共查询到20条相似文献,搜索用时 15 毫秒
1.
We suggest a simple method to teleport an unknown superposition of the atomic internal state of a two-level atom onto transverse atomic momenta of another atom during its flight. The scheme relies on the standard cavity QED techniques and is inherently deterministic with sufficiently high fidelity for the teleported state. It is further shown that the procedure can be straightforwardly extended to remotely tune in the probability amplitudes of any atomic momenta multipartite entangled state. 相似文献
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P. Silvestrini B. Ruggiero V. G. Palmieri C. Granata E. Esposito M. Russo 《Journal of Superconductivity》1999,12(6):727-733
We present experiments on macroscopic quantum effects in Josephson junctions with different relevant junction parameters at a temperature well above the classical-quantum crossover temperature. This has been possible by extending the measurements on the escape rate out of the metastable state at higher sweeping frequency (dI/dt up to 100 A/sec.) in order to induce non-stationary conditions in the energy potential describing the junction dynamics. The non-stationary regime for the system allows a direct observation of energy level quantitation when the rate of change of the external energy, measured in terms of the level spacing, is fast with respect to the thermal transitions between levels. 相似文献
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Yan-Qiang Ji Tao Yu Hong-Fu Wang Shou Zhang Kyu-Hwang Yeon 《Journal of Modern Optics》2013,60(14):1272-1277
We present a scheme to implement a special quantum cloning machine with quantum dot spins in cavity QED. The quantum cloning machine copies the information from a photon to other two distant quantum dots trapped in cavities with the help of a single-photon pulse. Choosing the different parameters, the scheme can implement optimal symmetric 1?→?2 universal, optimal symmetric 1?→?2 phase-covariant and optimal symmetric economical 1?→?3 phase-covariant quantum cloning machines. The present scheme is more economical in saving resource compared with previous schemes. 相似文献
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Giordano Diambrini Palazzi 《Journal of Superconductivity》1999,12(6):767-772
In the second half of 1993 we presented to INFN a proposal of an experiment for detecting macroscopic quantum coherence with a system of SQUIDs. It was based essentially on ideas presented first by Leggett and collaborators and developed in many articles in the 1980s. The experimental work started in the 1994 just after the approval of the INFN. As an introduction, the experimental method and the setup we choose in order to perform a set of measurements on a system of SQUIDs is described. Then the measuring procedures and their purposes are explained and discussed.As a future perspective, a possible test on the existence of the quantum gravity is discussed. According to a theoretical proposal by John Ellis and collaborators, the quantum gravitational friction could induce the transition from QM behavior of microscopic states to the classical behavior of macroscopic states, i.e., states containing an Avogadro number (M
pl/M
e
) of elementary particles, as may be obtained in a SQUID. 相似文献
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A new trapping effect of a three-level atom in interaction with a bimodal cavity field is proposed. This problem consists of the possibility for realization of initially separated states of an atom and an electromagnetic field after interaction. The quantum properties of a bimodal field, which satisfy the reversible conditions for the atom flying through the cavity, were studied. 相似文献
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Wei Wu 《Journal of Modern Optics》2017,64(12):1175-1183
We investigate the dynamics of geometric quantum correlations for certain decoherence channels and discuss the necessary conditions for the existence of frozen geometric discord. As illustrative examples, we study the phenomenon of double sudden transitions in geometric discord for a system consisting of two noninteracting atoms inserted in two independent dissipative cavities and how the initial state parameters and decay rate of dissipative cavities affect the frozen time during which the geometric discord remains constant. We also explore the dynamics of geometric discord between two noninteracting atoms trapped in a common dissipative cavity and find that the geometric discord exhibits sudden transition between classical and quantum decoherence. Moreover, a nonzero stationary geometric discord can arise in both the independent cavity case and common cavity case. 相似文献
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Willa Rawlinson 《Journal of Modern Optics》2013,60(13):1061-1067
We study the quantum discord for a system of two identical coupled quantum dots interacting with quantized cavity field in the presence of cavity as well as dot decay and detuning. The cavity is externally driven by a coherent light. These results are compared with the entanglement of the quantum dots in various parameter regimes in which system may or may not show bistability. We show that the discord in the steady state is nonzero for any nonzero cavity field amplitude. The system has higher discord in the upper branch of the bistability curve where the entanglement is zero. We also find many other interesting results including high discord and entanglement in the presence of detuning, a phenomenon which we further examine by approximating the density matrix in the appropriate limit. 相似文献
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The geometric phase (GP) in cavity QED filled with a nonlinear medium and containing a quantum well is analyzed. We observe collapses and revivals. The optical nonlinearity leads to high frequency oscillations of the GP. The GP is very sensitive not only to the dissipation rates but also to the amplitude of the laser pump. 相似文献
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A model is presented to calculate the optical force and friction for a three-level atom in a V-type configuration in a weakly driven high-finesse cavity. Analytical expressions for the force and friction are derived using Heisenberg equations. It is demonstrated that the cooling rate can be increased by one order of magnitude over that of a two-level atomic system, which would stimulate further experimental investigations. 相似文献
11.
We have studied optical pulse propagation in a Raman fiber amplifier doped with a three-level medium and driven by a control laser pulse. We analyze the spatial-temporal dynamics of pulse propagation for different atomic initial conditions. The propagation of an optical pulse through the amplifier can be sustained by a control laser that induces transparency via quantum coherence, which is useful for extending the distance between optical repeaters. Under certain conditions, amplification is achieved without population inversion. The results could be useful for laser control of optical pulses in amplifiers and waveguides. 相似文献
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L. S. Schulman 《Journal of Superconductivity》1999,12(6):703-706
Experimental observations of quantum jumps suggest that one can associate a time scale shorter than the usual lifetime with quantum transitions. Two such scales are discussed here, and their relation to experiments and to other theoretical ideas is explored. 相似文献
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E. Pazy T. Calarco I. D''Amico P. Zanardi F. Rossi P. Zoller 《Journal of Superconductivity》2003,16(2):383-385
We propose a spin-based ultra-fast laser driven implementation of quantum information processing based on the Pauli blocking effect in semiconductors, which acts as a spin dependent switching mechanism for auxiliary exciton states. 相似文献
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根据么正变换理论,并结合SU(1 ,1)Lie 代数,对超细颗粒的量子尺寸效应进行详细研讨。结果表明,超细颗粒的能级随时间变化,并且是精确的。 相似文献
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介绍了半导体量子点材料禁阻类型,详细阐述了共熔法、溶胶-凝胶法、离子注入法等半导体量子点玻璃材料的制备方法,探讨了半导体量子点玻璃的尺寸效应、禁阻效应、库仑阻塞效应和非线性光学效应等特性及其未来应用前景. 相似文献