2008/03/11 by J. E. Thomas, Thomas, J. E.
Physics and Astronomy · #Atomic and Subatomic Physics Research #Cold Atom Physics and Bose-Einstein Condensates #FOS: Physical sciences #Other Condensed Matter (cond-mat.other) #Statistical Mechanics (cond-mat.stat-mech) #Strong Light-Matter Interactions #cond-mat.other #cond-mat.stat-mech
paper · pdf · doi:10.48550/arxiv.0803.1647
3 pages
arxiv created 2008/03/11 · openalex publication_date 2008/03/11 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Optically-trapped two-component Fermi gases near a broad Feshbach resonance exhibit universal thermodynamics, where the properties of the gas are independent of the details of the two-body scattering interactions. We present a global proof that such a universal gas obeys the virial theorem for \it any trapping potential U and any spin mixture, without assuming either the local density approximation or harmonic confinement. The total energy of the gas is given in scale invariant form by E=<ε∂ U/∂ε>, where ε is an \it arbitrary energy scale in terms of which all length and energy scales that appear in the confining potential are written. This result enables model-independent energy measurement in traps that are anharmonic as well as anisotropic by observing only the cloud profile, and provides a consistency check for many-body calculations in the universal regime.