共查询到20条相似文献,搜索用时 46 毫秒
1.
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
2.
A scheme for generating cluster states via Raman interaction is proposed. In the scheme, we firstly prepare cluster states of multi-cavities with information encoded in the coherent states and then generate cluster states of multiatoms, which encode the information in the ground states of A-type atoms. The advantages of our scheme are that the atomic spontaneous radiation can be efficiently reduced since the cavity frequency is largely detuned from the atomic transition frequency and the Hadamard gate operation of the coherent states is replaced by measuring the coherent states. 相似文献
3.
We propose two schemes for the generation of cluster states in the context of cavity quantum electrodynamics (QED). In the first scheme, we prepare multi-cavity cluster states with information encoded in the coherent states. The second scheme is to generate multi-atom cluster states, where qubits axe represented by the states of cascade Rydberg atoms. Both the schemes axe based on the atom-cavity interaction and the atomic spontaneous radiation can be efficiently reduced since the cavity frequency is largely detuned from the atomic transition frequency. 相似文献
4.
This paper presents a scheme for implementing a Fredkin gate on
three modes of a cavity. The scheme is based on the dispersive
atom-cavity interaction. By modulating the cavity frequency and the
atomic transition frequency appropriately, it obtains the effective
form of nonlinear interaction between photons in the three-mode
cavity. This availability is testified via numerical analysis. It
also considers both the situations with and without dissipation. 相似文献
5.
This paper presents a scheme for realizing the frequency
up-conversion between two collective atomic modes. In the scheme two
atomic samples are coupled to a cavity mode. Under the large
detuning condition, the two collective atomic modes are coupled via
the virtual excitation of the cavity mode and the effective
Hamiltonian corresponds to the frequency up-conversion. In the
scheme the cavity mode is only virtually excited and thus the
process is insensitive to cavity decay. 相似文献
6.
Quantum entangled states, especially those having particular properties, are key resources for quantum information and quantum computation. In this paper, we put forward a new scheme to produce 31 continuous–variable(CV) tripartite entanglement fields based on three optical frequency combs via cascade nonlinear processes in an optical parametric cavity,and investigate the spectral characteristics of three frequency combs. The center wavelengths of the three combs are designed as 852 nm, 780 nm(atomic transition lines), and 1550 nm(fiber communication wavelength). The positivity under partial transposition(PPT) criterion, which is sufficient and necessary, is used to evaluate the entanglement in each group of comb lines. This scheme is experimentally feasible and valuable for constructing quantum information networks in future. 相似文献
7.
A scheme for transferring an unknown atomic entangledstate via cavity quantum electrodynamics 下载免费PDF全文
In this paper, we propose a scheme for transferring an unknown atomic entangled
state via cavity quantum electrodynamics (QED). This scheme, which has a successful
probability of 100 percent, does not require Bell-state measurement and performing
any operations to reconstruct an initial state. Meanwhile, the scheme only involves
atom--field interaction with a large detuning and does not require the transfer of
quantum information between the atoms and cavity. Thus the scheme is insensitive to
the cavity field states and cavity decay. This scheme can also be extended to
transfer ring an entangled state of $n$-atom. 相似文献
8.
This paper proposes a simple scheme for generating a three-atom GHZ
state via cavity quantum electrodynamics (QED). The task can be
achieved through the interaction between two EPR states, which can be
prepared easily with current technology. In this scheme, the cavity
field is only virtually excited during the interaction process, and
no quantum information transfer between the atoms and the cavity is
required. Thus it greatly prolongs the efficient decoherent time.
Moreover, this scheme is also applicable for generating an N-atom
GHZ state. 相似文献
9.
This paper proposes a simple scheme to generate a
four-atom entangled cluster state in cavity quantum electrodynamics.
With the assistantce of a strong classical field the cavity is only
virtually excited and no quantum information will be transferred
from the atoms to the cavity during the preparation for a four-atom
entangled cluster state, and thus the scheme is insensitive to the
cavity field states and cavity decay. Assuming that deviation of
laser intensity is 0.01 and that of simultaneity for the interaction
is 0.01, it shows that the fidelity of the resulting four-atom
entangled cluster state is about 0.9886. The scheme can also be
used to generate a four-ion entangled cluster state in a hot
trapped-ion system. Assuming that deviation of laser intensity is
0.01, it shows that the fidelity of the resulting four-ion entangled
cluster state is about 0.9990. Experimental feasibility for
achieving this scheme is also discussed. 相似文献
10.
用于提高种子注入Nd:YAG激光器性能的一种光学补偿方法的设计计算 总被引:1,自引:0,他引:1
分析了利用干涉法实现腔模锁定的种子激光器的工作原理,在此基础上提出了偏转检测器法补偿由于信号处理可引起的滞后,为种子注入激光器的腔模锁定技术的提供了新的改进方法,可方便而有效地控制从振荡器的输出光质。 相似文献
11.
ZHAN Zhi-Ming 《理论物理通讯》2009,51(1):135-138
In this paper, a theoretical scheme is proposed to implement the Deutsch-Jozsa algorithm with SQUIDs (superconducting quantum-interference devices) in cavity via Raman transition. The scheme only requires a quantized cavity field and classical microwave pulses. In this scheme, no transfer of quantum information between the SQUIDs and the cavity is required, the cavity field is only virtually excited and thus the cavity decay is suppressed. 相似文献
12.
13.
We present a scheme for the generation of a five-atom cluster state in cavity QED. During the preparation no quantum information is transferred from the atoms to the cavity, and thus the scheme is insensitive to the cavity field states and cavity decay. 相似文献
14.
We presented a scheme to implement SWAP gate in a microwave cavity. In our scheme, two superconducting quantum interference
device (SQUID) qubits are coupled to a single-mode microwave cavity field by adiabatic passage method for their manipulation.
This process of implementing SWAP gate is in the range of present experiments. The scheme can be easily obtained only by three
steps, which does not require perform any operation. In the scheme, the operations only involve three lowest flux states of
the SQUIDs, and the excited states would not be excited; therefore, the decoherence due to spontaneous emission of the SQUIDs’
levels would not affect the operations. In addition, during the whole procedure the cavity field is not necessary to be excited
because it does not require transfer quantum information between the SQUID’s and the cavity field. Thus, the cavity decay
is suppressed. Therefore our scheme may be realized in superconducting systems. 相似文献
15.
利用双光子过程耦合腔系统实现量子信息转移 总被引:2,自引:1,他引:1
给出了利用两个二能级原子和耦合腔双光子过程相互作用系统实现量子信息转移的方案。该方案中二能级原子通过双光子跃迁与单模腔场发生共振相互作用。通过控制原子与光场的相互作用时间,实现量子信息从一个原子转移到另一个原子。 相似文献
16.
JIANG Chun-Lei FANG Mao-Fa 《理论物理通讯》2007,47(3):557-560
We propose a scheme for generating maximally entangled states for two or more two-level atoms in a thermal cavity. The cavity frequency is large-detuned from the atomic transition frequency, so the Hamiltonian can be expressed as an effective form. The photon-number-dependent parts in the effective Hamiltonian are cancelled with the assistance of a strong classical field, thus the scheme is insensitive to both the cavity decay and the thermal field. The scheme can be used to generate multi-atom Bell-state and Greenberger-Horne-Zeiliner (GHZ) state. 相似文献
17.
An experimentally feasible scheme for implementing
four-atom quantum dense coding of an atom--cavity system
is proposed. The cavity is only virtually excited and no quantum information will be
transferred from the atoms to the cavity. Thus the scheme is
insensitive to cavity decay and the thermal field. In the
scheme, Alice can send faithfully 4 bits of classical information to
Bob by sending two qubits. Generalized Bell states can be exactly
distinguished by detecting the atomic state, and quantum dense
coding can be realized in a simple way. 相似文献
18.
We propose an experimentally feasible scheme of implementing perfect quantum dense coding with three-atom W-class state in cavity QED. In this scheme atoms interact simultaneously with a highly detuned cavity field and the cavity is only virtually excited, thus the scheme is insensitive to the cavity decay, which is very important in view of experiment. Moreover, we also propose a scheme of transmitting three bits of classical information by sending one qubit and one classical bit with 3-qubit W-class and GHZ states. 相似文献
19.
针对传统腔衰荡光谱技术浓度获取率低,提出基于双重锁定的连续波腔衰荡吸收光谱技术.通过波长调制一次谐波信号将激光器的频率锁定到C_2H_2吸收线上,同时使用PDH锁频技术将衰荡腔锁定到激光器上,从而避免了测量过程中激光器的频率漂移和腔长的抖动,使测量结果更加精确;并且,由于双重锁定,单次衰荡事件的发生率,也就是浓度信息的获取率只受衰荡时间以及重新锁定时间限制,在本试验系统中采集速率可以达到30 k Hz,可以实现对气体浓度的快速测量.为了提高信噪比,采用Kalman滤波技术,对浓度信息进行实时处理,有效抑制了噪声,根据阿伦方差分析,探测灵敏度可以达到4×10~(-9)cm~(-1)(2 s平均). 相似文献
20.
We propose a scheme for generating a maximally entangled state of two three-level superconducting quantum interference devices (SQUIDs) by using a quantized cavity field and classical microwave pluses in cavity. In this scheme, no quantum information will be transferred from the SQUIDs to the cavity since the cavity field is only virtually excited. Thus, the cavity decay is suppressed during the entanglement generation. 相似文献