Also called BiTeI, BiTeBr, BiTeCl
In most crystals an electron’s energy does not depend on which way its spin points. In BiTeI it does, strongly: each layer has tellurium on one face and iodine on the other, and that built-in electric field, acting together with heavy bismuth atoms, splits the bands by spin more than in almost any other bulk crystal. This Rashba splitting is the working principle behind proposed spin transistors. The same polarity makes current in BiTeBr flow differently in opposite directions when a magnetic field is applied, and BiTeCl was reported to host a topological surface state even though it lacks inversion symmetry.
They are coordination polyhedra. Only complete ones are drawn.
Three layers of BiTeI. Each layer sits directly over the one below, iodine facing tellurium across each gap, so every layer points the same way and the whole crystal is polar: c = 6.85 Å. That polarity is behind its giant Rashba splitting. Cell from Shevelkov and colleagues, Journal of Solid State Chemistry 114, 379 (1995).
Readiness runs lab → prototype → pilot → deployed.
Short notes for specialists. Choose a lens in the header and yours comes first.
The splitting comes from strong spin–orbit coupling on bismuth combined with the polar crystal field. Because the bulk Rashba bands sit near the A point at the gap edge, the physics shows up in bulk spectroscopy, not only at surfaces. The gaps are small enough that the exchange–correlation functional and the treatment of spin–orbit coupling decide whether a calculation finds a normal or a topological phase, and pressure or strain tunes the band inversion.
ARPES on cleaved crystals sees both the bulk Rashba bands and surface states that depend on the termination, so identify which face you cleaved first. Crystals cleave easily and single BiTeI layers have been exfoliated. Nonreciprocal transport and second-harmonic generation probe the polar symmetry directly.
The Rashba splitting is large, but these are narrow-gap, bulk-grown crystals with no scalable thin-film process beyond early epitaxy. They are reference materials for spin–orbit devices rather than candidates for production.
The newest items tagged BiTeX, from the news feed updated 5 Oct 2026.
Bulk-Rashba spin splitting is forbidden in tetradymite topological insulators like Bi2Se3 or Bi2Te3, since their quintuple-layer stacking preserves inversion symmetry. We show that BiSbTeSe2 escapes this restriction: in the Se-Bi-Se-Sb-Te sequence, the structure loses its inversion center, reducing the point group…
Twisted van der Waals bilayers provide a versatile platform for moiré electronic states, yet a transferable symmetry-based principle for time-reversal-invariant Z2 moiré bands has remained largely missing. Here we show that triangular-lattice bilayers with symmetry-related stacking minima provide a geometric route to…
Two-dimensional Janus structures have garnered rapidly growing attention across multidisciplinary fields. However, despite extensive theoretical and experimental efforts, a principle for designing intrinsic Janus materials remains elusive. Here, we propose a first-principles alloy theory based on cluster expansion…
The BiTeX family of polar van der Waals (vdW) semiconductors offers a unique platform for exploring the interplay between polar crystalline structure and nonlinear optical phenomena. Here, we utilize second harmonic generation (SHG) polarimetry to demonstrate giant anisotropic optical nonlinearities in BiTeBr and BiTeI…
All 4 items tagged BiTeX in the news feed · RSS feed for BiTeX