubit quantum state can be perfectly transferred through the cavity array, and the entanglement between the first two qubits can also be transferred to the last two qubits. In addition, we successfully realized the entangling gate and swap gate in the coupled cavity array.  相似文献   

15.
We present a scheme to implement a one-qubit phase gate with a two-level atom crossing an optical cavity in which some identical atoms are trapped. One can conveniently acquire an arbitrary phase shift of the gate by properly choosing the number of atoms trapped in the cavity and the velocity of the atom crossing the cavity. The present scheme provides a very simple and efficient way for implementing one-qubit phase gate.  相似文献   

16.
We propose a scheme for realization a quantum Controlled-NOT gate operation using two four-level atoms through a selective atom cavity interaction in cavity quantum electrodynamics system. In our protocol, the quantum information is encoded on the stable ground states of the two atoms. During the interaction between atoms and single-mode vacuum cavity-field, the atomic spontaneous emission is negligible as the large atom-cavity detuning effectively suppresses the spontaneous decay of the atoms. The influences of the dissipation and the deviation of interaction time on fidelity and corresponding success probability of the quantum Controlled-NOT gate and the experimental feasibility of our proposal are also discussed.  相似文献   

17.
In a previous work [Commun. Theor. Phys. 45 (2006) 79] a scheme was presented for approximate and conditional teleportation of an unknown atomic state in a QED-cavity without Bell-state measurement via two-photon Jaynes-Cummings model in the effective Hamiltonian approach. This comment presents an alternative method, based on the so called "full two-photon Jaynes-Cummings Hamiltonian approach". Accordingly, it describes the evolution of the two-photon degenerate process for arbitrary average photon number inside the cavity, as the correct way to implement teleportation in this scenario.  相似文献   

18.
In this paper, we propose two physical schemes for teleporting an unknown atomic state through noisy channel in cavity QED. The quantum channel is a noisy one -- a mixed GHZ state, which is more realistic in quantum information processing. We solve analytically a master equation in the Lindblad form with (L2,z, L3,z, L4,z)-type of noise in cavity Q, ED. A comparison between the two protocols are discussed.  相似文献   

19.
An experimentally feasible scheme for teleportation of an unknown two-atom entangled state is proposed. Our scheme uses a duster state as the quantum channel, where we do not need any joint Bell-state measurement. Moreover the successful probability and fidelity of teleportation can both reach 1.0. The current scheme can be realized within the current experimental technology.  相似文献   

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