Valley-resolved transport in zigzag graphene nanoribbon junctions

• 作者: Ming Li Zi-Liang Cai Zhi-Bo Feng Zheng-Yin Zhao
• 来源期刊: 理论物理通讯（英文版）
• 年，卷（期）: 2021,（11）
• 所属期刊栏目: CONDENSED MATTER THEORY
• 页码范围: 157-164
• 页数: 8页
• 语种: 英文

摘要

Applying the transfer matrix and Green's function methods,we study the valley-resolved transport properties of zigzag graphene nanoribbon(ZGNR)junctions.The width of the left and right ZGNRs are NL and NR,and NL≥NR.The step/dip positions of the conductance G,the intravalley transmission coefficients(TKK and TK'K'),and the valley polarization efficiency PKK'correspond to the subband edges of the right/left ZGNR that are controlled by NR/NL.The intervalley transmission coefficients(TKK'and TK'K)exhibit peaks at most of the subband edge of the left and right ZGNRs.In the bulk gap of the right ZGNR,TKK'=TK'K=0,and PKK'=±1,the valley polarization is well preserved.As NR increases,the energy region for PKK'=±1 decreases.When NL is fixed and NR decreases,G,TKK,TK'K'and PKK'exhibit more and more dips,and the peaks of TKK'(TK'K)become more and more high,especially when(NL-NR)/2 is odd.These characters are quite useful for manipulating the valley dependent transport properties of carriers in ZGNR junctions by modulating NL or NR,and our results are helpful to the design of valleytronics based on ZGNR junctions.