The nontrivial band topologies protected by certain symmetries have attracted significant interest in condensed matter physics.The discoveries of nontrivial topological phases in real materials provide a series of arc...The nontrivial band topologies protected by certain symmetries have attracted significant interest in condensed matter physics.The discoveries of nontrivial topological phases in real materials provide a series of archetype materials to further explore the topological physics.展开更多
Two-dimensional(2D)topological insulators present a special phase of matter manifesting unique electronic properties.Till now,many monolayer binary compounds of Sb element,mainly with a honeycomb lattice,have been rep...Two-dimensional(2D)topological insulators present a special phase of matter manifesting unique electronic properties.Till now,many monolayer binary compounds of Sb element,mainly with a honeycomb lattice,have been reported as 2D topological insulators.However,research of the topological insulating properties of the monolayer Sb compounds with square lattice is still lacking.Here,by means of the first-principles calculations,a monolayer SbI with square lattice is proposed to exhibit the tunable topological properties by applying strain.At different levels of the strain,the monolayer SbI shows two different structural phases:buckled square structure and buckled rectangular structure,exhibiting attracting topological properties.We find that in the buckled rectangular phase,when the strain is greater than 3.78%,the system experiences a topological phase transition from a nontrivial topological insulator to a trivial insulator,and the structure at the transition point actually is a Dirac semimetal possessing two type-ⅠDirac points.In addition,the system can achieve the maximum global energy gap of 72.5 meV in the topological insulator phase,implying its promising application at room temperature.This study extends the scope of 2D topological physics and provides a platform for exploring the low-dissipation quantum electronics devices.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.12374159 and 11974076)the Key Project of Natural Science Foundation of Fujian Province,China(Grant No.2021J02012)+1 种基金the GHfund A(Grant No.202302019222)the Research Foundation of the Academy of Carbon Neutrality of Fujian Normal University,China(Grant No.TZH2022-05)。
文摘The nontrivial band topologies protected by certain symmetries have attracted significant interest in condensed matter physics.The discoveries of nontrivial topological phases in real materials provide a series of archetype materials to further explore the topological physics.
基金Supported by the National Natural Science Foundation of China(Grant Nos.11974076 and 61804030)the Key Project of Natural Science Foundation of Fujian Province(Grant No.2021J02012)。
文摘Two-dimensional(2D)topological insulators present a special phase of matter manifesting unique electronic properties.Till now,many monolayer binary compounds of Sb element,mainly with a honeycomb lattice,have been reported as 2D topological insulators.However,research of the topological insulating properties of the monolayer Sb compounds with square lattice is still lacking.Here,by means of the first-principles calculations,a monolayer SbI with square lattice is proposed to exhibit the tunable topological properties by applying strain.At different levels of the strain,the monolayer SbI shows two different structural phases:buckled square structure and buckled rectangular structure,exhibiting attracting topological properties.We find that in the buckled rectangular phase,when the strain is greater than 3.78%,the system experiences a topological phase transition from a nontrivial topological insulator to a trivial insulator,and the structure at the transition point actually is a Dirac semimetal possessing two type-ⅠDirac points.In addition,the system can achieve the maximum global energy gap of 72.5 meV in the topological insulator phase,implying its promising application at room temperature.This study extends the scope of 2D topological physics and provides a platform for exploring the low-dissipation quantum electronics devices.
基金supported by the National Natural Science Foundation of China(11974076,11925408,11921004,and 12188101)the Key Project of Natural Science Foundation of Fujian Province(2021J02012)+4 种基金the Ministry of Science and Technology of China(2018YFA0305700)the Chinese Academy of Sciences(XDB33000000 and CAS-WX2021SF-0102)the K.C.Wong Education Foundation(GJTD-2018–01)the Key Research Project of Zhejiang Lab(2021PB0AC01)supported by the Swiss National Science Foundation(200021–196966)。
