共查询到10条相似文献,搜索用时 78 毫秒
1.
In this paper, we study the control problem of adiabatic decoherence in a three-level atom. We will find the decoupling bang-bang group for various configurations, including the V configuration and the cascade type of three-levelatom subjected to adiabatic decoherence. We also give the programs to design a sequence of periodic twinborn pulses to suppress the decoherence. 相似文献
2.
我们利用腔场和激光相互作用,提出一个冗余的、对消相干不敏感的方案,来传输任意一个三能级原子的态.由于原子自发跃迁和腔延迟作用会造成信息丢失,通过用部分绝热过程和适当的原子场耦合的设计,信息丢失能够被有效的抑制,此方案传送成功的几率是0.5,保真度是1. 相似文献
3.
We study the phase probability distribution of a three-level atom interacting with a cavity field in the presence of two-photon detuning and decoherence. Anabiosis of the phase probability distribution is observed due to the presence of the Stark shift. The simulation demonstrates that there is an enhancement of the phase sensitivity as soon as the two-photon detuning is considered. The W-Wigner function is also examined and it is shown that the nonclassical effect is apparent, however, for a small value of the decoherence factor. 相似文献
4.
We present a scheme to realize the basic two-qubit logic gates such as the quantum phase gate and SWAP gate using a detuned microwave cavity interacting with three-level superconducting-quantum-interference-device (SQUID) qubit(s), by placing SQUID(s) in a two-mode microwave cavity and using adiabatic passage methods. In this scheme, the two logical states of the qubit are represented by the two lowest levels of the SQUID, and the cavity fields are treated as quantized. Compared with the previous method, the complex procedures of adjusting tile level spacing of the SQUID and applying the resonant microwave pulse to the SQUID to create transformation are not required. Based on superconducting device with relatively long decoherence time and simplified operation procedure, the gates operate at a high speed, which is important in view of decoherence. 相似文献
5.
Jun He Yong-Sheng Zhang Xiang-Fa Zhou Qun-Feng Chen Guang-Can Guo 《Optics Communications》2009,282(6):1167-1170
An method for adiabatic population transfer and the preparation of an arbitrary quantum superposition state using the oscillating dark states (ODS) in atomic system is presented. Quantum state of a three-level Λ configuration atomic system finally evolves into the same time-dependent state, and oscillates periodically between two ground levels under evolving adiabatic conditions when two pairs of classical detuning laser fields drive the system into the ODS forcedly, whatever the initial states of the system are. The decoherence of the ODS evolution is greatly suppressed and the oscillation is very stable, therefore adiabatic population transfer and the preparation of an arbitrary quantum superposition state of atomic system can be completed accurately and conveniently. 相似文献
6.
A three-level system based an a three-level atom interacting with a detuned cavity is considered. Because of the fact that the three-level atom defines a total normalized state composed of superposition of three different single-level states, it is assumed that such a system implements a qutrit. In order to achieve a quantum NOT gate for a single qutrit, the respective Schrödinger equation is solved numerically within a two-photon rotating wave approximation. For small values of one-photon detuning, there appear decoherence effects. Meanwhile, for large values of one-photon detuning, an ideal quantum NOT gate for a single qutrit is achieved. An expression for the execution time of the quantum NOT gate for a single qutrit as a function of the one-photon detuning is found. 相似文献
7.
Two-qutrit maximally entangled states prepared via adiabatic passage in ion-trapped system 下载免费PDF全文
This paper considers a scheme for the preparation of two-qutrit entangled states via adiabatic passage in iontrapped system.In the proposal,the two three-level V-type ions are initially cooled to the ground states and need not be separately addressed.Moreover,only the ionic states act as memory and the system evolves in the dark space during the whole procedure,which makes the system robust against the decoherence and the fluctuation of the laser pulse. 相似文献
8.
Z. J. Deng L.-M. Liang W. L. Yang 《International Journal of Theoretical Physics》2010,49(8):1904-1910
We propose a simple scheme to implement multi-qubit quantum Grover search with atomic ensembles by adiabatic passage. The
scheme is immune to the atomic spontaneous emission, cavity decay and fiber decay. Furthermore, the process can be speeded
up with atomic ensemble instead of single atom, which is important in view of decoherence. With each atomic ensemble confined
in an individual cavity, our scheme is experimentally scalable to multi-qubit cases. 相似文献
9.
REN XueZao CONG HongLu WANG XuWen & XIA JianPing School of Science Southwest University of Science Technology Mianyang China Physics Group Beijing Jiaotong University Hai Bin College Huanghua 《中国科学:物理学 力学 天文学(英文版)》2011,(9)
In this paper, the quantum entanglement between a single mode binomial field and a cascade three-level atom is calculated mechanically without the rotating wave approximation. The numerical results indicate that the quantum entanglement at the first few periods is reduced notably due to the fact that the atom is initially in the superposition state. With increasing field parameter , the period of the entanglement evolution becomes obvious and the quantum decoherence phenomenon emerges in a short time. 相似文献
10.
In this talk, the interaction of a single photon injected to a single atom is studied, for which initially the photon is uncorrelated with the atom. The spontaneous emitted photon will then evolve to be entangled with the atom on their continuous kinetic variables (momentum) in the process of resonant scattering. We find the relations between the entanglement and their physical control parameters (such as the linewidth of the injected photon wave packet, and that of the atomic wave packet, etc. ), which indicates that high entanglement can be reached by broadening the scale of the atomic wave or squeezing the linewidth of the incident single-photon pulse. 相似文献