Magnetic Field Induced Ordering in Quasi-One-Dimensional Quantum Magnets

TL;DR

This paper investigates how external magnetic fields induce three-dimensional magnetic order in anisotropic quantum magnets, especially in systems with higher spins, by analyzing the suppression of quantum fluctuations and the resulting ordering transitions.

Contribution

It provides a theoretical framework for understanding magnetic ordering transitions driven by magnetic fields in strongly anisotropic quantum magnets, including complex N-leg spin ladders.

Findings

Magnetic fields can induce 3D magnetic order in quasi-1D systems.

Higher spin systems exhibit cascades of ordering transitions.

Quantum fluctuations are suppressed at high magnetic fields, raising the ordering temperature.

Abstract

Three-dimensional magnetic ordering transitions are studied theoretically in strongly anisotropic quantum magnets. An external magnetic field can drive quasi-one-dimensional subsystems with a spin gap into a gapless regime, thus inducing long-range three-dimensional magnetic ordering due to weak residual magnetic coupling between the subsystems. Compounds with higher spin degrees of freedom, such as N-leg spin-1/2 ladders, are shown to have cascades of ordering transitions. At high magnetic fields, zero-point fluctuations within the quasi-1D subsystems are suppressed, causing quantum corrections to the ordering temperature to be reduced.