Ground state properties of Ising chain with random monomer-dimer couplings

TL;DR

This paper analytically investigates the ground state properties of a one-dimensional Ising chain with correlated random couplings, revealing how magnetization behavior varies with disorder correlations and identifying critical fields where magnetization jumps disappear.

Contribution

It introduces correlated disorder in the Ising chain and analyzes its impact on ground state magnetization, providing new insights into disorder effects on magnetic properties.

Findings

Magnetization behavior differs from the uncorrelated binary model.

Magnetization jumps vanish at certain critical fields depending on dimer types.

Ground state spin configurations explain the observed phenomena.

Abstract

We study analytically the one-dimensional Ising model with a random binary distribution of ferromagnetic and antiferromagnetic exchange couplings at zero temperature. We introduce correlations in the disorder by assigning a dimer of one type of coupling with probability $x$, and a monomer of the other type with probability $1-x$. We find that the magnetization behaves differently from the original binary model. In particular, depending on which type of coupling comes in dimers, magnetization jumps vanish at a certain set of critical fields. We explain the results based on the structure of ground state spin configuration.