Itinerant Ferromagnetism of a Repulsive Atomic Fermi Gas: A Quantum Monte Carlo Study

Journal Article · Fri Jul 16 00:00:00 EDT 2010 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.105.030405· OSTI ID:21410912

Pilati, S; Troyer, M ^[1]; Bertaina, G; Giorgini, S ^[2]

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1. Theoretische Physik, ETH Zurich, CH-8093 Zurich (Switzerland)
2. Dipartimento di Fisica, Universita di Trento and INO-CNR BEC Center , I-38050 Povo, Trento (Italy)

We investigate the phase diagram of a two-component repulsive Fermi gas at T=0 by means of quantum Monte Carlo simulations. Both purely repulsive and resonant attractive model potentials are considered in order to analyze the limits of the universal regime where the details of interatomic forces can be neglected. The equation of state of both balanced and unbalanced systems is calculated as a function of the interaction strength and the critical density for the onset of ferromagnetism is determined. The energy of the strongly polarized gas is calculated and parametrized in terms of the physical properties of repulsive polarons, which are relevant for the stability of the fully ferromagnetic state. Finally, we analyze the phase diagram in the interaction-polarization plane under the assumption that only phases with homogeneous magnetization can be produced.

• OSTI ID: 21410912
• Journal Information: Physical Review Letters, Vol. 105, Issue 3; Other Information: DOI: 10.1103/PhysRevLett.105.030405; (c) 2010 The American Physical Society; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
36 MATERIALS SCIENCE
COMPUTERIZED SIMULATION
DENSITY
EQUATIONS OF STATE
FERMI GAS
FERROMAGNETISM
INTERACTIONS
INTERATOMIC FORCES
MAGNETIZATION
MONTE CARLO METHOD
PHASE DIAGRAMS
POLARIZATION
POTENTIALS
STABILITY
CALCULATION METHODS
DIAGRAMS
EQUATIONS
INFORMATION
MAGNETISM
PHYSICAL PROPERTIES
SIMULATION