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Title: Rotons in Interacting Ultracold Bose Gases

Abstract

In three dimensions, noninteracting bosons undergo Bose-Einstein condensation at a critical temperature, T{sub c}, which is slightly shifted by {Delta}T{sub c}, if the particles interact. We calculate the excitation spectrum of interacting Bose systems, {sup 4}He and {sup 87}Rb, and show that a roton minimum emerges in the spectrum above a threshold value of the gas parameter. We provide a general theoretical argument for why the roton minimum and the maximal upward critical temperature shift are related. We also suggest two experimental avenues to observe rotons in condensates. These results, based upon a path-integral Monte Carlo approach, provide a microscopic explanation of the shift in the critical temperature and also show that a roton minimum does emerge in the excitation spectrum of particles with a structureless, short-range, two-body interaction.

Authors:
; ;  [1]
  1. Jack Dodd Centre for Quantum Technology, Department of Physics, University of Otago, Dunedin (New Zealand)
Publication Date:
OSTI Identifier:
21611792
Resource Type:
Journal Article
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 107; Journal Issue: 14; Other Information: DOI: 10.1103/PhysRevLett.107.140401; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0031-9007
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BOSE-EINSTEIN CONDENSATION; BOSE-EINSTEIN GAS; BOSONS; CRITICAL TEMPERATURE; EXCITATION; HELIUM 4; MONTE CARLO METHOD; PATH INTEGRALS; ROTONS; RUBIDIUM 87; SPECTRA; TWO-BODY PROBLEM; BETA DECAY RADIOISOTOPES; BETA-MINUS DECAY RADIOISOTOPES; CALCULATION METHODS; ENERGY-LEVEL TRANSITIONS; EVEN-EVEN NUCLEI; HELIUM ISOTOPES; INTEGRALS; INTERMEDIATE MASS NUCLEI; ISOTOPES; LIGHT NUCLEI; MANY-BODY PROBLEM; NUCLEI; ODD-EVEN NUCLEI; PHYSICAL PROPERTIES; QUASI PARTICLES; RADIOISOTOPES; RUBIDIUM ISOTOPES; STABLE ISOTOPES; THERMODYNAMIC PROPERTIES; TRANSITION TEMPERATURE; YEARS LIVING RADIOISOTOPES

Citation Formats

Cormack, Samuel C., Schumayer, Daniel, and Hutchinson, David A. W. Rotons in Interacting Ultracold Bose Gases. United States: N. p., 2011. Web. doi:10.1103/PHYSREVLETT.107.140401.
Cormack, Samuel C., Schumayer, Daniel, & Hutchinson, David A. W. Rotons in Interacting Ultracold Bose Gases. United States. doi:10.1103/PHYSREVLETT.107.140401.
Cormack, Samuel C., Schumayer, Daniel, and Hutchinson, David A. W. Fri . "Rotons in Interacting Ultracold Bose Gases". United States. doi:10.1103/PHYSREVLETT.107.140401.
@article{osti_21611792,
title = {Rotons in Interacting Ultracold Bose Gases},
author = {Cormack, Samuel C. and Schumayer, Daniel and Hutchinson, David A. W.},
abstractNote = {In three dimensions, noninteracting bosons undergo Bose-Einstein condensation at a critical temperature, T{sub c}, which is slightly shifted by {Delta}T{sub c}, if the particles interact. We calculate the excitation spectrum of interacting Bose systems, {sup 4}He and {sup 87}Rb, and show that a roton minimum emerges in the spectrum above a threshold value of the gas parameter. We provide a general theoretical argument for why the roton minimum and the maximal upward critical temperature shift are related. We also suggest two experimental avenues to observe rotons in condensates. These results, based upon a path-integral Monte Carlo approach, provide a microscopic explanation of the shift in the critical temperature and also show that a roton minimum does emerge in the excitation spectrum of particles with a structureless, short-range, two-body interaction.},
doi = {10.1103/PHYSREVLETT.107.140401},
journal = {Physical Review Letters},
issn = {0031-9007},
number = 14,
volume = 107,
place = {United States},
year = {2011},
month = {9}
}