Large Spin Formation and Thermodynamic Properties of Disordered Spin Ladders with Site Dilution

TL;DR

This paper investigates how site dilution and bond randomness affect the low-temperature magnetic properties of disordered two-leg spin-1/2 ladders, revealing a universal large spin phase with Curie-like susceptibility behavior.

Contribution

It demonstrates that nonzero doping induces a large spin phase in disordered spin ladders, with universal susceptibility behavior regardless of randomness strength.

Findings

Systems exhibit a large spin phase at nonzero doping.

Susceptibility shows universal Curie-like 1/T behavior.

Similar behavior observed in ladders doped with spin-1 impurities.

Abstract

Low temperature properties of antiferromagnetic two-leg spin-1/2 ladders with bond randomness and site dilution (or doping with nonmagnetic impurities) are studied using the real-space renormalization-group technique. We find that for non zero doping concentrations the systems are driven into a phase dominated by large effective spins, i.e. the Large Spin phase. The susceptibility follows a universal Curie-like 1/T behavior at low temperature,regardless of the doping concentrations (as long as it is nonzero) and the strength of bond randomness. Very similar behavior has been found in ladders that are doped with magnetic impurities that carry spin-1.