skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Enhanced quantum spin fluctuations in a binary Bose-Einstein condensate

Authors:
; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1419098
Grant/Contract Number:
DEAC52-06NA25396
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Physical Review A
Additional Journal Information:
Journal Volume: 97; Journal Issue: 2; Related Information: CHORUS Timestamp: 2018-02-01 10:18:19; Journal ID: ISSN 2469-9926
Publisher:
American Physical Society
Country of Publication:
United States
Language:
English

Citation Formats

Bisset, R. N., Kevrekidis, P. G., and Ticknor, C. Enhanced quantum spin fluctuations in a binary Bose-Einstein condensate. United States: N. p., 2018. Web. doi:10.1103/PhysRevA.97.023602.
Bisset, R. N., Kevrekidis, P. G., & Ticknor, C. Enhanced quantum spin fluctuations in a binary Bose-Einstein condensate. United States. doi:10.1103/PhysRevA.97.023602.
Bisset, R. N., Kevrekidis, P. G., and Ticknor, C. 2018. "Enhanced quantum spin fluctuations in a binary Bose-Einstein condensate". United States. doi:10.1103/PhysRevA.97.023602.
@article{osti_1419098,
title = {Enhanced quantum spin fluctuations in a binary Bose-Einstein condensate},
author = {Bisset, R. N. and Kevrekidis, P. G. and Ticknor, C.},
abstractNote = {},
doi = {10.1103/PhysRevA.97.023602},
journal = {Physical Review A},
number = 2,
volume = 97,
place = {United States},
year = 2018,
month = 2
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on February 1, 2019
Publisher's Accepted Manuscript

Save / Share:
  • We investigate the effects of thermal and quantum fluctuations on the phase diagram of a spin-1 {sup 87}Rb Bose-Einstein condensate (BEC) under the quadratic Zeeman effect. Due to the large ratio of spin-independent to spin-dependent interactions of {sup 87}Rb atoms, the effect of noncondensed atoms on the condensate is much more significant than that in scalar BECs. We find that the condensate and spontaneous magnetization emerge at different temperatures when the ground state is in the broken-axisymmetry phase. In this phase, a magnetized condensate induces spin coherence of noncondensed atoms in different magnetic sublevels, resulting in temperature-dependent magnetization of themore » noncondensate. We also examine the effect of quantum fluctuations on the order parameter at absolute zero and find that the ground-state phase diagram is significantly altered by quantum depletion.« less
  • We study the drag force acting on an impurity moving through a 1D Bose-Einstein condensate in the presence of both quantum and thermal fluctuations. We are able to find exact analytical solutions of the partial differential equations to the level of the Bogoliubov approximation. At zero temperature, we find a nonzero force is exerted on the impurity at subcritical velocities, due to the scattering of quantum fluctuations. We make the following explicit assumptions: far from the impurity the system is in a quantum state given by that of a zero (or finite) temperature Bose-Einstein condensate, and the scattering process generatesmore » only causally related reflection/transmission. The results raise unanswered questions in the quantum dynamics associated with the formation of persistent currents.« less
  • We present a quantum description of the interaction between a Bose-Einstein condensate and a single-mode quantized radiation field in the presence of a strong far-off-resonant pump laser. In the linear regime, the atomic medium is described approximately by two momentum states coupled to the radiation mode. We calculate the evolution of the operators in the Heisenberg picture and their expectation values, such as average and variance of the occupation numbers, atom-atom and atom-field correlations, and two-mode squeezing parameters. Then, we disentangle the evolution operator and obtain the exact evolution of the state vector in the linear regime. This allows usmore » to demostrate that the system can be atom-atom or atom-field thermally entangled. We define the quasiclassical and the quantum recoil limits, for which explicit expressions of the average population numbers are obtained.« less
  • We calculate a force due to zero-temperature quantum fluctuations on a stationary object in a moving superfluid flow. We model the object by a localized potential varying only in the flow direction and model the flow by a three-dimensional weakly interacting Bose-Einstein condensate at zero temperature. We show that this force exists for any arbitrarily small flow velocity and discuss the implications for the stability of superfluid flow.
  • We consider the self-localization of neutral impurity atoms in a Bose-Einstein condensate in a one-dimensional model. Within the strong coupling approach, we show that the self-localized state exhibits parametric soliton behavior. The corresponding stationary states are analogous to the solitons of nonlinear optics and to the solitonic solutions of the Schroedinger-Newton equation (which appears in models that consider the connection between quantum mechanics and gravitation). In addition, we present a Bogoliubov-de Gennes formalism to describe the quantum fluctuations around the product state of the strong coupling description. Our fluctuation calculations yield the excitation spectrum and reveal considerable corrections to themore » strong coupling description. The knowledge of the spectrum allows a spectroscopic detection of the impurity self-localization phenomenon.« less