Three-dimensional bulk band dispersion in polar BiTeI with giant Rashba-type spin splitting

Abstract

In layered polar semiconductor BiTeI, giant Rashba-type spin-split band dispersions show up due to the crystal structure asymmetry and the strong spin-orbit interaction. Here we investigate the 3-dimensional (3D) bulk band structures of BiTeI using the bulk-sensitive hν-dependent soft x-ray angle resolved photoemission spectroscopy (SX-ARPES). The obtained band structure is shown to be well reproducible by the first-principles calculations, with huge spin splittings of ∼300 meV at the conduction-band-minimum and valence-band-maximum located in the k z = π/c plane.It provides the first direct experimental evidence of the 3D Rashba-type spin splitting in a bulk compound.

Quantum oscillations and optical conductivity in Rashba spin-splitting BiTeI

“…1 reported an even larger Rashba splitting, α R = 3.8 eVÅ, in the bulk electronic bands of BiTeI. Optical spectroscopy of this compound found indeed an electronic excitation spectrum consistent with the splitting of the bulk conduction and valence bands 5 and further photoemission study suggested the 3D nature of these bands 6 . More recent ARPES reports however, indicated the reconstruction of the band structure at the Te (or I) terminated surface and the existence of surface electronic branches, possibly with even larger Rashba spinsplitting 7,8 .…”

Optical, electronic, and elastic properties of some A5B6C7ferroelectrics (A=Sb, Bi; B=S, Se; C=I, Br, Cl): First principle calculation

“…Such a low value is a good indicator for an adequate convergence of the calculations. [30][31][32][33][34][35][36][37][38][39]. The atomic positions belonging to these compounds are given in Table 1.…”

Crystal and electronic structure of BiTeI, AuTeI, and PdTeI compounds: A dispersion-corrected density-functional study

“…A1, which is in line with the former studies. 44,45,49 The difference k CBM − k VBM is largest [0.181Å −1 for PBE w/o SOC] when SOC and dispersion correction are both ignored, which is reduced to 0.044Å −1 (0.077Å −1 ) via inclusion of SOC (dispersion correction). Taking SOC and dispersion correction into account together yields the smallest difference k CBM − k VBM = 0.010Å −1 (PBE-D2).…”