Crystal growth and electronic properties of a 3D Rashba material, BiTeI, with adjusted carrier concentrations

TL;DR

This study successfully grew large BiTeI single crystals with tunable electronic states, revealing their 3D Rashba electronic structures through experimental growth techniques and first-principles calculations, advancing spin-related material research.

Contribution

It introduces methods to grow sizable BiTeI crystals with controlled carrier concentrations and characterizes their 3D Rashba electronic states.

Findings

Crystals with metallic to insulating states were successfully grown.

The 3D Rashba Fermi surface topology was characterized.

Different growth techniques yielded varied electronic properties.

Abstract

3D Rashba materials can be a leading player in spin-related novel phenomena, ranging from the metallic extreme (unconventional superconductivity) to the transport intermediate (spin Hall effects) to the novel insulating variant (3D topological insulating states). As the essential backbone for both fundamental and applied research of such a 3D Rashba material, this study established the growth of sizeable single crystals of a candidate compound BiTeI with adjusted carrier concentrations. Three techniques (standard vertical Bridgman, modified horizontal Bridgman, and vapour transport) were employed, and BiTeI crystals (> 1 * 1 * 0.2 mm3) with fundamentally different electronic states from metallic to insulating were successfully grown by the chosen techniques. The 3D Rashba electronic states, including the Fermi surface topology, for the corresponding carrier concentrations of the obtained BiTeI crystals were revealed by relativistic first-principles calculations.