Scaling Properties of Antiferromagnetic Transition in Coupled Spin Ladder Systems Doped with Nonmagnetic Impurities

TL;DR

This study investigates how interladder coupling influences the magnetic phase transition in doped spin ladder systems, revealing quantum critical behavior and power-law dependencies relevant to experimental observations.

Contribution

It combines scaling theory and quantum Monte Carlo simulations to analyze the impact of impurities and interladder coupling on magnetic criticality in spin ladders.

Findings

Critical properties are governed by the quantum critical point of the undoped system.

Magnetic properties exhibit power-law dependence on impurity concentration.

Results are relevant for interpreting experimental data on ladder compounds.

Abstract

We study effects of interladder coupling on critical magnetic properties of spin ladder systems doped with small concentrations of nonmagnetic impurities, using the scaling theory together with quantum Monte Carlo (QMC) calculations. Scaling properties in a wide region in the parameter space of the impurity concentration x and the interladder coupling are governed by the quantum critical point (QCP) of the undoped system for the transition between antiferromagnetically ordered and spin-gapped phases. This multi-dimensional and strong-coupling region has characteristic power-law dependences on x for magnetic properties such as the N\'eel temperature. The relevance of this criticality for understanding experimental results of ladder compounds is stressed.