학술논문
Vacancy Spectroscopy of Non-Abelian Kitaev Spin Liquids.
Document Type
Academic Journal
Author
Kao WH; School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.; Perkins NB; School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.; Halász GB; Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.; Quantum Science Center, Oak Ridge, Tennessee 37831, USA.
Source
Publisher: American Physical Society Country of Publication: United States NLM ID: 0401141 Publication Model: Print Cited Medium: Internet ISSN: 1079-7114 (Electronic) Linking ISSN: 00319007 NLM ISO Abbreviation: Phys Rev Lett Subsets: PubMed not MEDLINE; MEDLINE
Subject
Language
English
Abstract
Spin vacancies in the non-Abelian Kitaev spin liquid are known to harbor Majorana zero modes, potentially enabling topological quantum computing at elevated temperatures. Here, we study the spectroscopic signatures of such Majorana zero modes in a scanning tunneling setup where a non-Abelian Kitaev spin liquid with a finite density of spin vacancies forms a tunneling barrier between a tip and a substrate. Our key result is a well-defined peak close to zero bias voltage in the derivative of the tunneling conductance whose voltage and intensity both increase with the density of vacancies. This "quasi-zero-voltage peak" is identified as the closest analog of the zero-voltage peak observed in topological superconductors that additionally reflects the fractionalized nature of spin-liquid-based Majorana zero modes. We further highlight a single-fermion Van Hove singularity at a higher voltage that reveals the energy scale of the emergent Majorana fermions in the Kitaev spin liquid. Our proposed signatures are within reach of current experiments on the candidate material α-RuCl_{3}.