Connection of a Topological Surface State with the Bulk Continuum inSb2Te3(0001)

Abstract

The surface state of a Z(2) topological insulator connects with the conduction and valence band continua of the bulk, thereby bridging the band gap of the volume. We investigate this connection of the surface and bulk electronic structure for Sb(2)Te(3)(0001) by photoemission experiments and calculations. Upon crossing the topmost valence band the topological surface state (TSS) maintains a coherent spectral signature, a two-dimensional character, and a linear dispersion relation. Surface-bulk coupling manifests itself in the spectra through (i) a characteristic kink in the TSS dispersion as it crosses the topmost valence band and (ii) the appearance of hybridization gaps between the TSS and bulk-derived surface resonance states at higher binding energies. The findings provide a natural explanation for the unexpectedly weak surface-bulk mixing indicated by recent transport experiments on Sb(2)Te(3).

Robustness of a Topologically Protected Surface State in a Sb2Te2Se Single Crystal

“…The Rashba splitting in RSS is observed clearly in the plots at 22, 18 and 12 eV. The extracted k F  ~ 0.065 Å −1 and v F of TSS ~2.32 eV Å are consistent with previous work on Sb 2 Te 3 40. The connection between TSS and BVB1 proposed in preceding work is seen also in the plot at 22 and 12 eV.…”

Spatially resolved Landau level spectroscopy of the topological Dirac cone of bulk-typeSb2Te3(0001): Potential fluctuations and quasiparticle lifetime

“…Below LL 0 , only three further peaks are resolved probably due to the overlap of the lower part of the Dirac cone with the bulk valence band [49]. This is in qualitative agreement with a recent ARPES work, which proposes that a change in the TSS wave function occurs at the crossing point between the TSS and the bulk valence band due to hybridization [61]. The character of the TSS wave function is then expected to become more bulk-like leading to less pronounced LLs [62].…”

Scattering properties of the three-dimensional topological insulatorSb2Te3: Coexistence of topologically trivial and nontrivial surface states with opposite spin-momentum helicity

“…1(d) shows a typical STS spectrum obtained on pristine [18,27] which is found at about 170 meV above the Fermi level, i.e. in the empty electronic states, confirming the intrinsic p-doping characterizing the material [19]. This assignment is also corroborated by the position of the zeroth-order Landau level measured at a magnetic field B = 10 T (red line).…”