Instability of the Nagaoka ferromagnetic state of the U=∞ Hubbard model

Shastry, B. S. ; Krishnamurthy, H. R. ; Anderson, P. W. (1990) Instability of the Nagaoka ferromagnetic state of the U=∞ Hubbard model Physical Review B: Condensed Matter and Materials Physics, 41 (4). pp. 2375-2379. ISSN 1098-0121

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Official URL: http://prb.aps.org/abstract/PRB/v41/i4/p2375_1

Related URL: http://dx.doi.org/10.1103/PhysRevB.41.2375

Abstract

We identify a "kF instability" of the Nagaoka ferromagnetic state of the U = ∞ Hubbard model. We show rigorously that for a large enough hole concentration the ferromagnet possesses an instability with respect to overturning an up-spin electron at the Fermi surface and placing it at the bottom of a down-spin band made very narrow by correlation effects. We find a low-energy scale for spin waves in this strong-coupling limit, in the form of a spin-wave stiffness that is much smaller than its random-phase-approximation value.

Item Type:Article
Source:Copyright of this article belongs to The American Physical Society.
ID Code:50909
Deposited On:27 Jul 2011 13:15
Last Modified:18 May 2016 05:02

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