共查询到20条相似文献,搜索用时 843 毫秒
1.
ZHENGShi-Biao LINLi-Hua JIANGYun-Kun 《理论物理通讯》2003,40(1):103-104
An efficient scheme is proposed for the generation of atomic Schroedinger cat states in an optical cavity. In the scheme N three-level atoms are loaded in the optical cavity. Raman coupling of two ground states is achieved via a laser tield and the cavity mode. The cavity mode is always in the vacuum state and the atoms have no probability of being populated in the excited state. Thus, the scheme is insensitive to both the cavity decay and spontaneous emission. 相似文献
2.
This paper proposes an efficient scheme for deterministic generation
of entangled coherent states for two atomic samples. In the scheme
two collections of atoms are trapped in an optical cavity and driven
by a classical field. Under certain conditions the two atomic
samples evolve from an coherent state to an entangled coherent
state. During the interaction the cavity mode is always in the
vacuum state and the atoms have no probability of being populated in
the excited state. Thus, the scheme is insensitive to both the
cavity decay and atomic spontaneous emission. 相似文献
3.
We propose a simple scheme to not only generate GHZ states and W states of the multiparticle but also form a new category of multiparticle entangled states by letting the λ-type three-level atoms simultaneously interacting with a coherent cavity field followed by the selective measurements on the cavity mode. We investigate the influence of the cavity dissipation on the generated entangled state and discuss the experimental feasibility of our scheme. It is shown that the intensity of the coherent cavity field plays an instructive role in contribution to state preparation process while the cavity decay and the detuning between the atoms and cavity mode result in the deterioration of the generated entangled state. 相似文献
4.
Realization of Three-Qubit Controlled-Phase Gate Operation with Atoms in Cavity QED System 总被引:2,自引:0,他引:2 下载免费PDF全文
We propose a scheme for realization of three-qubit controlled-phase gate via passing two three-level atoms through a high-Q optical cavity in a cavity QED system. In the presented protocol, the two stable ground states of the atoms act as the two controlling qubits and the zero- and one-photon Fock states of the cavity-field form the target qubit, and no auxiliary state or any measurement is required. The numerical simulation shows that the gate fidelities remain at a high level under the influence of the atomic spontaneous emission, the decay of the cavity mode and deviation of the coupling strength. The experimental feasibility of our proposal is also discussed. 相似文献
5.
We propose a scheme for conditional quantum logic between two 3-state atoms that share a quantum data bus such as a single mode optical field in cavity QED systems, or a collective vibrational state of trapped ions. Making use of quantum interference, our scheme achieves successful conditional phase evolution without any real transitions of atomic internal states or populating the quantum data bus. In addition, it requires only common addressing of the two atoms by external laser fields. 相似文献
6.
A scheme is presented for generating entangled states of multiple
atoms in a cavity. In the scheme the atoms simultaneously interact
with a cavity mode, with the first atom driven by two classical
fields and the other atoms driven by a classical field. Our scheme
is valid even if the cavity decay rate is larger than the effective
coupling strength, which is important for experiment. The generation
of entangled states is conditional on the detection of a photon
decaying from the cavity and thus the fidelity of the entangled
state is insensitive to the detection inefficiency. Furthermore, the
scheme can be applied to the case with any number of atoms in
principle. 相似文献
7.
A robust scheme is presented for realizing entangled states for two atoms trapped in separate cavities connected by an optical fiber. The first atom is initially in a superposition of the excited state and an auxiliary ground state not coupled to the first cavity, while the second one is initially in the ground state coupled to the second cavity. The scheme involves two atom-cavity-fiber interactions accompanied by the monitoring of the cavity decay and atomic spontaneous emission. The two atoms evolve to an entangled state through exchanging an excitation after the first interaction. The states with the excitation failing to be transferred are eliminated when a photon is detected during the second interaction. Therefore, the scheme is insensitive to the decoherence effect and detection inefficiency. 相似文献
8.
Zhi-Rong Zhong 《Optics Communications》2010,283(1):189-191
We present a scheme for realizing a multi-atom NOON state via cavity QED system. The scheme bases on the Jaynes-Cumming mode with collective atomic bosonic mode. In the process, a series of control atoms are sent through two single mode cavities which are initially in vacuum states and have the same collective atoms. After the suitable interaction time, the collective atoms in two cavities are in the desired state. 相似文献
9.
A Feasible Scheme for Teleportation of Multi-atom Cat-like States in Thermal Cavities 总被引:4,自引:0,他引:4
An experimentally feasible scheme for implementing teleportation of multi-atom cat-like states in cavity QED is proposed. In the scheme the atoms interact simultaneously with a highly detuned cavity mode and are driven by a strong classical field, and the atomic state evolution is independent of cavity field state. Thus the scheme is insensitive to both the cavity decay and the thermal field, which is of importance from the experimental point of view. All the orthogonal and complete multi-atom GHZ states can be exactly distinguished only by one step, so our scheme can also be used for other purposes such as dense coding using multi-atom GHZ states as quantum channels. 相似文献
10.
利用简并Λ型三能级原子与单模腔场的Raman相互作用制备压缩态的叠加态 总被引:4,自引:1,他引:3
本文提出利用简并Λ型三能级原子与单模腔场的Raman相互作用制备压缩相干态的叠加态的一种新方案,并对单模压缩相干态光场中有关压缩角(即压缩方向)的控制问题进行了详细讨论. 相似文献
11.
Generation of any superposition of coherent states along a straight line via resonant atom-cavity interaction 下载免费PDF全文
This paper proposes a scheme for generating arbitrary
superpositions of several coherent states along a straight line for
a cavity mode. In the scheme, several atoms are sent through a
cavity initially in a strong coherent state. The superposition of
several coherent states with desired coefficients may be generated
if each atom is detected in the excited state after it exits the
cavity. The scheme is based on resonant atom--cavity interaction and
no classical field is required during and after the atom--cavity
interaction. Thus, the scheme is very simple and the interaction
time is very short, which is important in view of decoherence. 相似文献
12.
XUE-PING ZANG MING YANG CHAO-QUN DU MIN WANG SHU-DONG FANG ZHUO-LIANG CAO 《Pramana》2016,86(5):1009-1019
We present two schemes for transforming bipartite non-maximally entangled states into a W state in cavity QED system, by using highly detuned interactions and the resonant interactions between two-level atoms and a single-mode cavity field. A tri-atom W state can be generated by adjusting the interaction times between atoms and the cavity mode. These schemes demonstrate that two bipartite non-maximally entangled states can be merged into a maximally entangled W state. So the scheme can, in some sense, be regarded as an entanglement concentration process. The experimental feasibility of the schemes is also discussed. 相似文献
13.
We propose a scheme for implementing a measurement of GHZ entanglement for a multipartite system via cavity QED. In the scheme the atoms interact simultaneously with a highly detuned cavity mode with the assistant of a classical field. The scheme is insensitive to the cavity decay and the thermal field. A set of GHZ states can be exactly distinguished via detecting atomic state in a simple way. 相似文献
14.
A scheme is proposed for generating NOON states for two atomic samples trapped in two distant cavities connected by a third
cavity and optical fibers. In the scheme, all the atoms are always populated in the two degenerate ground states, so the atoms’
spontaneous emission can be omitted approximately. During the operation neither the cavity modes nor fiber modes are excited,
which is important in view of decoherence. The scheme does not include projective measurement and the NOON state is generated
deterministically. 相似文献
15.
One-step generation of qutrit entanglement via adiabatic passage in cavity quantum electrodynamics 下载免费PDF全文
A scheme is proposed for generating a three-dimensional entangled state for two atoms trapped in a cavity by one step via adiabatic passage. In the scheme, the two atoms are always in ground states and the field mode of the cavity excited is negligible under a certain condition. Therefore, the scheme is very robust against decoherence. Furthermore, it needs neither the exact control of all parameters nor the accurate control of the interaction time. It is shown that qutrit entanglement can be generated with a high fidelity. 相似文献
16.
Shi-Biao Zheng 《Optics Communications》2007,278(2):345-349
We propose an efficient scheme for realizing squeezing for a cavity mode. In the scheme, a collection of ladder-type three-level atoms are trapped in a cavity and driven by two classical fields. Under certain conditions, the cavity field deterministically evolves to a squeezed state. The scheme can also be used for conditional generation of superpositions of different squeezed vacuum states. 相似文献
17.
We propose a scheme for generating maximally GHZ state for four atoms trapped in a two-mode optical cavity via combination of cavity QED and linear optics system. The GHZ state can be not only generated deterministically with a single resonant interaction in cavity QED, but also can be prepared probabilistically based on cavity QED and linear optics elements. The fidelity of the entangled states is not affected by the atomic spontaneous, cavity decay, and imperfection of the photon-detectors. Finally, we briefly analyze and discuss the experimental feasibility of the proposed scheme. 相似文献
18.
This paper proposes a scheme for generation of superpositions of
coherent states of the effective bosonic mode in a collection of
atoms. In the scheme an atomic sample interacts with a slightly
detuned cavity mode and a resonant strong classical field. Under
certain conditions the atomic system evolves from a coherent state
to a superposition of coherent states. 相似文献
19.
Ju-Mei Chen Lin-Mei Liang Cheng-Zu Li Ping-Xing Chen Hong-Yi Dai 《Optics Communications》2009,282(15):3181-3184
A scheme is proposed to implement distributed quantum computation in decoherence-free subspaces (DFSs) via adiabatic passage. The logical single-qubit is encoded in two atoms trapped in a single-mode cavity and the cavities are connected by an optical fiber. Our scheme is immune from the decoherence due to dephasing in virtue of encoding scheme and the decoherence due to spontaneous emission from excited states as the system in our scheme evolves along a dark state. Furthermore, the decoherence due to photon decay is greatly suppressed since the fiber mode remains in a vacuum state and the populations of the cavities’ modes being excited can be negligible under certain condition. It is shown that the minimum fidelity of the resultant gate operation for an arbitrary input state could be over 0.97. 相似文献