Theory of quasiparticle interference in mirror-symmetric two-dimensional systems and its application to surface states of topological crystalline insulators

Chen Fang, Matthew J. Gilbert, Su-Yang Xu, B. Andrei Bernevig, M. Zahid Hasan
2013 Physical Review B  
We study symmetry protected features in the quasiparticle interference (QPI) pattern of 2D systems with mirror symmetries and time-reversal symmetry, around a single static point impurity. We show that, in the Fourier transformed local density of states (FT-LDOS), ρ(,ω), while the position of high intensity peaks generically depends on the geometric features of the iso-energy contour at energy ω, the absence of certain peaks is guaranteed by the opposite mirror eigenvalues of the two Bloch
more » ... s that are (i) on the mirror symmetric lines in the Brillouin zone (BZ) and (ii) separated by scattering vector . We apply the general result to the QPI on the <001 >-surface of topological crystalline insulator Pb_1-xSn_xTe and predict all vanishing peaks in ρ(,ω). The model-independent analysis is supported by numerical calculations using an effective four-band model derived from symmetry analysis.
doi:10.1103/physrevb.88.125141 fatcat:62zs2mxrzzd53b2h4psxxaojiq