Fabrication and Characterization of Modulation-Doped ZnSe/(Zn,Cd)Se (110) Quantum Wells: A New System for Spin Coherence Studies

TL;DR

This paper reports on the growth and characterization of modulation-doped ZnSe/(Zn,Cd)Se quantum wells on (110) GaAs substrates, revealing unique growth conditions and comparable spin relaxation times to (100) samples, which is unexpected for spin coherence studies.

Contribution

It introduces a new system of (110)-oriented quantum wells with tailored growth conditions and demonstrates their spin relaxation properties, expanding understanding of spin dynamics in these structures.

Findings

Successful growth of (110) quantum wells with distinct conditions

Confirmation of 2D electron gas formation via magnetotransport

Similar spin relaxation times in (110) and (100) samples

Abstract

We describe the growth of modulation-doped ZnSe/(Zn,Cd)Se quantum wells on (110) GaAs substrates. Unlike the well-known protocol for the epitaxy of ZnSe-based quantum structures on (001) GaAs, we find that the fabrication of quantum well structures on (110) GaAs requires significantly different growth conditions and sample architecture. We use magnetotransport measurements to confirm the formation of a two-dimensional electron gas in these samples, and then measure transverse electron spin relaxation times using time-resolved Faraday rotation. In contrast to expectations based upon known spin relaxation mechanisms, we find surprisingly little difference between the spin lifetimes in these (110)-oriented samples in comparison with (100)-oriented control samples.