Phase Diagram of a Spin Ladder with Cyclic Four Spin Exchange

TL;DR

This paper maps out the phase diagram of a spin ladder model with cyclic four-spin exchange, revealing six distinct phases and analyzing the nature of phase transitions using advanced numerical methods.

Contribution

It provides the first comprehensive phase diagram of the $S=1/2$ Heisenberg ladder with cyclic four-spin exchange, identifying six phases and characterizing their transitions.

Findings

Six different phases identified, including rung singlet and ferromagnetic.

Two symmetry-broken phases with staggered dimers and scalar chiralities.

Phase transitions localized and their nature investigated.

Abstract

We present the phase diagram of the $S=1/2$ Heisenberg model on the two leg ladder with cyclic four spin exchange, determined by a combination of Exact Diagonalization and Density Matrix Renormalization Group techniques. We find six different phases and regimes: the rung singlet phase, a ferromagnetic phase, two symmetry broken phases with staggered dimers and staggered scalar chiralities, and a gapped region with dominant vector chirality or collinear spin correlations. We localize the phase transitions and investigate their nature.