9904058v1

related topics
{time, wave, function}
{state, states, coherent}
{time, decoherence, evolution}
{group, space, representation}
{level, atom, field}
{temperature, thermal, energy}
{cos, sin, state}
{cavity, atom, atoms}
{equation, function, exp}
{trap, ion, state}
{vol, operators, histories}
{information, entropy, channel}
{states, state, optimal}
{state, states, entangled}
{force, casimir, field}

Wigner functions, squeezing properties and slow decoherence of atomic Schrodinger cats

M. G. Benedict, A. Czirjak

abstract: We consider a class of states in an ensemble of two-level atoms: a superposition of two distinct atomic coherent states, which can be regarded as atomic analogues of the states usually called Schrodinger cat states in quantum optics. According to the relation of the constituents we define polar and nonpolar cat states. The properties of these are investigated by the aid of the spherical Wigner function. We show that nonpolar cat states generally exhibit squeezing, the measure of which depends on the separation of the components of the cat, and also on the number of the constituent atoms. By solving the master equation for the polar cat state embedded in an external environment, we determine the characteristic times of decoherence, dissipation and also the characteristic time of a new parameter, the non-classicality of the state. This latter one is introduced by the help of the Wigner function, which is used also to visualize the process. The dependence of the characteristic times on the number of atoms of the cat and on the temperature of the environment shows that the decoherence of polar cat states is surprisingly slow.

oai_identifier:
oai:arXiv.org:quant-ph/9904058
categories:
quant-ph
comments:
RevTeX, 14 pages including 8 PostScript figures. High quality versions of Figures 1, 3, 5, 7 and 8 are available at http://www.jate.u-szeged.hu/~benedict/asc_figures.html . (Submitted to Physical Review A: March 26, 1999.)
doi:
10.1103/PhysRevA.60.4034
arxiv_id:
quant-ph/9904058
journal_ref:
Phys.Rev. A60 (1999) 4034
created:
1999-04-14

Full article ▸

related documents
0301148v1
0212132v1
0006041v1
0302046v1
0404084v1
9902039v2
0207067v3
9807043v1
0307006v1
0106165v1
0602236v1
0301068v1
0512108v1
0607098v2
9901001v1
0006110v1
0502079v1
0109053v1
0106020v1
9910101v1
0206177v1
0206043v1
0209004v2
0210009v1
0211055v1