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

G. J. Conduit and E. Altman
Phys. Rev. A 83, 043618 – Published 20 April 2011

Abstract

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.

  • Figure
  • Figure
  • Figure
  • Received 15 November 2009

DOI:https://doi.org/10.1103/PhysRevA.83.043618

©2011 American Physical Society

Authors & Affiliations

G. J. Conduit1,2,* and E. Altman1

  • 1Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 76100, Israel
  • 2Physics Department, Ben Gurion University, Beer Sheva 84105, Israel

  • *gjc29@cam.ac.uk

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 83, Iss. 4 — April 2011

Reuse & Permissions
Access Options
CHORUS

Article Available via CHORUS

Download Accepted Manuscript
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review A

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×