LT-scaling in depleted quantum spin ladders

TL;DR

This paper investigates how non-magnetic impurities induce confinement effects in depleted quantum spin ladders, revealing a new length scale that causes universal LT scaling in susceptibilities, supported by simulations and experiments.

Contribution

It introduces a novel length scale in depleted spin ladders and demonstrates universal LT scaling, combining experimental, numerical, and analytical approaches.

Findings

Discovery of a new characteristic length L due to impurities.

Universal LT scaling of susceptibilities observed.

Excellent agreement between simulations and experimental phase diagrams.

Abstract

Using a combination of neutron scattering, calorimetry, Quantum Monte Carlo (QMC) simulations and analytic results we uncover confinement effects in depleted, partially magnetized quantum spin ladders. We show that introducing non-magnetic impurities into magnetized spin ladders leads to the emergence of a new characteristic length L in the otherwise scale-free Tomonaga-Luttinger liquid (serving as the effective low-energy model). This results in universal LT scaling of staggered susceptibilities. Comparison of simulation results with experimental phase diagrams of prototypical spin ladder compounds DIMPY and BPCB yields excellent agreement.