共查询到20条相似文献,搜索用时 687 毫秒
1.
We propose a scheme for the generation of arbitrary coherent superpositions of vortex states in Bose-Einstein condensates (BEC) using the orbital-angular-momentum states of light. We devise a scheme to generate coherent superpositions of two such counterrotating states of light using well-known experimental techniques. We show that a specially designed Raman scheme allows for transfer of the optical vortex-superposition state onto an initially nonrotating BEC. This creates an arbitrary and coherent superposition of a vortex and antivortex pair in the BEC. The ideas presented here could be extended to generate entangled vortex states, design memories for the orbital-angular-momentum states of light, and perform other quantum information tasks. Applications to inertial sensing are also discussed. 相似文献
2.
Guo Yu 《International Journal of Theoretical Physics》2012,51(9):2954-2959
We propose protocols for the entanglement swapping of distant atomic Bose-Einstein condensates using the photon entanglement states as the quantum channel. Two protocols are introduced: one is a single-photon scheme in which an entangled single-photon state serves as the quantum channel, and the other is a multi-photon scheme where an entangled coherent state of the probe lasers is used as the quantum channel. 相似文献
3.
We theoretically explore the transfer of vortex states between atomic Bose-Einstein condensates and optical pulses using ultraslow and stopped light techniques. We find shining a coupling laser on a rotating two-component ground state condensate with a vortex lattice generates a probe laser field with optical vortices. We also find that optical vortex states can be robustly stored in the atomic superfluids for times, in Rb-87 condensates, limited only by the ground state coherence time. 相似文献
4.
We propose a potentially practical scheme to generate two-atom maximally entangled states by the large-detuning interaction between two three-level ∧-type atoms and coherent optical fields. Conditioned on the results of detecting cavity field, four pairs of atomic maximally entangled states with unity fidelity and high successful probability can be prepared. We also investigate the influence of the cavity dissipation on the generated entangledstates and discuss the experimental feasibility of our scheme. 相似文献
5.
Mølmer K 《Physical review letters》2003,90(11):110403
We propose to subject two Bose-Einstein condensates to a periodic potential, so that one condensate undergoes the Mott-insulator transition to a state with precisely one atom per lattice site. We show that photoassociation of heteronuclear molecules within each lattice site is described by the quantum optical Jaynes-Cummings Hamiltonian. In analogy with studies of this Hamiltonian with cavity fields and trapped ions, we are thus able to engineer quantum optical states of atomic matter wave fields and we are able to reconstruct these states by quantum state tomography. 相似文献
6.
7.
Sias C Zenesini A Lignier H Wimberger S Ciampini D Morsch O Arimondo E 《Physical review letters》2007,98(12):120403
We report on measurements of resonantly enhanced tunneling of Bose-Einstein condensates loaded into an optical lattice. By controlling the initial conditions of our system we were able to observe resonant tunneling in the ground and the first two excited states of the lattice wells. We also investigated the effect of the intrinsic nonlinearity of the condensate on the tunneling resonances. 相似文献
8.
We investigate multiple linear optical teleportation in the Knill-Laflamme-Milburn scheme with both maximally and nonmaximally entangled states. We show that if the qubit is teleported several times via a nonmaximally entangled state, then the errors introduced in the previous teleportations can be corrected by the errors introduced in the following teleportations. This effect is so strong that it leads to another interesting phenomenon: i.e., the total probability of successful multiple linear optical teleportation is higher for nonmaximally entangled states than maximally entangled states. 相似文献
9.
10.
It is shown that strong coupling of Bose–Einstein condensates to an optical cavity can be realized experimentally. With an additional driven microwave field, we show that a highly nonlinear coupling among atoms in a Bose–Einstein condensate can be induced with the assistance of the cavity mode. With such interaction, we can investigate the generation of many body entangled states. In particularly, we show that multipartite entangled GHZ states can be obtained in such architecture with current available techniques. 相似文献
11.
12.
Bose-Einstein Condensates in a One-Dimensional Optical Lattice: from Superfluidity to Number-Squeezed States
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We study the phase coherence property of Bose-Einstein condensates confined in a one-dimensional optical lattice formed by a standing-wave laser field. The lattice depth is determined using a method of Kapitza-Dirac scattering between a condensate and a short pulse lattice potential. Condensates are then adiabatically loaded into the optical lattice. The phase coherence property of the confined condensates is reflected by the interference patterns of the expanded atomic cloud released from the optical lattice. For weak lattice, nearly all of the atoms stay in a superfluid state. However, as the lattice depth is increased, the phase coherence of the whole condensate sample is gradually lost, which confirms that the sub-condensates in each lattice well have evolved into number-squeezed states. 相似文献
13.
We propose a scheme to generate two-atom maximally entangled state in cavity quantum electrodynamies (QED). The scheme can 5e extended to generation of entangled multi-atom Dicke states if we control the interaction time of atoms with cavity modes. We use adiabatically state evolution under large atom-cavity detuning, so the scheme is insensitive to atomic spontaneous decay. The influence of cavity decay on fidelity and success probability is discussed. 相似文献
14.
15.
We present a scheme to prepare generalized coherent states in a system with two species of Bose-Einstein condensates. First, within the two-mode approximation, we demonstrate that a Schrödinger cat-like state can be dynamically generated and, by controlling the Josephson-like coupling strength, the number of coherent states in the superposition can be varied. Later, we analyze numerically the dynamics of the whole system when interspecies collisions are inhibited. Variables such as fractional population, Mandel parameter and variances of annihilation and number operators are used to show that the evolved state is entangled and exhibits sub-Poisson statistics. 相似文献
16.
We present a theoretical model to investigate the
interference of an array of Bose-Einstein condensates loaded in a
one-dimensional spin-dependent optical lattice, which is based on
an assumption that for the atoms in the entangled single-atom
state between the internal and the external degrees of freedom
each atom interferes only with itself. Our theoretical results
agree well with the interference patterns observed in a recent
experiment by Mandel et al. [Phys. Rev. Lett.
91, 010407 (2003)]. In addition, an experimental
suggestion of nonuniform phase distribution is proposed to test
further our theoretical model and prediction. The present work
shows that the entanglement of a single atom is sufficient for the
interference of the condensates confined in a spin-dependent
optical lattice and this interference is irrelevant with the
phases of individual condensates, i.e., this interference arises
only between each condensate and itself and there is no
interference effect between two arbitrary different condensates. 相似文献
17.
Coherence properties of Bose-Einstein condensates offer the potential for improved interferometric phase contrast. However, decoherence effects due to the mean-field interaction shorten the coherence time, thus limiting potential sensitivity. In this work, we demonstrate increased coherence times with number squeezed states in an optical lattice using the decay of Bloch oscillations to probe the coherence time. We extend coherence times by a factor of 2 over those expected with coherent state Bose-Einstein condensate interferometry. We observe quantitative agreement with theory both for the degree of initial number squeezing as well as for prolonged coherence times. 相似文献
18.
Scheme for purifying a general mixed entangled state and its linear optical implementation
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《中国物理 B》2015,(10)
We propose a scheme for purification of a general mixed entangled state. In this scheme, we start from a large number of general mixed entangled states and end up, after local operation and classical communication, with a smaller number of Bell diagonal states with higher entanglement. In particular, the scheme can purify one maximally entangled state from two entangled pairs prepared in a class of mixed entangled state. Furthermore we propose a linear optical implementation of the present scheme with polarization beam splitters and photon detectors. 相似文献
19.
H. F. Wang S. Zhang K. H. Yeon 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2010,56(2):271-275
We propose a practical scheme for concentrating entanglement in a
pair of unknown partially entangled three-photon W states with
only linear optics and photon detectors. In the scheme, Alice, Bob,
and Charlie at three distant parties can obtain one maximally
entangled three-photon W state with a certain success probability
from two identical partially entangled three-photon W states by
local operations and classical communication. The proposed setup is
very simple, which greatly simplifies the experimental realization
of the scheme. 相似文献
20.
J. Song Y. Xia H. S. Song B. Liu 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,50(1):91-96
We propose a scheme to generate a maximally four-dimensional
entangled state of two six-level atoms in two remote cavities. By
choosing suitable intensities and detunings of fields, atomic spontaneous radiation and photon leakage out of cavity and fibre
are efficiently suppressed. Thus, the intended state can be generated with high fidelity in the presence of decoherence. We
extend the scheme to generate an N-atom four-dimensional entangled
state. 相似文献