共查询到20条相似文献,搜索用时 486 毫秒
1.
We propose a scheme for implementing conditional quantum phase gates
for two four-state atoms trapped in a cavity. The two ground states
of the atoms are coupled through two Raman processes induced by the
cavity mode and two classical fields. Under certain conditions
nonresonant Raman processes lead to two-atom coupling and can
be used to produce conditional phase gates. The scheme is
insensitive to cavity decay, thermal photons, and atomic
spontaneous emission. The scheme does not require individual
addressing of the atoms. 相似文献
2.
A feasible scheme for constructing quantum logic gates is proposed on the basis of quantum switches in cavity QED. It is shown that the light field which is fed into the cavity due to the passage of an atom in a certain state can be used to manipulate the conditioned quantum logical gate. In our scheme, the quantum information is encoded in the states of Rydberg atoms and the cavity mode is not used as logical qubits or as a communicating “bus”; thus, the effect of atomic spontaneous emission can be neglected and the strict requirements for the cavity can be relaxed. 相似文献
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卢道明 《原子与分子物理学报》2012,29(6)
利用两个二能级原子和用光纤联接的两个单模光腔构成的系统,给出了实现量子态转移的方案。该方案中两个二能级原子分别处于用光纤联接的单模腔中,并同时与光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,实现量子态的转移。 相似文献
5.
卢道明 《原子与分子物理学报》2011,28(5):913-916
利用两个二能级原子和用光纤联接的两个单模光腔构成的系统,给出了实现量子态转移的方案。该方案中两个二能级原子分别处于用光纤联接的单模腔中,并同时与光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,实现量子态的转移。 相似文献
6.
S. Rebić D. Vitali C. Ottaviani P. Tombesi M. Artoni F. Cataliotti R. Corbalan 《Optics and Spectroscopy》2005,99(2):264-269
We present the quantum theory of a polarization phase gate that can be realized in a sample of ultracold rubidium atoms driven into a tripod configuration. The main advantages of this scheme are its relative simplicity and inherent symmetry. It is shown that conditional phase shifts of order π can be attained. 相似文献
7.
Resonant scheme for realizing quantum phase gates for two separate atoms via coupled cavities 总被引:1,自引:0,他引:1
We propose a scheme for realizing conditional quantum phase gates for two atoms that are distributed in two coupled cavities. Due to the resonant interaction in temporal evolution of the entire system, the gate operation time is greatly reduced as compared with that of the nonresonant schemes. We study the influence of imperfections in the interaction and the effect of decoherence and find the gate to be robust. We discuss the issue related to the practical implementation and show that the gate is accessible within the current cavity QED technology. 相似文献
8.
Quantum controlled phase gate and cluster states
generation via two superconducting quantum interference devices in a
cavity 总被引:3,自引:0,他引:3
Z.-Y. Xue G. Zhang P. Dong Y.-M. Yi Z.-L. Cao 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,52(3):333-336
A scheme for implementing 2-qubit quantum controlled phase gate (QCPG) is proposed with two superconducting quantum interference
devices (SQUIDs) in a cavity. The gate operations are
realized within the two lower flux states of the SQUIDs by using a quantized cavity field and classical microwave pulses.
Our scheme is achieved without any type of measurement, does not use the cavity mode as the data bus and only requires a very
short resonant interaction of the SQUID-cavity system. As an application of the QCPG operation, we also propose a scheme for
generating the cluster
states of many SQUIDs. 相似文献
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基于多粒子纠缠态在证明量子非定域性和量子信息处理方面的重要应用,提出一种方案隐形传送未知原子纠缠态.方案基于Λ型三能级原子与单模腔场的简并Raman相互作用.首先让n个原子相继通过一个相干腔场来制备量子通道.然后发送者让携带未知纠缠态的另n个原子相继通过相干腔场并通过对原子与腔场的探测作联合测量.当|α|1时,可以用探测正交态的方法探测腔场.最后接收者根据由经典通道得到的联合测量结果重构初始态.方案的特点是用一个相干态与多个原子的纠缠态作为量子通道,简单易行.该方案有望在证明量子非定域性和量子信息过程中有重要的应用价值. 相似文献
12.
In the system with two two-level ions confined in a linear trap,
this paper presents a simple scheme to realize the quantum phase
gate (QPG) and the swap gate beyond the Lamb--Dicke (LD) limit.
These two-qubit quantum logic gates only involve the internal states
of two trapped ions. The scheme does not use the vibrational mode as
the data bus and only requires a single resonant interaction of the
ions with the lasers. Neither the LD approximation nor the auxiliary
atomic level is needed in the proposed scheme. Thus the scheme is
simple and the interaction time is very short, which is important in
view of decoherence. The experimental feasibility for achieving this
scheme is also discussed. 相似文献
13.
Distributed quantum computation with superconducting qubit via LC circuit using dressed states 下载免费PDF全文
A scheme is proposed where two superconducting qubits driven by a classical field interacting separately with two distant LC circuits connected by another LC circuit through mutual inductance,are used for implementing quantum gates.By using dressed states,quantum state transfer and quantum entangling gate can be implemented.With the help of the time-dependent electromagnetic field,any two dressed qubits can be selectively coupled to the data bus (the last LC circuit),then quantum state can be transferred from one dressed qubit to another and multi-mode entangled state can also be formed.As a result,the promising perspectives for quantum information processing of mesoscopic superconducting qubits are obtained and the distributed and scalable quantum computation can be implemented in this scheme. 相似文献
14.
提出了一个实现两离子量子逻辑门的简单方案。本方案使用了两个囚禁于线性阱的三能级离子。本方案不使用振动模作为数据总线,仅需要激光与离子的单个相互作用,因而相互作用时间变短,这点从退相干的角度看是很重要的,而且本方案对振动模的加热不敏感。 相似文献
15.
Zhi-Bo Feng Zi-Liang Cai Chunli Zhang Libo Fan Tuanhui Feng 《Optics Communications》2010,283(9):1975-1978
We propose a feasible scheme to transfer quantum information with Cooper-pair box qubits arrayed in a circuit QED. Qubits interact with a quantum data bus generated by a one-dimensional transmission line resonator. Based on the Raman adiabatic passage, the cavity bus-assisted quantum population transfer between any selected pair of qubits can be controlled by addressing the applied gate pulses. Therefore, the scheme provides the possibility for effectively implementing scalable quantum information transfer with Josephson devices. 相似文献
16.
Simple operations and robust results are always of interest for any quantum tasks. Herein, a novel scheme is proposed for implementing a Fredkin gate via the virtual excitation of an atom-cavity-fiber system. The scheme is to control the nonlocal state-swap of two spatially separated target atoms according to the state of the control atom at hand. In the scheme, only the control atom at hand needs the laser to drive and the virtual excitation of the atom-cavity-fiber system effectively suppresses the decoherence. By numerical simulations, appreciated parameters are chosen and it is shown that the Fredkin gate can be implemented with high fidelity. Although the operation time error has slightly stronger influence on the fidelity than atom-cavity coupling strength error, the robustness of the scheme can be effectively improved against the operation time error by adopting Gaussian pulse to replace the constant pulse. In addition, the scheme can be generalized to implement alternative Fredkin gates by controlling the non-local state-swap of two remote atoms or of two remote and spatially separated atoms, which will be undoubtedly of benefit to the distributed quantum computation and remote quantum information processing. 相似文献
17.
YE Liu XIONG Wei LI AiXia & GUO GuangCan Anhui Key Laboratory of Information Material & Devices School of Physics & Material Science Anhui University Hefei China Laboratory of Quantum Information University of Science Technology of China Hefei 《中国科学:物理学 力学 天文学(英文版)》2011,(2)
We propose a scheme to implement ancilla-free 1 to 2 optimal phase covariant quantum cloning with atoms trapped in cavities.In the scheme the W-class state of three atoms,which are individually trapped in three spatially separated cavities,is deterministically generated.Then by the use of this W-class state and detection of the atomic state,an optimal ancilla-free 1 to 2 phase-covariant quantum cloning between two spatially separated trapped atoms can be realized.The scheme is robust for atomic spontaneous ... 相似文献
18.
我们提出一个利用腔QED技术控制传输任意两原子态的方案.在此方案中,我们选择一个GHZ态和一个EPR对作为量子通道.在控制者的帮助下,发送者可以把量子信息传送给接收者.在传输过程中,两对原子分别与两个全同单模场相互作用,同时两对原子分别由两个全同经典场驱动.该方案对腔衰变和热场不敏感,并且传输成功的几率为1. 相似文献
19.
Shuai Liu Jun-Hui Shen Ri-Hua Zheng Yi-Hao Kang Zhi-Cheng Shi Jie Song Yan Xia 《Frontiers of Physics》2022,17(2):21502
In this paper, we propose a scheme for implementing the nonadiabatic holonomic quantum computation (NHQC+) of two Rydberg atoms by using invariant-based reverse engineering (IBRE). The scheme is based on Förster resonance induced by strong dipole–dipole interaction between two Rydberg atoms, which provides a selective coupling mechanism to simply the dynamics of system. Moreover, for improving the fidelity of the scheme, the optimal control method is introduced to enhance the gate robustness against systematic errors. Numerical simulations show the scheme is robust against the random noise in control fields, the deviation of dipole–dipole interaction, the Förster defect, and the spontaneous emission of atoms. Therefore, the scheme may provide some useful perspectives for the realization of quantum computation with Rydberg atoms. 相似文献
20.
We introduce a tight-binding chain with a single impurity to act as a quantum data bus for perfect quantum state transfer. Our proposal is based on the weak coupling limit of the two outermost quantum dots to the data bus, which is a gapped system induced by the impurity. By connecting two quantum dots to two sites of the data bus, the system can accomplish a high-fidelity and long-distance quantum state transfer. Numerical simulations for finite system show that the numerical and analytical results of the effective coupling strength agree well with each other. Moreover, we study the robustness of this quantum communication protocol in the presence of disorder in the couplings between the nearest-neighbor quantum dots. We find that the gap of the system plays an important role in robust quantum state transfer. 相似文献