Department of Physics, Kyungpook National University
경북대학교 물리학과

KNU Physics Seminars

Identification of Kitaev Quantum Spin Liquids via Topological Phase Transition

by 은국 문 (KAIST)

320호 (219동)




2022년 물리학과 양자 물성 세미나

Quantum spin liquids realize the enormous entanglement of quantum magnets and are suggested as a candidate platform for future quantum science and technology. In particular, topological quantum computations are suggested in the non-abelian phase of Kitaev quantum spin liquid with Majorana fermions and the detection of Majorana fermions is one of the most outstanding problems in modern condensed matter physics. Here, we propose a concrete way to identify the non-abelian Kitaev quantum spin liquid by using topological phase transitions. Topologically protected critical lines exist on a plane of magnetic field angles, and their shapes are determined by microscopic spin interactions. A chirality operator plays a key role in demonstrating the microscopic dependences of the critical lines. We also show that the chirality operator can be used to evaluate the topological properties of the non-abelian Kitaev quantum spin liquid without relying on Majorana fermion descriptions. Experimental criteria for the non-abelian spin liquid state are provided for experiments.