Topological insulating states in 2-dimensional(2D)materials are ideal systems to study different types of quantized response signals due to their in gap metallic states.Very recently,the quantum spin Hall effect was d...Topological insulating states in 2-dimensional(2D)materials are ideal systems to study different types of quantized response signals due to their in gap metallic states.Very recently,the quantum spin Hall effect was discovered in monolayer TalrTe Via the observation of quantized longitudinal conductance that rarely exists in other 2D topological insulators.The nontrivial Z_(2)topological charges can exist at both charge neutrality point and the van Hove singularity point with correlation-effect-induced bandgap.On the basis of this model 2D material,we studied the switch of quantized signals between longitudinal conductance and transversal Hall conductance via tuning external magnetic field.In Z_(2)topological phase of monolayer TalrTe_(4),the zero Chern number can be understood as 1-1=O from the double band inversion from spinup and spin-down channels.After applying a magnetic field perpendicular to the plane,the Zeeman split changes the band order for one branch of the band inversion from spin-up and spin-down channels,along with a sign charge of the Berry phase.Then,the net Chern number of 1-1=0 is tuned to 1+1=2 or-1-1=-2 depending on the orientation of the magnetic field.The quantized signal not only provides another effective method for the verification of topological state in monolayer TalrTe_(4)but also offers a strategy for the utilization of the new quantum topological states based on switchable quantized responses.展开更多
基金supported by the Foundation from Liaoning Province(grant no.XLYC2203080)the National Natural Science Foundation of China(grant nos.52271016 and 52188101)the National Key R&D Program of China(grant no.2021YFB3501503)。
文摘Topological insulating states in 2-dimensional(2D)materials are ideal systems to study different types of quantized response signals due to their in gap metallic states.Very recently,the quantum spin Hall effect was discovered in monolayer TalrTe Via the observation of quantized longitudinal conductance that rarely exists in other 2D topological insulators.The nontrivial Z_(2)topological charges can exist at both charge neutrality point and the van Hove singularity point with correlation-effect-induced bandgap.On the basis of this model 2D material,we studied the switch of quantized signals between longitudinal conductance and transversal Hall conductance via tuning external magnetic field.In Z_(2)topological phase of monolayer TalrTe_(4),the zero Chern number can be understood as 1-1=O from the double band inversion from spinup and spin-down channels.After applying a magnetic field perpendicular to the plane,the Zeeman split changes the band order for one branch of the band inversion from spin-up and spin-down channels,along with a sign charge of the Berry phase.Then,the net Chern number of 1-1=0 is tuned to 1+1=2 or-1-1=-2 depending on the orientation of the magnetic field.The quantized signal not only provides another effective method for the verification of topological state in monolayer TalrTe_(4)but also offers a strategy for the utilization of the new quantum topological states based on switchable quantized responses.
