共查询到20条相似文献,搜索用时 31 毫秒
1.
We investigate the interaction of a single three-level trapped ion with two laser beams. By applying a unitary transformation and a small rotating transformation, an exact solution to this quantum system is obtained without performing the Lamb-Dicke approximation, and the trapping state is observed. 相似文献
2.
Shi-Biao Zheng 《Czechoslovak Journal of Physics》2002,52(5):713-718
We propose a method for the generation of motional pair coherent states for the center of mass and relative motional modes
for two trapped ions. The scheme is generalized to prepare pair cat states. The scheme does not require individual ionic laser
addressing. 相似文献
4.
F. Schmidt-Kaler J. Eschner G. Morigi C.F. Roos D. Leibfried A. Mundt R. Blatt 《Applied physics. B, Lasers and optics》2001,73(8):807-814
A novel method of ground-state laser cooling of trapped atoms utilizes the absorption profile of a three- (or multi-) level
system that is tailored by a quantum interference. With cooling rates comparable to conventional sideband cooling, lower final
temperatures may be achieved. The method was experimentally implemented to cool a single Ca+ ion to its vibrational ground state. Since a broad band of vibrational frequencies can be cooled simultaneously, the technique
will be particularly useful for the cooling of larger ion strings, thereby being of great practical importance for initializing
a quantum register based on trapped ions. We also discuss its application to different level schemes and for ground-state
cooling of neutral atoms trapped by a far-detuned standing wave laser field.
Received: 10 July 2001 / Published online: 23 November 2001 相似文献
5.
We propose a scheme for teleportation of an unknown two-qubit entangled state via trapped ions. In this scheme, we use the GHZ state as a quantum channel and the success probability can reach 1. The distinct advantage of our scheme is insensitive to the heating of the vibrational mode. In addition, Bell-state measurement is not required. 相似文献
6.
We present a proposal to measure field states for traveling modes. The scheme leads, in a simple and direct way, to the characteristic function of the state, yielding the determination of the Wigner function without a demanding data analysis. We employ a Mach-Zehnder interferometer including an auxiliary nonlinear medium in one arm. Analogies with other proposals to reconstruct states of stationary fields and trapped atoms are discussed. 相似文献
7.
Shi-Biao Zheng 《Czechoslovak Journal of Physics》2002,52(3):379-385
A scheme is proposed for generating two-mode SU(2) and SU(1,1) cat states for an ion trapped in a two-dimensional (2D) anisotropic
harmonic potential trap. In the scheme the ion is excited by two laser beams in the trap plane. After an interaction time,
a measurement on the internal state collapses the ion motion onto a superposition of two SU(2) or SU(1,1) coherent states
depending on the laser frequencies.
This work was supported by the National Natural Science Foundation of China under Grant No. 60008003, Fujian Provincial Natural
Science Foundation of China under Grant Nos. K20004 and F0110027, and Funds from Fuzhou University. 相似文献
8.
We propose a method to prepare multipartite entangled states such as cluster states and graph states based on the cavity input-output process and single photon measurement. Two quantum gates, a controlled phase gate and a fusion gate between two atoms trapped in respective cavities, are proposed to prepare atomic cluster states and graph states with one and two dimensions. We also introduce a scheme that can generate an arbitrary multipartite photon duster state which uses two coherent states as a qubit basis. 相似文献
9.
Quantum state transfer from light to molecules via coherent two-color photo-association
in an atomic Bose-Einstein condensate 总被引:1,自引:0,他引:1
H. Jing M. Zhan 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,42(1):183-187
By using a quantized input light, we theoretically revisit the
coherent two-color photo-association process in an atomic
Bose-Einstein condensate. Under the single-mode approximations, we
show two interesting regimes of the light transmission and the
molecular generation. The quantum state transfer from light
to molecules is exhibited, without or with the depletion of trapped atoms. 相似文献
10.
The entanglement between a single electron in the electronic states of a trapped three-level ion and the ionic vibrational modes of the trap is studied for an initially unentangled state of an electron level and a coherent phonon state. The effects of time-independent and time-dependent couplings are discussed. 相似文献
11.
We propose an optical scheme to generate cluster states of atomic qubits, with each trapped in separate optical cavity, via atom-cavity-laser interaction. The quantum information of each qubit is encoded on the degenerate ground states of the atom, hence the entanglement between them is relatively stable against spontaneous emission. A single-photon source and two classical fields are employed in the present scheme. By controlling the sequence and time of atom-cavity-laser interaction, we show that the atomic cluster states can be produced deterministically. 相似文献
12.
A. Lambrecht J. M. Courty S. Reynaud E. Giacobino 《Applied physics. B, Lasers and optics》1995,60(2-3):129-134
Laser-cooled and trapped cesium atoms have been used as a nonlinear medium in a nearly resonant cavity. A study of the semiclassical dynamics of the system was performed, showing bistability and instabilities. In the quantum domain, squeezing in a probe beam having interacted with this system was demonstrated.Dedicated to H. Walther on the occasion of his 60th birthday 相似文献
13.
We propose a novel scheme to form a 2D dark optical surface lattice (DOSL) for cold atoms on the surface of the dense flint glass by using two sets of blue-detuned evanescent wave interference fields and a blue-detuned evanescent wave field. In the 2D DOSL, cold atoms will be trapped in the vicinity of minimum intensity and suffered the minimal light shift as well as the lowest coherence loss. The total potential and trap-depth of the individual optical micro-trap in the 2D DOSL are high enough to trap cold atoms (T = 120 μK) released from the standard magneto-optical trap (MOT), and atoms trapped in the 2D DOSL can be cooled to several μK with the efficient intensity-gradient Sisyphus cooling. The lattice constant of the DOSL can be controllable by changing the incident angles of lights. 相似文献
14.
Shi-Biao Zheng 《Optics Communications》2007,278(2):345-349
We propose an efficient scheme for realizing squeezing for a cavity mode. In the scheme, a collection of ladder-type three-level atoms are trapped in a cavity and driven by two classical fields. Under certain conditions, the cavity field deterministically evolves to a squeezed state. The scheme can also be used for conditional generation of superpositions of different squeezed vacuum states. 相似文献
15.
Scheme for Concentration of Unknown Greeberger-Horne-Zeilinger Entangled States via Cavity Decay
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We present a scheme for entanglement concentration of an unknown atomic non-maximally entangled GHZ state via cavity decay. In the scheme, the atom trapped in a cavity is manipulated by laser field, so the maximally entangled GHZ state can be obtained by performing certain operation, which can be realized by illuminating the atom in a cavity. Our method is robust against spontaneous atomic decay. 相似文献
16.
A potential scheme is proposed for generating cluster states of many trapped ions in thermal motion, in which the effective Hamiltonian does not involve the external degree of freedom and thus the scheme is insensitive to the external state, allowing it to be thermal state. The required experimental techniques of the schemes are within the scope that can be obtained in the ion-trap setup. 相似文献
17.
Evaporative cooling of trapped atoms is described as a sequence of truncation of the high-energy tail of the thermal distribution followed by collisional relaxation. This model is solved analytically for arbitrary power-law potentials. The threshold density for accelerated evaporation is. found to be lowest in a three-dimensional linear potential.Dedicated to H. Walther on the occasion of his 60th birthday 相似文献
18.
We investigate the ultrafast control of coherent population transfer in a Λ-type three-level system with a train of pump-Stokes femtosecond pulse pairs, where the pulse sequences can be produced either by optical delay line or by pulse shaping with sinusoidal phase modulation. It is shown that when the pump and Stokes pulses in each pair are applied in the counterintuitive order, similar to that in the stimulated Raman adiabatic passage technique, due to temporal quantum interference (besides optical interference in the case of overlapped subpulses), ultrafast control of coherent population transfer can be achieved by scanning the inter-pair time delay or by changing the sinusoidal phase modulation parameters. This method has potential applications in ultrafast control of chemical reactions and quantum information processing. 相似文献
19.
A scheme is presented for the cavities. In the scheme, each a coherent state with a small generation of entangled states for two atomic ensembles trapped in two distant atomic sample is initially in a Bloch state and the cavity mode is initially in amplitude. The dispersive dependent phase shift on the atomic system. The detection atomic samples collapse to an entangled Bloch state. atom-cavity interaction leads to a photon-number of a photon leaking from the cavities makes the two 相似文献
20.
Richard Friedberg 《Physics letters. A》2008,372(23):4164-4176
We compute the eigenmodes of collective emission from multi-slice slab configurations, using the transfer matrix formalism. We elucidate within this formalism the phenomena of “Invisible Gaps” in multiple-slice configuration and of “Precocious Superradiance” in periodic structures previously observed in numerical solutions of Maxwell-Bloch equations. 相似文献