Effect of temperature on quantum criticality in the frustrated two-leg Heisenberg ladder

Abstract

The antiferromagnetic Heisenberg model on the two-leg ladder with exchange interactions along the chains, rungs, and diagonals is studied using the Jordan-Wigner transformation and bond-mean-field theory. The inclusion of all three couplings introduces frustration to the system and depending on their relative strengths the ladder can adopt one of three possible magnetically-disordered gapped states. The phase diagram found in this mean-field approach is in very good agreement with the one calculated by Weihong and colleagues using the Lanczos exact diagonalization method. By analyzing the ground-state energy we study quantum criticality when the coupling parameters are varied at zero temperature. We study the effect of temperature on the phase boundaries, and find that the system shows thermally-induced criticality for some values of the rung and diagonal coupling constants. All the phase transitions encountered in this system occur between disordered phases, and are all caused by frustration.

12 pages, 19 figures

References in corpus (2)

• Search for quantum dimer phases and transitions in a frustrated spin ladder
• Energy-level ordering and ground-state quantum numbers for frustrated two-leg spin-1/2 ladder model

Cited by in corpus (4)

• Quantum phase transitions in the exactly solved spin-1/2 Heisenberg-Ising ladder
• Antiferromagnetic ordering of energy levels for spin ladder with four-spin cyclic exchange: Generalization of the Lieb-Mattis theorem
• Quantum and classical criticalities in the frustrated two-leg Heisenberg ladder
• Interplay between field-induced and frustration-induced quantum criticalities in the frustrated two-leg Heisenberg ladder