Electronic Topological Transition of 2D Boron by the Ion Exchange Reaction
Xiaoni Zhang, Yuki Tsujikawa, Ikuma Tateishi, Masahito Niibe, Tetsuya Wada, Masafumi Horio, Miwa Hikichi, Yasunobu Ando, Kunio Yubuta, Takahiro Kondo, Iwao Matsuda
Abstract
We systematically investigated electronic evolutions of nonsymmorphic borophene with chemical environments that were realized by the ion exchange method. Electronic structures can be characterized by the topological Z2 invariant. Spectroscopic experiments and DFT calculations unveiled that a sheet of hydrogenated borophene (borophane) is the Dirac nodal loop semimetal (Z2=−1), while a layered crystal of YCrB4 is an insulator (Z2=1). The results demonstrate the electronic topological transition by replacement of the counter atoms on the nonsymmorphic borophene layer.
Topics & Concepts
BoronElectronic structureSemimetalBoropheneMaterials scienceTopology (electrical circuits)Topological insulatorIonDirac (video compression format)Condensed matter physicsChemical physicsChemistryPhysicsOptoelectronicsSiliconQuantum mechanicsOrganic chemistryMathematicsNeutrinoCombinatoricsGraphene research and applicationsBoron and Carbon Nanomaterials ResearchDiamond and Carbon-based Materials Research