scholarly journals One-step implementation of the Fredkin gate via quantum Zeno dynamics

2012 ◽  
Vol 12 (3&4) ◽  
pp. 215-230
Author(s):  
Zhi-Cheng Shi ◽  
Yan Xia ◽  
Jie Song ◽  
He-Shan Song
Keyword(s):  
Numerical Calculation ◽  
Spontaneous Emission ◽  
Success Probability ◽  
Interaction Time ◽  
Quantum Zeno Dynamics ◽  
Cavity Decay ◽  
Fredkin Gate ◽  
One Step

We study one-step implementation of the Fredkin gate in a bi-modal cavity under both resonant and large detuning conditions based on quantum Zeno dynamics, which reduces the complexity of experiment operations. The influence of cavity decay and atomic spontaneous emission is discussed by numerical calculation. The results demonstrate that the fidelity and the success probability are robust against cavity decay in both models and they are also insensitive to atomic spontaneous emission in the large detuning model. In addition, the interaction time is rather short in the resonant model compared to the large detuning model.

IMPLEMENTING THE ECONOMICAL 1 → M PHASE-COVARIANT QUANTUM CLONING VIA THE DETECTION OF CAVITY DECAY

2010 ◽  
Vol 24 (04n05) ◽  
pp. 411-417
Author(s):  
ZHEN YANG ◽  
BAO-LONG FANG ◽  
HONG-BO WAN ◽  
LIU YE
Keyword(s):  
Spontaneous Emission ◽  
Optical Cavity ◽  
Success Probability ◽  
Quantum Cloning ◽  
Covariant Quantum ◽  
Output State ◽  
Cavity Decay ◽  
Automatic Feedback ◽  
M Phase ◽  
Approach Unity

We propose a scheme to realize the economical 1 → M phase-covariant quantum cloning in 2-dimension with M Λ-type three-level atoms in an optical cavity. In our scheme, we do not require addressing and exactly manipulating on every atoms, never so much as controlling the time of interaction between atoms and photon. The success or failure of cloning can be determined simply by detecting the polarization of the photon leaking out of the cavity. With the use of an automatic feedback, the success probability of the scheme can be made to approach unity. And the desired output state is a superposition of different combination of two grounds states and thus is free from decoherence caused by spontaneous emission.

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.

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.

One-step implementation of the Toffoli gate via quantum Zeno dynamics

2009 ◽  
Vol 374 (1) ◽  
pp. 28-33 ◽  
Author(s):  
Xiao-Qiang Shao ◽  
Hong-Fu Wang ◽  
Li Chen ◽  
Shou Zhang ◽  
Kyu-Hwang Yeon
Keyword(s):  
Toffoli Gate ◽  
Quantum Zeno Dynamics ◽  
One Step

Implementation of a quantum $\sqrt{\rm_{swap}}$ gate for two distant atoms trapped in separate cavities

2015 ◽  
Vol 13 (01) ◽  
pp. 1550003 ◽  
Author(s):  
Xiu Lin ◽  
Rong-Can Yang ◽  
Xiang Chen
Keyword(s):  
Optical Fiber ◽  
Quantum Computation ◽  
Spontaneous Emission ◽  
Atomic System ◽  
Whole Process ◽  
Cavity Modes ◽  
Cavity Decay ◽  
Swap Gate ◽  
Separate Cavities

We present a scheme to implement a quantum [Formula: see text] gate for two-atom trapped in distant cavities connected via an optical fiber. In the whole process, the atomic system, the cavity modes and the fiber are not excited ensuring that the operation is insensitive to atomic spontaneous emission, cavity decay and the fiber loss. This scheme is significant for distributed and scalable quantum computation.

ENTANGLEMENT GENERATION WITH GEOMETRIC OPERATIONS IN CAVITY QED

2009 ◽  
Vol 23 (13) ◽  
pp. 1619-1624
Author(s):  
GANG ZHANG ◽  
PING DONG ◽  
ZHUO-LIANG CAO
Keyword(s):  
Spontaneous Emission ◽  
Cavity Qed ◽  
Laser Power ◽  
Cavity Mode ◽  
Thermal State ◽  
Cluster State ◽  
Entanglement Generation ◽  
State Generation ◽  
One Step ◽  
Geometric Nature

We propose a one-step cluster state generation scheme via atomic cavity QED. The current scheme is insensitive to the cavity mode thermal state as well as the atomic spontaneous emission since the gate operations are independent of the cavity mode states and laser power is sufficiently weak. In addition, the needed operation is of geometric nature, so it is robust against random operation errors.

Sign in / Sign up

Export Citation Format

Share Document