Semiconductors with a loop of extrema

E.I Rashba

doi:10.1016/j.elspec.2014.10.002

Abstract

Crystals with a Wurtzite-type structure are used as an example to show that owing to spin–orbit coupling a new type of band structure can arise. For this band structure the extrema are reached at a circle, a loop of extrema, rather than in isolated points of the Brillouin zone. Specific properties of such semiconductors are studied theoretically, in particular, the peculiarities of the cyclotron resonance at low temperatures. In strong magnetic fields, spin–orbit coupling results in absorption at the frequency of electron spin resonance but driven by the electric vector of electromagnetic wave (combined resonance).

Highlights

For this band structure the extrema are reached at a circle, a loop of extrema, rather than in isolated points of the Brillouin zone
PACS numbers: Spin-orbit (SO) coupling can result in a specific band structure such that, in a reasonable approximation, the extremum is reached at a circle, “a loop of extrema”, rather than in isolated points of the Brillouin zone (B.Z.)
The current interpretation of the data on CdS [4] according to which both the bottom of the conduction band and the top of the valence band are reached in the center of the B.Z., and similarity between the optical spectra of CdS and a number of different crystals, suggest that in the crystals of this group the loop of extrema really exists

Summary

Introduction

For this band structure the extrema are reached at a circle, a loop of extrema, rather than in isolated points of the Brillouin zone. Spin-orbit coupling results in absorption at the frequency of electron spin resonance but driven by the electric vector of electromagnetic wave (combined resonance).

Results

Conclusion