Itinerant ferromagnetism in an interacting Fermi gas with mass imbalance

Journal Article · Sun May 15 00:00:00 EDT 2011 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.83.053625· OSTI ID:21546838

Keyserlingk, C W. von ^[1]; Conduit, G J ^[2]

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1. Rudolf Peierls Centre for Theoretical Physics, 1 Keble Road, Oxford OX1 3NP (United Kingdom)
2. Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 76100 (Israel)

We study the emergence of itinerant ferromagnetism in an ultracold atomic gas with a variable mass ratio between the up- and down-spin species. Mass imbalance breaks the SU(2) spin symmetry, leading to a modified Stoner criterion. We first elucidate the phase behavior in both the grand canonical and canonical ensembles. Second, we apply the formalism to a harmonic trap to demonstrate how a mass imbalance delivers unique experimental signatures of ferromagnetism. These could help future experiments to better identify the putative ferromagnetic state. Furthermore, we highlight how a mass imbalance suppresses the three-body loss processes that handicap the formation of a ferromagnetic state. Finally, we study the time-dependent formation of the ferromagnetic phase following a quench in the interaction strength.

• OSTI ID: 21546838
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 5 Vol. 83; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANGULAR MOMENTUM
FERMI GAS
FERROMAGNETISM
HARMONIC POTENTIAL
INTERACTIONS
LIE GROUPS
MAGNETISM
MANY-BODY PROBLEM
MASS
NUCLEAR POTENTIAL
PARTICLE PROPERTIES
POTENTIALS
SPIN
SU GROUPS
SYMMETRY GROUPS
THREE-BODY PROBLEM
TIME DEPENDENCE
TRAPS