共查询到20条相似文献,搜索用时 31 毫秒
1.
N. Sangouard X. Lacour S. Guérin H. R. Jauslin 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,37(3):451-456
We propose a scheme for the construction of a CNOT gate by
adiabatic passage in an optical cavity. In opposition to a previously proposed method, the technique is not based on fractional
adiabatic passage, which requires the control of the ratio of two pulse amplitudes. Moreover, the technique constitutes a
decoherence-free method in the sense that spontaneous emission and cavity damping are avoided since the dynamics follows dark
states. 相似文献
2.
Yang Fan 《中国光学快报(英文版)》2005,3(3)
We propose a scheme to implement a quantum controlled-NOT (CNOT) gate between two four-level atoms inside the detuned optical cavity. The system state is evolved inside the decoherence-free (DF) subspace through stimulated Raman processes, which yields the desired unitary evolution operation for the CNOT.Our scheme is immune to decoherence due to dissipation of cavity excitation and spontaneous emission from the excited atomic level. 相似文献
3.
4.
We propose two schemes for implementing a two-atom quantum iswap gate via cavity QED. In the first scheme, only one cavity
and two classical fields are used to realizing iswap gate and thus reducing the operating time. The second scheme needs three
cavities for atom-cavity interaction and single-qubit rotations without the assistant of the auxiliary level. Our schemes
can effectively reduce the cavity decay owing to the reason that the cavity is only virtually excited during the interaction
process between atoms and the cavity. Operator fidelity is applied to analyzing the influence when two atoms enter a cavity
without accurate simultaneity. 相似文献
5.
Chui-Ping Yang 《Physics letters. A》2008,372(18):3168-3175
We propose a new scheme for realizing a distant two-qubit controlled-U gate with nearest qubit-qubit interaction. The present scheme does not need measurement. Furthermore, it is noted that the two-qubit CNOT gates required by the scheme are greatly reduced when compared with the conventional method based on SWAP operations. The scheme is useful in quantum computing with solid-state systems where only interaction between nearest systems is available. 相似文献
6.
Remote interactions between two d-dimensional distributed quantum systems: nonlocal generalized quantum control-NOT gate and entanglement swapping 下载免费PDF全文
We present a systematic simple method to implement a generalized quantum control-NOT (CNOT) gate on two d-dimensional distributed systems. First, we show how the nonlocal generalized quantum CNOT gate can be implemented with unity fidelity and unity probability by using a maximally entangled pair of qudits as a quantum channel. We also put forward a scheme for probabilistically implementing the nonlocal operation with unity fidelity by employing a partially entangled qudit pair as a quantum channel. Analysis of the scheme indicates that the use of partially entangled quantum channel for implementing the nonlocal generalized quantum CNOT gate leads to the problem of 'the general optimal information extraction'. We also point out that the nonlocal generalized quantum CNOT gate can be used in the entanglement swapping between particles belonging to distant users in a communication network and distributed quantum computer.[第一段] 相似文献
7.
Generation of four-atom cluster states in thermal cavity and implementing remote controlled not gate 总被引:2,自引:0,他引:2 下载免费PDF全文
We propose an experimentally feasible scheme for preparing a four-atom cluster state
in a thermal cavity. In the scheme, the cavity field is only virtually excited and
the photon-number-dependent part in the effective Hamiltonian is cancelled so that
the system is insensitive to the cavity decay and the thermal field. At the same
time, the scheme can be generalized to prepare n-atom cluster states with the
success probability 100\%. In addition, using the four-atom cluster state, we also
propose a simpler scheme for implementing a remote--controlled not gate (CNOT)
without the Bell states measurement. 相似文献
8.
We present a scheme for locally concentrating a non-maximally entangled four-photon cluster state into a maximally-entangled four-photon cluster state. This scheme has a high success probability. The controlled-NOT (CNOT) gate is a crucial ingredient in this scheme, and we use a nearly deterministic CNOT gate, which is similar with that first introduced by Nemoto et al. (Phgs. Rev. Lett., 2004, 93: 250502). This CNOT gate has a simple structure and does not need the strong nonlinearity. 相似文献
9.
Teleporting a quantum controlled-Not with one target/two targets gate using two partially entangled states 下载免费PDF全文
This paper considers the teleportation of quantum controlled-Not
(CNOT) gate by using partially entangled states. Different from the
known probability schemes, it presents a method for teleporting a
CNOT gate with unit fidelity and unit probability by using two
partially entangled pairs as quantum channel. The method is
applicable to any two partially entangled pairs satisfying the
condition that their smaller Schmidt coefficients μ and ν
are (2μ + 2ν - 2μν - 1)≥0. In this scheme, the
sender's local generalized measurement described by a positive
operator valued measurement (POVM) lies at the heart. It constructs
the required POVM. It also puts forward a scheme for teleporting a
CNOT with two targets gate with unit fidelity by using same quantum
channel. With assistance of local operations and classical
communications, three spatially separated users are able to complete
the teleportation of a CNOT with two targets gate with probability
of (2μ + 2ν- 1). With a proper value of μ and ν,
the probability could reach nearly 1. 相似文献
10.
We present a quantum CNOT logic gate based on interaction of a three-level cesium atom with a two-mode electromagnetic field
in a high-Q superconducting cavity. The three-level atom acts as a control qubit and the two-mode electromagnetic field serves as a target
qubit. Presently available QED experiments make it feasible to realize the theoretical suggestion in the laboratory. We determine
the feasibility of our proposal by calculating the fidelity. 相似文献
11.
提出利用二粒子部分纠缠态概率性地实现开靶目标的非局域量子可控非(CNOT)门的操控方案.首先考虑利用3个二粒子部分纠缠态实现3个靶目标共享的非局域量子CNOT门的受控操作,然后将该方案推广到N个靶目标共享的情形. 在该方案中,控制端Alice的局域正定算符值测量(POVM)起着关键作用,给出了该测量算符的数学表式.值得注意的是, 用二粒子部分纠缠态可确定性地实现非局域CNOT门.
关键词:
二粒子部分纠缠态
非局域可控非门
开靶目标
正定算符值测量 相似文献
12.
CHEN Chang-Yong 《理论物理通讯》2008,49(4):871-876
We propose a potentially practical scheme to implement an approximate three-qubit Toffoli gate by a single resonant interaction in dissipative cavity QED in which the cavity mode decay and atomic spontaneous emission are considered. The scheme does not require two-qubit controlled-NOT gates but uses a three-qubit phase gate and two Hadamard gates, where the approximate phase gate can be implemented by only a single dissipative resonant interaction of atoms with the cavity mode. Discussions are made for the advantages and the experimental feasibility of our scheme. 相似文献
13.
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
14.
Chui-Ping Yang 《Physics letters. A》2008,372(16):2782-2786
We present a new scheme for realizing a n-qubit controlled-phase gate with atoms in cavity QED. The present scheme operates essentially by exchanging a single photon between the control atoms and the cavity mode before and after a phase shift performed on the target atom. It is interesting to note that the gate can be implemented in a very simple way and by employing resonant interaction with one cavity only. 相似文献
15.
Abstract We propose a deterministic and scalable scheme to construct a two-qubit controlled-NOT (CNOT) gate and realize entanglement swapping between photonic qubits using a quantum-dot (QD) spin in a double-sided optical microcavity. The scheme is based on spin selective photon reflection from the cavity and can be achieved in a nondestructive and heralded way. We assess the feasibility of the scheme and show that the scheme can work in both the weak coupling and the strong coupling regimes. The scheme opens promising perspectives for long-distance photonic quantum communication and distributed quantum information processing. 相似文献
16.
Yong He Yun Deng Hui-Ran Li Ming-Xing Luo 《International Journal of Theoretical Physics》2016,55(3):1526-1535
There are many important works about the construction of universal quantum logic gates which are key elements in quantum computation. However, most of them focus on quantum transformations on the same degree of freedom (DOF) of quantum systems. We propose a CNOT gate performed on the polarization DOF and spatial mode DOF of one photon system assisted by a quantum dot in double-side optical microcavities. This hyper CNOT gate is implemented by using spin selective photon reflection from the cavity, without auxiliary spatial modes or polarization modes. This interface can also be used to construct a hyper photonic Bell-state analyzer. The high fidelities of the hyper CNOT gates may be achieved with low side leakage and cavity loss. 相似文献
17.
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
18.
Anyons can be used to realize quantum computation, because they are two-level systems in two dimensions. In this paper, we propose a scheme to simulate single-qubit gates and CNOT gate using Abelian anyons in the Kitaev model. Two pairs of anyons (six spins) are used to realize single-qubit gates, while ten spins are needed for the CNOT gate. Based on these quantum gates, we show how to realize the Grover algorithm in a two-qubit system. 相似文献
19.
Based on superconducting quantum interference devices (SQUIDs) coupled to a cavity, we propose a scheme for implementing n SWAP gates simultaneously. In our scheme, the SQUID works in the charge regime, the quantum logic gate operations are performed in the subspace spanned by two charge states |0〉 and |1〉. The interaction between the qubits and the cavity field can be achieved by turning the gate voltage and the external flux. Especially, the gate operation time is independent of the number of the qubits, and the gate operation is insensitive to the initial state of the cavity mode. We also analyze the experimental feasibility that the conditions of the large detuning can be achieved by adjusting the frequency of the cavity mode, and the operation time satisfies the requirement for the designed experiment by choosing suitable detuning and the quality factor of the cavity. Based on the simple operation, our scheme may be realized in this solid-state system, and our idea may be realized in other systems. 相似文献
20.
We propose a scheme for controllably implementing an N-qubit phase gate by one step within a ground-state subspace of N three-state atoms trapped in a cavity through a double Raman passage.We can extend our scheme to the realisation of an arbitrary N-qubit phase gate by appropriately adjusting coupling strengths and detunings between atoms and external driving fields.The advantage of this one-step scheme is its robustness against decoherence. 相似文献