Topological edge states have crucial applications in the future nano spintronics devices.In this work,circularly polarized light is applied on the zigzag silicene-like nanoribbons resulting in the anisotropic chiral edge modes.An energy-dependent spin filter is designed based on the topologi-cal-insulator(TI)junctions with anisotropic chiral edge states.The reso-nance transmission has been observed in the TI junctions by calculating the local current distributions.And some strong Fabry-Perot resonances are found leading to the sharp transmission peaks.Whereas,the weak and asymmetric resonance corresponds to the broad transmission peaks.In addition,a qualitative relation between the resonant energy separation TR and group velocity vf is derived:TR=πhvfn/L,that indicated TR is proportional to vf and inversely proportional to the length L of the conductor.The different TR between the spin-up and spin-down cases results in the energy-resolved spin filtering effect.Moreover,the intensity of the circularly polarized light can modulate the group velocity vf.Thus,the intensity of circularly polarized light,as well as the conductor-length,play very vital roles in designing the energy-dependent spin filter.Since the transmission gap root in the Fabry-Perot resonances, the thermoelectric (TE) property can be enhanced by adjusting the gap. A schedule to enhance the TE performance in the TI-junction is proposed by modulating the electric field (Ez). The TE dependence on Ez in the nanojunction is investigated, where the appropriate Ez leads to a very high spin thermopower and spin figure of merit. These TI junctions have potential usages in the nano spintronics and thermoelectric devices.

Jia-En Yang;Hang Xie

School of Electronics and loT,Chongqing College of Electronic Engineering,Chongqing 401331,China;College of Physics,Chongqing University,Chongqing 401331,China;Chongqing Key Laboratory for Strongly-Coupled Physics,Chongqing University,Chongqing 401331,China

物理学前沿

[1]Jia-En Yang;Hang Xie-.Energy-resolved spin filtering effect and thermoelectric effect in topological-insulator iunctions with anisotropic chiral edge states)[J].物理学前沿,2022(06):83-91

iunctions,silicene,topologi,hvfn,nanojunction,thermopower

Energy,resolved,filtering,effect,thermoelectric,topological,insulator,anisotropic,chiral,edge,states,Topological,have,crucial,applications,future,spintronics,devices,In,this,work,circularly,polarized,light,applied,zigzag,like,nanoribbons,resulting,modes,energy,dependent,designed,TI,junctions,transmission,has,been,observed,by,calculating,local,current,distributions,And,some,strong,Fabry,Perot,resonances,are,found,leading,sharp,peaks,Whereas,weak,asymmetric,corresponds,broad,addition,qualitative,relation,between,resonant,separation,TR,group,velocity,derived,that,indicated,proportional,inversely,length,conductor,different,down,cases,results,Moreover,intensity,can,modulate,Thus,well,play,very,vital,roles,designing,Since,gap,root,TE,property,enhanced,adjusting,schedule,performance,proposed,modulating,field,Ez,dependence,investigated,where,appropriate,leads,high,figure,merit,These,potential,usages

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