Exact, closed expressions are obtained for the perpendicular and parallel susceptibilities of the one-dimensional spin-1/2 Ising model (i) with nearest neighbor interactions in a uniform magnetic field and (ii) with next-nearest neighbor interactions but without the magnetic field, in the thermodynamic limit. Graphs of the susceptibilities as a function of temperature for various magnetic field strengths in (i), and as a function of different ratios of the interaction strengths in (ii), are discussed.Exact, closed expressions are obtained for the perpendicular and parallel susceptibilities of the one-dimensional spin-1/2 Ising model (i) with nearest neighbor interactions in a uniform magnetic field and (ii) with next-nearest neighbor interactions but without the magnetic field, in the thermodynamic limit. Graphs of the susceptibilities as a function of temperature for various magnetic field strengths in (i), and as a function of different ratios of the interaction strengths in (ii), are discussed.

Journal of Mathematical PhysicsMay 1, 197412 citations

Magnetic properties of ideal quantum gases

S. Goulart Rosa

Jan 1, 19731 citation

Fluctuation susceptibility of ultracold bosons in the vicinity of condensation in the presence of an artificial magnetic field

Arvid J. Kingl, Dimitri M. Gangardt, Igor V. Lerner

We study the behavior of ultracold bosonic gases in the critical region above the Bose-Einstein condensation in the presence of an artificial magnetic field, ${B}_{\mathrm{art}}$ . We show that the condensate fluctuations above the critical temperature ${T}_{\mathrm{c}}$ cause the fluctuational susceptibility, ${\ensuremath{\chi}}_{\mathrm{fl}}$, of a uniform gas to have a stronger power-law divergence than in an analogous superconducting system. Measuring such a divergence opens new ways of exploring critical properties of ultracold gases and an opportunity for an accurate determination of ${T}_{\mathrm{c}}$ . We describe a method of measuring ${\ensuremath{\chi}}_{\mathrm{fl}}$ which requires a constant gradient in ${B}_{\mathrm{art}}$ and suggest a way of creating such a field in experiment.We study the behavior of ultracold bosonic gases in the critical region above the Bose-Einstein condensation in the presence of an artificial magnetic field, ${B}_{\mathrm{art}}$. We show that the condensate fluctuations above the critical temperature ${T}_{\mathrm{c}}$ cause the fluctuational susceptibility, ${\ensuremath{\chi}}_{\mathrm{fl}}$, of a uniform gas to have a stronger power-law divergence than in an analogous superconducting system. Measuring such a divergence opens new ways of exploring critical properties of ultracold gases and an opportunity for an accurate determination of ${T}_{\mathrm{c}}$. We describe a method of measuring ${\ensuremath{\chi}}_{\mathrm{fl}}$ which requires a constant gradient in ${B}_{\mathrm{art}}$ and suggest a way of creating such a field in experiment.

arXiv:1506.04053Physical Review AApr 15, 20160 citations

Magnetic correlations and density ordering in quantum gases

Tilman Esslinger

Bulletin of the American Physical SocietyMar 21, 20130 citations

Spin-polarized Fermi Gases

Лев П. Питаевский, S. Stringari

Abstract This chapter discusses the magnetic properties of interacting Fermi gases. It considers the transition to the ferromagnetic phase (itinerant ferromagnetism) of a repulsive Fermi gas as a consequence of the Stoner instability. The dependence of the magnetic susceptibility on the relevant interaction coupling constant is explicitly discussed. The chapter then investigates the competition between superfluidity and ferromagnetism and the nature of the Clogston–Chandrasekhar transition, both in uniform and harmonically trapped Fermi gases, with special focus on the behaviour at unitarity, where systematic experimental data are available. It finally addresses the problem of the polaron in highly polarized configurations and the transition from the polaron to molecular binding along the BCS–BEC crossover.Abstract This chapter discusses the magnetic properties of interacting Fermi gases. It considers the transition to the ferromagnetic phase (itinerant ferromagnetism) of a repulsive Fermi gas as a consequence of the Stoner instability. The dependence of the magnetic susceptibility on the relevant interaction coupling constant is explicitly discussed. The chapter then investigates the competition between superfluidity and ferromagnetism and the nature of the Clogston–Chandrasekhar transition, both in uniform and harmonically trapped Fermi gases, with special focus on the behaviour at unitarity, where systematic experimental data are available. It finally addresses the problem of the polaron in highly polarized configurations and the transition from the polaron to molecular binding along the BCS–BEC crossover.

Jan 1, 20160 citations

We study the behavior of ultracold bosonic gases in the critical region above the Bose-Einstein condensation in the presence of an artificial magnetic field,

{B}_{\mathrm{art}}

. We show that the condensate fluctuations above the critical temperature

{T}_{\mathrm{c}}

cause the fluctuational susceptibility, ${\ensuremath{\chi}}_{\mathrm{fl}}$, of a uniform gas to have a stronger power-law divergence than in an analogous superconducting system. Measuring such a divergence opens new ways of exploring critical properties of ultracold gases and an opportunity for an accurate determination of

{T}_{\mathrm{c}}

. We describe a method of measuring ${\ensuremath{\chi}}_{\mathrm{fl}}$ which requires a constant gradient in

{B}_{\mathrm{art}}

and suggest a way of creating such a field in experiment.