A SCHEME FOR REALIZATION OF TWO-QUBIT LOGIC GATES IN CAVITY QED

2010 ◽  
Vol 24 (01) ◽  
pp. 59-64
Author(s):  
BAO-LONG FANG ◽  
HONG-BO WAN ◽  
LIU YE
Keyword(s):  
Cavity Qed ◽  
Thermal Field ◽  
Cavity Mode ◽  
Logic Gate ◽  
Logic Gates ◽  
Classical Field ◽  
Simple Scheme ◽  
Cavity Decay ◽  
Swap Gate ◽  
Phase Gate

We propose a simple scheme for realizing two-qubit logic gate in cavity QED. In our scheme, the quantum controlled-not gate, phase gate and swap gate can be implemented without the ancillary level. The quantum controlled-not gate and phase gate can be realized easily by only one interaction between atoms and a highly detuned cavity mode with the assistance of a strong classical field. Thus, the scheme is insensitive to both the cavity decay and the thermal field.

SCHEME FOR IMPLEMENTING QUANTUM DENSE CODING USING MULTI-ATOM IN CAVITY QED

2008 ◽  
Vol 06 (03) ◽  
pp. 517-523 ◽  
Author(s):  
LIU YE ◽  
BAO-LONG FANG
Keyword(s):  
Cavity Qed ◽  
Thermal Field ◽  
Cavity Mode ◽  
Classical Field ◽  
Atomic State ◽  
Dense Coding ◽  
Quantum Dense Coding ◽  
Ghz States ◽  
Cavity Decay

We propose an experimentally feasible scheme for implementing quantum dense coding in cavity QED. In this scheme, the multi-atoms interact simultaneously with a highly detuned cavity mode, and are driven by a strong classical field. The scheme is insensitive to the cavity decay and the thermal field. Only one interaction between atoms and cavity is required. Multi-atom's GHZ-states can be exactly distinguished via detecting the atomic state, and the quantum dense coding can be realized in a simple way.

Realizing an N-two-qubit quantum logic gate in a cavity QED with nearest qubit--qubit interaction

2016 ◽  
Vol 16 (5&6) ◽  
pp. 465-482
Author(s):  
Taoufik Said ◽  
Abdelhaq Chouikh ◽  
Karima Essammouni ◽  
Mohamed Bennai
Keyword(s):  
Quantum Logic ◽  
Cavity Qed ◽  
Logic Gate ◽  
Operation Time ◽  
Logic Gates ◽  
Initial State ◽  
Gate Operation ◽  
Quantum Logic Gates ◽  
Current State ◽  
Phase Gate

We propose an effective way for realizing a three quantum logic gates (NTCP gate, NTCP-NOT gate and NTQ-NOT gate) of one qubit simultaneously controlling N target qubits based on the qubit-qubit interaction. We use the superconducting qubits in a cavity QED driven by a strong microwave field. In our scheme, the operation time of these gates is independent of the number N of qubits involved in the gate operation. These gates are insensitive to the initial state of the cavity QED and can be used to produce an analogous CNOT gate simultaneously acting on N qubits. The quantum phase gate can be realized in a time (nanosecond-scale) much smaller than decoherence time and dephasing time (microsecond-scale) in cavity QED. Numerical simulation under the influence of the gate operations shows that the scheme could be achieved efficiently within current state-of-the-art technology.

PROBABILISTIC TELEPORTATION OF A TWO-ATOM ENTANGLED STATE IN CAVITY QED

2008 ◽  
Vol 22 (13) ◽  
pp. 2129-2137
Author(s):  
JIN-MING LIU ◽  
YI-CAI WANG ◽  
XIAO-QI XIAO
Keyword(s):  
Quantum Channel ◽  
Cavity Qed ◽  
Thermal Field ◽  
Cavity Mode ◽  
Resonant Cavity ◽  
Success Probability ◽  
Entangled State ◽  
Probabilistic Teleportation ◽  
Cavity Decay ◽  
Partially Entangled State

We present two schemes for probabilistically teleporting a two-atom entangled state using a three-atom partially entangled state as the quantum channel in cavity QED with the help of separate atomic measurements. The first scheme is only based on the interaction between two driven atoms and a quantized cavity mode in the large detuning limit, so the effects of both cavity decay and the thermal field are eliminated. In the second scheme, it is necessary to introduce an additional resonant cavity besides the thermal cavity to realize the teleportation, and the corresponding success probability is improved.

EFFICIENT TELEPORTATION OF UNKNOWN ATOMIC ENTANGLED STATES

2006 ◽  
Vol 04 (04) ◽  
pp. 627-631 ◽  
Author(s):  
YAN ZHAO ◽  
MING YANG ◽  
ZHUO-LIANG CAO
Keyword(s):  
Cavity Qed ◽  
Thermal Field ◽  
Photon Number ◽  
Success Probability ◽  
Bell State ◽  
Classical Field ◽  
Entangled States ◽  
Effective Hamiltonian ◽  
State Measurement ◽  
Cavity Decay

We propose a scheme for teleporting unknown atomic entangled states in cavity QED. With the assistance of a strong classical field, the photon number dependent parts in the effective Hamiltonian are canceled. Thus, the scheme is insensitive to both the cavity decay and the thermal field. In addition, our scheme does not require the Bell-state measurement directly and the success probability can reach 1.0 in our scheme.

DYNAMIC PROPERTIES OF THE LARGE-DETUNING CAVITY QED SYSTEM IN THE PRESENCE OF CAVITY DECAY

2008 ◽  
Vol 22 (26) ◽  
pp. 2561-2570
Author(s):  
CHENG-YUAN GAO ◽  
LEI MA ◽  
JIN-MING LIU
Keyword(s):  
Cavity Qed ◽  
Dynamic Properties ◽  
Photon Number ◽  
Quantum Phase Gate ◽  
Cavity Decay ◽  
Phase Gate ◽  
Physical Quantities ◽  
Population Probability ◽  
Average Photon Number ◽  
Epr State

We consider a physical process of two Λ-type three-level atoms interacting with a bimodal cavity including the influence of the cavity decay. We analyze the influence of cavity decay on several physical quantities of the process, such as atomic population probability, residual entanglement, concurrence of two atoms, average population inversion, average photon number, the fidelity for quantum phase gate, and the fidelity of generating atomic EPR state. It is found that all of these physical quantities decrease with the increase of cavity decay when the other relevant parameters are fixed.

BIDIRECTIONAL QUANTUM SECURE DIRECT COMMUNICATION IN DRIVEN CAVITY QED

2009 ◽  
Vol 23 (27) ◽  
pp. 3225-3234 ◽  
Author(s):  
CHUAN-JIA SHAN ◽  
JI-BING LIU ◽  
WEI-WEN CHENG ◽  
TANG-KUN LIU ◽  
YAN-XIA HUANG ◽  
...  
Keyword(s):  
Cavity Qed ◽  
Thermal Field ◽  
Success Probability ◽  
Bell State ◽  
Quantum Secure Direct Communication ◽  
Entanglement Swapping ◽  
Direct Communication ◽  
Driven Cavity ◽  
Cavity Decay ◽  
Probability Of Success

A theoretical scheme of bidirectional quantum secure direct communication is proposed in the context of driven cavity QED. We first present an entanglement swapping scheme in cavities where two atoms without previous interaction can be entangled with a success probability of unity. Then, based on a novel property of entanglement swapping, we propose a bidirectional quantum secure direct communication protocol, in which two legitimate users can exchange their different secret messages simultaneously in a direct way. The probability of success in our scheme is 1.0. This scheme does not involve apparent (or direct) Bell-state measurements and is insensitive to the cavity decay and the thermal field.

SECRET SHARING OF N-ATOM ENTANGLED STATE IN CAVITY QED

2007 ◽  
Vol 18 (03) ◽  
pp. 343-349 ◽  
Author(s):  
ZHONG-XIAO MAN ◽  
YUN-JIE XIA ◽  
ZHAN-JUN ZHANG
Keyword(s):  
Secret Sharing ◽  
Cavity Qed ◽  
Thermal Field ◽  
Bell State ◽  
Entangled State ◽  
Quantum Channels ◽  
Driven Cavity ◽  
Bell State Measurement ◽  
State Measurement ◽  
Cavity Decay

We propose a scheme to secret sharing of an unknown N-atom entangled state in driven cavity QED. The scheme needs only atomic Bell states as the quantum channels and joint Bell-state measurement is unnecessary. In addition, the scheme is insensitive to the cavity decay and the thermal field.

DISCRIMINATING 16 MUTUALLY ORTHOGONAL 4-ATOM CLUSTER STATES VIA CAVITY QED IN TELEPORTING ARBITRARY UNKNOWN TWO-ATOM STATE WITH A 4-ATOM CLUSTER STATE AS QUANTUM CHANNEL

2008 ◽  
Vol 19 (05) ◽  
pp. 741-747 ◽  
Author(s):  
WEN ZHANG ◽  
YI-MIN LIU ◽  
ZHANG-YIN WANG ◽  
ZHAN-JUN ZHANG
Keyword(s):  
Quantum Channel ◽  
Cavity Qed ◽  
Thermal Field ◽  
Cluster State ◽  
Photon Number ◽  
Effective Hamiltonian ◽  
Cluster States ◽  
Present Scheme ◽  
Atom Cluster ◽  
Cavity Decay

We propose a scheme for discriminating 16 mutually orthogonal 4-atom cluster entangled states (CES) via cavity QED in teleporting an arbitrary unknown two-atom state with a 4-atom CES as quantum channel. Utilizing the interaction of atoms with cavity and classical field, the complicated 4-atom CESs are transformed into the simple 4-atom product states. Hence the difficulty of measurement during the teleportation process is degraded. In the present scheme, we allow for the case of a strong classical driving field and the detuning between the atoms and the cavity is assumed large enough. Thereby the photon-number-dependent parts in the effective Hamiltonian can be neglected, and the scheme is insensitive to both the cavity decay and the thermal field.

THE TELEPORTATION OF AN ARBITRARY TWO-ATOM ENTANGLED STATE IN DRIVEN CAVITY QED

2007 ◽  
Vol 05 (03) ◽  
pp. 359-366 ◽  
Author(s):  
CHUAN-JIA SHAN ◽  
ZHONG-XIAO MAN ◽  
YUN-JIE XIA ◽  
TANG-KUN LIU
Keyword(s):  
Cavity Qed ◽  
Thermal Field ◽  
Bell State ◽  
Ghz State ◽  
Entangled State ◽  
Driven Cavity ◽  
Bell State Measurement ◽  
State Measurement ◽  
Cavity Decay ◽  
Probability Of Success

We propose a scheme for the teleportation of an arbitrary two-atom entangled state |ϕ〉12 = a|gg〉12 + b|ge〉12 + c|eg〉12 + d|ee〉12 in driven QED. Two pairs of maximally two-atom entangled state are required as the quantum channel. This scheme does not involve apparent (or direct) Bell-state measurement and is insensitive to the cavity decay and the thermal field. Meanwhile this approach can be used to teleport the unknown multipartite GHZ state. The probability of success in our scheme can reach 1.0.

IMPLEMENTING ENTANGLEMENT SWAPPING WITH A THERMAL CAVITY

2007 ◽  
Vol 05 (06) ◽  
pp. 837-843 ◽  
Author(s):  
ZHI HE ◽  
CHAO-YUN LONG ◽  
SHUI-JIE QIN ◽  
GAO-FENG WEI
Keyword(s):  
Cavity Qed ◽  
Thermal Field ◽  
Success Probability ◽  
Entanglement Swapping ◽  
Cavity Decay

We proposed a scheme to implement the entanglement swapping based on cavity QED. Using this scheme, we can obtain the entanglement swapping with the success probability of 100% for a two atoms system and a three atoms system respectively, and the entanglement swapping is insensitive to both the cavity decay and thermal field.

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