共查询到20条相似文献,搜索用时 15 毫秒
1.
Scheme for Concentration of Unknown Greeberger-Horne-Zeilinger Entangled States via Cavity Decay 下载免费PDF全文
We present a scheme for entanglement concentration of an unknown atomic non-maximally entangled GHZ state via cavity decay. In the scheme, the atom trapped in a cavity is manipulated by laser field, so the maximally entangled GHZ state can be obtained by performing certain operation, which can be realized by illuminating the atom in a cavity. Our method is robust against spontaneous atomic decay. 相似文献
2.
Zong-Liang Liu Shao-Hua Li Chang-Yong Chen 《International Journal of Theoretical Physics》2009,48(8):2365-2371
A scheme for approximate and conditional teleportation of an unknown atomic state via dissipative two-photon interaction in
cavity QED is proposed. In our scheme, the dissipative two-photon interaction Jaynes-Cummings model is used to realize the
approximate and conditional teleportation. We investigate analytically the influence of the cavity mode decay on the teleportation
fidelity and show that the high fidelity teleportation can be implemented in dissipative case. Our scheme does not involve
the Bell-state measurement and an additional atom, only requiring two atoms and one single-mode cavity. The scheme may be
generalized to not only the teleportation of the state of a cavity mode to another mode by means of a single atom but also
the teleportation of the state of a trapped ion. 相似文献
3.
ZHENG Shi-Biao 《理论物理通讯》2006,46(4):613-616
We propose a scheme to teleport a superposition of three states of an atom trapped in a cavity to a second atom trapped in a remote cavity. The scheme is based on the detection of photons leaking from the cavities after the atom-cavity interaction. 相似文献
4.
ZHENG Shi-Biao 《理论物理通讯》2006,46(10)
We propose a scheme to teleport a superposition of three states of an atom trapped in a cavity to a second atom trapped in a remote cavity. The scheme is based on the detection of photons leaking from the cavities after the atom-cavity interaction. 相似文献
5.
We propose a scheme for information concentration of three remote two-level atoms in cavity QED. Our scheme does not involve the Bell-state measurement. During the interaction between atom and cavity, the cavity frequency is largely detuned from the atomic transition frequency, thus the scheme is insensitive to both the cavity decay and the thermal field. The idea can also be used to realize the remote information concentration of trapped ions. 相似文献
6.
We propose an optical scheme to generate cluster states of atomic qubits, with each trapped in separate optical cavity, via atom-cavity-laser interaction. The quantum information of each qubit is encoded on the degenerate ground states of the atom, hence the entanglement between them is relatively stable against spontaneous emission. A single-photon source and two classical fields are employed in the present scheme. By controlling the sequence and time of atom-cavity-laser interaction, we show that the atomic cluster states can be produced deterministically. 相似文献
7.
A simple scheme is proposed to generate the W state of N Λ-type neutral atoms trapped in an optical cavity via Raman transition. Conditional on no photon leakage from the cavity, the N-qubit W state can be prepared perfectly by turning on a classical coupling field for an appropriate time. Compared with the previous ones, our scheme requires neither individual laser addressing of the atoms, nor demand for controlling N atoms to go through an optical cavity simultaneously with a constant velocity. We investigate the influence of cavity decay using the quantum jump approach and show that the preparation time decreases and the success probability increases with atom number because of a collective enhancement of the coupling. 相似文献
8.
Jing Wu 《Optics Communications》2011,284(7):2083-2088
We proposed a simple scheme to deterministically generate three-dimensional (3D) quantum state transfer (QST) between two spatially atoms based on the selectivity photon emission and absorption progresses. In the present scheme, two M-type five-level atoms are trapped into two cavities connected by a fiber. By quantitatively discussing the evolution of system, we show that the effects of atom's spontaneous decay and photon leakage out of fiber can be suppressed in our scheme due to the presence of virtual excited processes in atom and fiber modes. Moreover, we also show that the present scheme can be extended to realize QST between distant nodes in a coupled array of optical cavity, which is very useful for the progress of the quantum information network. 相似文献
9.
We present a scheme to prepare an optical “quantum switch”, a superposition of “open” and “closed” states. The scheme is based on the interaction of an Λ-type three-level atom with a single-mode of quantized cavity field and an external classical driving field, in the regime where the atom and fields are highly detuned. We show how this interaction can be used to generate coherent states of the cavity field in contrast to the usual method used in microwave cavity QED of injecting a coherent state into a cavity. A combination of switches could be used to prepare a quantum superposition of coherent field states located simultaneously in two cavities. Compared with previous proposals, our scheme is simplified due to economizes the Ramsey zone and the time required for the state generation is short. 相似文献
10.
We propose a scheme for long-distance quantum state transfer between different atoms based on cavity-assisted interactions. In our scheme, a coherent optical pulse sequentially interacts with two distant atoms trapped in separated cavities. Through the measurement of the state of the first atom and the homodyne detection of the final output coherent light, the quantum state can be transferred into the second atom with a success probability of unity and a fidelity of unity. In addition, our scheme neither requires the high-Q cavity working in the strong coupling regime nor employs the single-photon quantum channel, which greatly relaxes the experimental requirements. 相似文献
11.
12.
Quantum state engineering by superpositions of coherent states along a straight line with a single atomic state measurement 总被引:1,自引:0,他引:1
A new scheme is proposed for preparation of a type of nonclassical state in cavity QED. In the scheme, an atom either flying through or trapped within a cavity, is controlled by the classical Stark effect; this makes it interact alternately with a (resonant) classical field and with the (dispersive) cavity field. The cavity field, which allows an arbitrary displacement operation during the process, after the detection on the atom, finally collapses to the specific superpositions of coherent states, with their weighting factors controllable. The scheme is also applied for preparation of superpositions of motional coherent states for a trapped ion. The scheme is in contrast to all the previous ones, and thus provides a new perspective for quantum state engineering. 相似文献
13.
Dao-Ming Lu 《International Journal of Theoretical Physics》2012,51(7):2119-2126
Three two-level atoms are trapped in two initially empty cavities connected by an optical fiber. The entanglement evolution between two atoms in the same cavity and the entanglement evolution between two cavities are investigated. The influence of the state-selective measurement of the atom trapped in the other cavity on the entanglement and that of fiber-cavity coupling coefficient on the entanglement are discussed. The results obtained show that atom-atom entanglement property is strengthened, and cavity-cavity entanglement property is weakened with increasing of the cavity-fiber coupling coefficient. On the other hand, the results also show that the entanglement between two cavities and that between two atoms in the same cavity can be strengthened through the state-selective measurement on the atom trapped in the other cavity. 相似文献
14.
15.
We propose a scheme for preparing the squeezing of an atomic motion and an Einstein-Podolsky-Rosen state in position and momentum of a pair of distantly separated trapped atoms. The scheme utilizes the quantum nondemolition measurements with interaction between the cavity field and the motional state of the trapped atom in cavity QED. By illuminating the atoms with bichromatic light, the interaction Hamiltonian of the cross-Kerr effect between the cavity and atomic motion is generated to implement quantum nondemolition measurements.Received: 5 February 2003, Published online: 17 July 2003PACS:
03.67.Hk Quantum communication - 32.80.Lg Mechanical effects of light on atoms, molecules, and ions - 42.50.-p Quantum optics 相似文献
16.
Possible Realization of Cluster States and Quantum Information Transfer in Cavity QED via Raman Transition 下载免费PDF全文
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. 相似文献
17.
We investigate the generation and the evolution of continuous-variable (CV) entanglement from a laser-driven four-state atom inside a doubly resonant cavity under Raman excitation. Two transitions in the four-state atom independently interact with the two cavity modes, while two other transitions are driven by coupling laser fields. By including the atomic relaxation as well as cavity losses, we show that the CV entanglement with large mean number of
photons can be generated in our scheme. We also show that the intensity of the coupling laser fields can influence effectively the entanglement period of the cavity field. Different from the conventional resonant excitation scheme where zero one-photon detuning are required, it is found that the intensity and period of entanglement between the two cavity modes as well as the total mean photon number of the cavity field can be adjusted by properly
modulating the frequency detuning. 相似文献
18.
We study atomic state transfer and entanglement generation when the N atomic ensemble is trapped in two coupled cavities. We show that based on the collective interaction between the atoms and
local cavity fields an ideal quantum state transfer can be realized if some special conditions are satisfied. In addition,
the maximal atom entangled state can be achieved. The effect of the cavity losses on the quantum processes is also studied. 相似文献
19.
Boca A Miller R Birnbaum KM Boozer AD McKeever J Kimble HJ 《Physical review letters》2004,93(23):233603
The transmission spectrum for one atom strongly coupled to the field of a high finesse optical resonator is observed to exhibit a clearly resolved vacuum Rabi splitting characteristic of the normal modes in the eigenvalue spectrum of the atom-cavity system. A new Raman scheme for cooling atomic motion along the cavity axis enables a complete spectrum to be recorded for an individual atom trapped within the cavity mode, in contrast to all previous measurements in cavity QED that have required averaging over 10(3)-10(5) atoms. 相似文献
20.
We propose an efficient scheme for realizing two-mode squeezing for two cavity modes with an atomic ensemble trapped in the cavity and driven by two classical fields. Through a suitable choice of the driving classical fields, the evolution dynamics of the two cavity modes is decoupled with the atomic system and described by a two-mode squeezing operator. We show that a highly squeezed state can be obtained at the output even with a bad cavity. The required experimental techniques are within the scope of what can be obtained in the BEG-cavity setup. 相似文献