Elucidation and control of topological order in quantum spin liquids

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K13881
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 13030:Magnetism, superconductivity and strongly correlated systems-related
• Research Institution: Kyoto University
• Principal Investigator: Suetsugu Shota 京都大学, 理学研究科, 助教 (00893710)
• Project Period (FY): 2021-04-01 – 2023-03-31
• Keywords: 量子スピン液体 / トポロジー

Outline of Final Research Achievements

Quantum spin liquids, in which localized spins fluctuate without magnetic order or spin freezing even at absolute zero temperature, have attracted much attention because the localized spins fractionalized into different degrees of freedom, such as Majorana fermions. Although α-RuCl3 is known as a candidate material for the quantum spin liquid, it has been controversial whether the quantum spin liquid state is actually realized or not. In this project, we have demonstrated the existence of a first-order phase transition in a magnetic field by the specific heat and thermal conductivity experiments on α-RuCl3. Our results indicate the presence of the quantum spin liquid phase in α-RuCl3.

Free Research Field

物性実験

Academic Significance and Societal Importance of the Research Achievements

量子スピン液体状態で現れるマヨラナ粒子は環境ノイズに強いトポロジカル量子計算の実現に必要なため注目を集めている。本研究ではその候補物質であるα-RuCl3において確かに量子スピン液体状態が実現していることを示し、これまでの論争に決着をつけた。以上の研究成果により量子スピン液体状態の存在が確立されたため、今後はマヨラナ粒子を探索する研究がさらに加速することが期待される。