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51.
Two simple schemes for implementing Toffoli gate via atom--cavity field interaction in cavity quantum electrodynamics 下载免费PDF全文
This paper proposes two schemes for implementing three-qubit Toffoli
gate with an atom (as target qubit) sent through a two-mode cavity
(as control qubits). The first scheme is based on the large-detuning
atom--cavity field interaction and the second scheme is based on the
resonant atom-field interaction. Both the situations with and
without cavity decay and atomic spontaneous emission are considered.
The advantages and the experimental feasibility of these two schemes
are discussed. 相似文献
52.
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
53.
Implementation of positive-operator-value measurements for single spin qubit via Heisenberg model 下载免费PDF全文
This paper shows that a proposal for implementing all possible two-operator positive-operator-value measurements of single spin qubit can be obtained via introducing another spin qubit as ancilla. The realization process is accomplished from the free evolution of the Heisenberg XX model by considering nearest-neighbour spin interaction. A controlled-NOT gate, which is a significant operator for this scheme is also constructed and the generalisation to multiple-operator is considered finally. 相似文献
54.
Schemes for two-qubit and three-qubit controlled gates based on cross-Kerr nonlinearity are proposed in this paper.The probability of the success of these gates can be increased by quantum nondemolition detectors,which are used to judge which paths the signal photons pass through.These schemes are almost deterministic and require no ancilla photon.The advantages of these gates over the existing ones include less resource consumption and a higher probability of success,which make our schemes more feasible with current technology. 相似文献
55.
与非等同双原子相互作用下光场的相干性质 总被引:1,自引:0,他引:1
研究了具有不同偶极矩的两个原子与双模压缩真空场相互作用系统中光场的相干性质.讨论了两个原子与双模压缩真空场的相对耦合常量(R=g1/g2)和光场的初始压缩因子r对二阶相干度、光场的模间相关性、Cauchy-Schwartz不等式的影响.结果表明,光场的初始压缩因子较小时,光子的聚束效应和反聚束效应交替出现,且光场的模间相关程度较强.光场的初始压缩因子较大时,光子呈现聚束效应,且模间相关程度较弱.双原子的相对耦合常量R对二阶相干度、光场的模间相关性、Cauchy-Schwartz不等式的时间演化规律有影响,但不能改变光场模间相关的非经典性质. 相似文献
56.
A three- and an (N+1)-party dense coding scheme in the case of non-symmetric
Hilbert spaces of the particles of a quantum channel are investigated by using a
multipartite entangled state. In the case of the (N+1)-party dense coding scheme,
we show that the amount of classical information transmitted from N senders to one
receiver is improved. 相似文献
57.
Based on entanglement swapping, a scheme for the secret sharing of an arbitrary
two-particle entangled state is proposed. If the controllers do not co-operate
with the eavesdropper, the eavesdropper's successful probability decreases with the
number of the controllers increasing.
In addition,
only the Bell-state measurements are
required to realize the secret sharing scheme. 相似文献
58.
Influence of atomic motion on the population and dipole squeezing of a cascade three-level atom in cavity field 总被引:2,自引:0,他引:2 下载免费PDF全文
The dynamical property of a cascade three-level atom is investigated in the condition of atomic motion. The influence of atomic motion on the population and dipole squeezing is discussed. The results show that atomic motion makes the amplitude of atomic population be steady and increasing the parameter εp which denotes the atomic motion and the structure of field mode can shorten the period of collapse-revivals. By choosing an appropriate parameter εp, we can obtain a dipole squeezed atom of long standing. 相似文献
59.
张寿传 《数学年刊A辑(中文版)》2001,(6)
本文证明了当H是有限维半单和余半单的Hopf代数时,R与交叉积R#σH的整体维数是相同的;同时,它们的弱维数也是相同的. 相似文献
60.
Zhi-Xu Zhang 《中国物理 B》2022,31(7):70301-070301
We investigate the topological phase transition and the enhanced topological effect in a cavity optomechanical system with periodical modulation. By calculating the steady-state equations of the system, the steady-state conditions of cavity fields and the restricted conditions of effective optomechanical couplings are demonstrated. It is found that the cavity optomechanical system can be modulated to different topological Su-Schrieffer-Heeger (SSH) phases via designing the optomechanical couplings legitimately. Meanwhile, combining the effective optomechanical couplings and the probability distributions of gap states, we reveal the topological phase transition between trivial SSH phase and nontrivial SSH phase via adjusting the decay rates of cavity fields. Moreover, we find that the enhanced topological effect of gap states can be achieved by enlarging the size of system and adjusting the decay rates of cavity fields. 相似文献