Ground state of a trapped Bose-Einstein condensate in two dimensions: Beyond the mean-field approximation

The superfine structure of Bose-Einstein condensate of alkali atoms due to the spin coupling have been investigated in the mean field approximation. In the limit of large number of atoms, we obtained the analytical solution for the fully condensed states and the states with one-atom excited. It was found that the energy of the one-atom excited state could be smaller than the energy of the fully condensed state, even two states have similar total spin.

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Two-component axionic dark matter halos

Modern Physics Letters A ◽

10.1142/s0217732320502272 ◽

2020 ◽

Vol 35 (26) ◽

pp. 2050227 ◽

Cited By ~ 1

Author(s):

Gennady P. Berman ◽

Vyacheslav N. Gorshkov ◽

Vladimir I. Tsifrinovich ◽

Marco Merkli ◽

Vladimir V. Tereshchuk

Keyword(s):

Dark Matter ◽

Ground State ◽

Mass Density ◽

Mean Field ◽

Einstein Condensate ◽

Dark Matter Halo ◽

Bose Einstein Condensate ◽

Interesting Connection ◽

Two Component ◽

Bose Einstein

We consider a two-component dark matter halo (DMH) of a galaxy containing ultra-light axions (ULA) of different mass. The DMH is described as a Bose–Einstein condensate (BEC) in its ground state. In the mean-field (MF) limit, we have derived the integro-differential equations for the spherically symmetrical wave functions of the two DMH components. We studied, numerically, the radial distribution of the mass density of ULA and constructed the parameters which could be used to distinguish between the two- and one-component DMH. We also discuss an interesting connection between the BEC ground state of a one-component DMH and Black Hole temperature and entropy, and Unruh temperature.

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MODULATION OF ORDER PARAMETER OF EXCITON BOSE-EINSTEIN CONDENSATE IN A RING

International Journal of Modern Physics B ◽

10.1142/s0217979204027475 ◽

2004 ◽

Vol 18 (27n29) ◽

pp. 3797-3802 ◽

Cited By ~ 3

Author(s):

S.-R. ERIC YANG ◽

Q-HAN PARK ◽

J. YEO

Keyword(s):

Ground State ◽

Order Parameter ◽

Weak Magnetic Field ◽

Random Potential ◽

Einstein Condensate ◽

Einstein Condensation ◽

Random Potentials ◽

Bose Einstein Condensate ◽

The Mean ◽

Bose Einstein

We have studied theoretically the Bose-Einstein condensation (BEC) of two-dimensional excitons in a ring with a random variation of the effective exciton potential along the circumference. We derive a nonlinear Gross-Pitaevkii equation (GPE) for such a condensate, which is valid even in the presence of a weak magnetic field. For several types of the random potentials our numerical solution of the ground state of the GPE displays a necklace-like structure. This is a consequence of the interplay between the random potential and a strong nonlinear repulsive term of the GPE. We have investigated how the mean distance between modulation peaks depends on properties of the random potentials.

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Transition from the mean-field to the bosonic Laughlin state in a rotating Bose-Einstein condensate

Physical Review A ◽

10.1103/physreva.100.023606 ◽

2019 ◽

Vol 100 (2) ◽

Author(s):

G. Vasilakis ◽

A. Roussou ◽

J. Smyrnakis ◽

M. Magiropoulos ◽

W. von Klitzing ◽

...

Keyword(s):

Mean Field ◽

Einstein Condensate ◽

Bose Einstein Condensate ◽

The Mean ◽

Bose Einstein

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Elementary Excitations in Trapped Bose-Einstein Condensed Gases Beyond the Mean-Field Approximation

Physical Review Letters ◽

10.1103/physrevlett.81.4541 ◽

1998 ◽

Vol 81 (21) ◽

pp. 4541-4544 ◽

Cited By ~ 74

Author(s):

L. Pitaevskii ◽

S. Stringari

Keyword(s):

Mean Field ◽

Field Approximation ◽

Mean Field Approximation ◽

Elementary Excitations ◽

The Mean ◽

Bose Einstein

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ENTANGLEMENT DYNAMICS OF FLUCTUATIONS IN TWO-MODE BOSE–EINSTEIN CONDENSATES

Modern Physics Letters B ◽

10.1142/s0217984910024924 ◽

2010 ◽

Vol 24 (25) ◽

pp. 2571-2580

Author(s):

P. L. SHU ◽

L. C. WANG ◽

X. X. YI

Keyword(s):

Time Evolution ◽

Mean Field ◽

Field Approximation ◽

Mean Field Approximation ◽

Entanglement Dynamics ◽

Weakly Coupled ◽

Tunneling Transition ◽

The Mean ◽

Bose Einstein ◽

Double Well Potential

The entanglement dynamics of fluctuations in two weakly coupled Bose–Einstein condensates (BECs) is studied in this paper. By calculating the time evolution of entanglement between two fluctuations of condensates in a double-well potential, we show that the nonlinear tunneling transition can be reflected in the entanglement dynamics of fluctuations in BECs. This complements the study on the entanglement dynamics of BECs based on the mean-field approximation.

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KINETIC ENERGY AND PHASE SEPARATION IN A DOPED ANTIFERROMAGNET

Modern Physics Letters B ◽

10.1142/s0217984995001625 ◽

1995 ◽

Vol 09 (24) ◽

pp. 1623-1629 ◽

Cited By ~ 2

Author(s):

XIN XU ◽

YUN SONG ◽

SHIPING FENG

Keyword(s):

Phase Separation ◽

Kinetic Energy ◽

Ground State ◽

Mean Field ◽

Field Approximation ◽

Mean Field Approximation ◽

Numerical Result ◽

The Mean ◽

State Kinetic

The ground-state kinetic energy of the t-J model is studied within the mean field approximation by using the fermion-spin transformation, the results show that the mean field ground-state kinetic energy is close to the numerical result at under dopings, and roughly consistent with the numerical result at optimal dopings. It is also shown that the frustration term J′ is favourable to diminish the range of the phase seperation in the t-J model.

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STABILITY OF BOSE-EINSTEIN CONDENSATES IN A PT-SYMMETRIC DOUBLE-δ POTENTIAL CLOSE TO BRANCH POINTS

Acta Polytechnica ◽

10.14311/ap.2014.54.0133 ◽

2014 ◽

Vol 54 (2) ◽

pp. 133-138 ◽

Cited By ~ 6

Author(s):

Andreas Löhle ◽

Holger Cartarius ◽

Daniel Haag ◽

Dennis Dast ◽

Jörg Main ◽

...

Keyword(s):

Ground State ◽

Mean Field ◽

Einstein Condensate ◽

Pitaevskii Equation ◽

Branch Points ◽

Mean Field Limit ◽

Bose Einstein Condensate ◽

Stability Change ◽

The Difference ◽

Bose Einstein

A Bose-Einstein condensate trapped in a double-well potential, where atoms are incoupled to one side and extracted from the other, can in the mean-field limit be described by the nonlinear Gross-Pitaevskii equation (GPE) with a PT symmetric external potential. If the strength of the in- and outcoupling is increased two PT broken states bifurcate from the PT symmetric ground state. At this bifurcation point a stability change of the ground state is expected. However, it is observed that this stability change does not occur exactly at the bifurcation but at a slightly different strength of the in-/outcoupling effect. We investigate a Bose-Einstein condensate in a PT symmetric double-δ potential and calculate the stationary states. The ground state’s stability is analysed by means of the Bogoliubov-de Gennes equations and it is shown that the difference in the strength of the in-/outcoupling between the bifurcation and the stability change can be completely explained by the norm-dependency of the nonlinear term in the Gross-Pitaevskii equation.

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