Monte Carlo study of the spin transport in magnetic materials

Abstract

The resistivity in magnetic materials has been theoretically shown to depend on the spin-spin correlation function which in turn depends on the magnetic-field, the density of conduction electron, the magnetic ordering stability, etc. However, these theories involved a lot of approximations, so their validity remained to be confirmed. The purpose of this work is to show by newly improved extensive Monte Carlo (MC) simulation the resistivity of the spin resistivity from low-T ordered phase to high-T paramagnetic phase in ferromagnetic and antiferromagnetic films. We take into account the interaction between the itinerant spins and the localized lattice spins as well as the interaction between itinerant spins themselves. We show that in ferromagnets the resistivity shows a sharp peak at the magnetic phase transition in agreement with previous theories in spite of their numerous approximations. Resistivity in antiferromagnets on the other hand shows no peak for the SC, BCC and diamond lattices. Discussion on the origin of these resistivity behaviors is given.

Spin resistivity in frustrated antiferromagnets

“…29 ρ does not show a peak at the magnetic phase transition temperature. It shows instead a discontinuous jump at the transition temperature T C .…”

Monte Carlo study of magnetic resistivity in semiconducting MnTe

“…In doing so, we neglect the quantum effects which are of course important at very low temperature but not in the transition region at room temperature where we focus our attention. The MC technique we use for the transport is a multistep averaging which has shown to reduce efficiently statistical fluctuations 33,34 . The reader is referred to our early works for a detailed description of our method as well as the effects of changing physical parameters such as D 1 in antiferromagnets.…”

SPIN RESISTIVITY IN THE FRUSTRATED J1 - J2 MODEL

“…6 We have shown by MC simulations that this is true, however the form of the rounded peak depends on the crystal structure and other interaction parameters. 10,11 Experimentally, there has been a large number of works dealing with the spin resistivity in different magnetic compounds. 12,13,14,15,16,17,18,19,20,21,22 These experiments show the existence of an anomaly of ρ at the magnetic phase transition.…”