Dynamical CPA approach to an itinerant fermionic spin glass model

Abstract

We study a fermionic version of the Sherrington-Kirkpatrick model including nearest-neighbor hopping on a $\infty$-dimensional simple cubic lattices. The problem is reduced to one of free fermions moving in a dynamical effective random medium. By means of a CPA method we derive a set of self-consistency equations for the spin glass order parameter and for the Fourier components of the local spin susceptibility. In order to solve these equations numerically we employ an approximation scheme which restricts the dynamics to a feasible number of the leading Fourier components. From a sequence of systematically improved dynamical approximations we estimate the location of the quantum critical point.

arXiv comment9 pages, 6 figures, revised version

References in corpus (6)

• Non-Fermi liquid regime of a doped Mott insulator
• Spatial Correlations in Dynamical Mean Field Theory
• Quantum field theory of metallic spin glasses
• Magnetic Gaps related to Spin Glass Order in Fermionic Systems
• Tricritical behaviour of Ising spin glasses with charge fluctuations
• Low-energy excitations in fermionic spin glasses: A quantum-dynamical image of Parisi symmetry breaking

Cited by in corpus (2)

• Dynamical solutions of a quantum Heisenberg spin glass model
• Construction and purpose of effective field theories for frustrated magnetic order