Itinerant electrons on dilute frustrated Ising lattices

TL;DR

This paper investigates how itinerant spinless fermions behave as defects in a dilute frustrated Ising lattice, revealing stripe formations and effective mass variations at low temperatures.

Contribution

It introduces a self-consistent mean-field approach to analyze coupled spin-fermion systems on frustrated lattices, highlighting new stripe patterns and low-density effects.

Findings

Stripe formations along coupling lines at low temperature

Small effective mass at low fermion density

Analysis of specific heat and effective mass behavior

Abstract

We consider itinerant spinless fermions as moving defects in a dilute two-dimensional frustrated Ising system where they occupy site vacancies. Fermions interact via local spin fluctuations and we analyze coupled self-consistent mean-field equations of the Green functions after expressing the spin and fermion operators in terms of Grassmann variables. The specific heat and effective mass are analyzed with the solutions satisfying the symmetry imposed by the coupling layout. At low temperature, we find that these solutions induce stripes along the lines of couplings with the same sign, and that a low fermion density yields a small effective mass.