Journal Article

Magnetic field induced quantum phases in a tensor network study of Kitaev magnets

Kawashima, Naoki, Chern, Li Ern, Kaneko, Ryui, Okubo, Tsuyoshi, Kim, Yong Baek, Lee, Hyun-Yong, Yamaji, Youhei

2020

Overview

Recent discovery of the half quantized thermal Hall conductivity in α -RuCl 3 , a candidate material for the Kitaev spin liquid, suggests the presence of a highly entangled quantum state in external magnetic fields. This field induced phase appears between the low field zig-zag magnetic order and the high field polarized state. Motivated by this experiment, we study possible field induced quantum phases in theoretical models of the Kitaev magnets, using the two dimensional tensor network approach or infinite tensor product states. We find various quantum ground states in addition to the chiral Kitaev spin liquid occupying a small area in the phase diagram. They form a band of emergent quantum phases in an intermediate window of external magnetic fields, somewhat reminiscent of the experiment. We discuss the implications of these results in view of the experiment and previous theoretical studies. α -RuCl 3 is a candidate Kitaev spin liquid but whether or not this is realised depends on the details of the magnetic interactions. Here, the authors use state-of-the-art numerical methods to predict that for a large parameter region the Kitaev phase is supplanted by nematic paramagnetic phases.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 639/766/119/2795 / 639/766/119/997 / Entangled states / Experiments / Humanities and Social Sciences / Magnetic fields / Magnets / Materials selection / Mathematical models / multidisciplinary / Numerical methods / Phase diagrams / Phases / Science / Science (multidisciplinary) / Spin liquid / Tensors / Two dimensional models