Effect of three-body loss on itinerant ferromagnetism in an atomic Fermi gas

Journal Article · Fri Apr 15 04:00:00 EDT 2011 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.83.043618· OSTI ID:21544679

Conduit, G J ^[1]; Altman, E ^[1]

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1. Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 76100 (Israel)

A recent experiment has provided tentative evidence for itinerant ferromagnetism in an ultracold atomic gas. However, the interpretation of the results is complicated by significant atom losses. We argue that during the loss process the system gradually heats up but remains in local equilibrium.To quantify the consequences of atom loss on the putative ferromagnetic transition we adopt an extended Hertz-Millis theory. The losses damp quantum fluctuations, thus increasing the critical interaction strength needed to induce ferromagnetism and revert the transition from being first order to second order. This effect may resolve a discrepancy between the experiment and previous theoretical predictions. We further illuminate the impact of loss by studying the collective spin excitations in the ferromagnet. Even in the fully polarized state, where loss is completely suppressed, spin waves acquire a decay rate proportional to the three-body loss coefficient.

• OSTI ID: 21544679
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 4 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
ATOMS
DECAY
ENERGY-LEVEL TRANSITIONS
EXCITATION
FERMI GAS
FERROMAGNETISM
FLUCTUATIONS
INTERACTIONS
MAGNETISM
MANY-BODY PROBLEM
MECHANICS
PARTICLE PROPERTIES
QUANTUM MECHANICS
SPIN
SPIN WAVES
THREE-BODY PROBLEM
VARIATIONS