Topological materials host robust properties,unaffected by microscopic perturbations,owing to the global topological properties of the bulk electron system.Materials in which the topological invariant can be changed b...Topological materials host robust properties,unaffected by microscopic perturbations,owing to the global topological properties of the bulk electron system.Materials in which the topological invariant can be changed by easily tuning external parameters are especially sought after.Zirconium pentatelluride(ZrTe_(5))is one of a few experimentally available materials that reside close to the boundary of a topological phase transition,allowing the switching of its invariant by mechanical strain.Here,we unambiguously identify a topological insulator–metal transition as a function of strain,by a combination of ab initio calculations and direct measurements of the local charge density.Our model quantitatively describes the response to complex strain patterns found in bubbles of few layer ZrTe_(5) without fitting parameters,reproducing the mechanical deformation-dependent closing of the band gap observed using scanning tunneling microscopy.We calculate the topological phase diagram of ZrTe_(5) and identify the phase at equilibrium,enabling the design of device architectures,which exploit the topological switching characteristics of the system.展开更多
基金The work was conducted within the framework of the Topology in Nanomaterials Lendulet project,Grant No.LP2017-9/2017with support from the European H2020 GrapheneCore3 Project No.881603+3 种基金Financial support fromÉlvonal Grant KKP 138144,NKFIH OTKA grant K132869 and TKP20121 NKPA grant is also acknowledgedP.V.and L.O.acknowledge the support of the Janos Bolyai Research Scholarship the Bolyai+Scholarship of the Hungarian Academy of SciencesL.O.acknowledges financial support from NKFIH OTKA grant FK124723 and K131938L.O.and J.K.acknowledges the support from the Ministry of Innovation and Technology for the Quantum Information National Laboratory.
文摘Topological materials host robust properties,unaffected by microscopic perturbations,owing to the global topological properties of the bulk electron system.Materials in which the topological invariant can be changed by easily tuning external parameters are especially sought after.Zirconium pentatelluride(ZrTe_(5))is one of a few experimentally available materials that reside close to the boundary of a topological phase transition,allowing the switching of its invariant by mechanical strain.Here,we unambiguously identify a topological insulator–metal transition as a function of strain,by a combination of ab initio calculations and direct measurements of the local charge density.Our model quantitatively describes the response to complex strain patterns found in bubbles of few layer ZrTe_(5) without fitting parameters,reproducing the mechanical deformation-dependent closing of the band gap observed using scanning tunneling microscopy.We calculate the topological phase diagram of ZrTe_(5) and identify the phase at equilibrium,enabling the design of device architectures,which exploit the topological switching characteristics of the system.
