Exploring (110)-oriented (In)GaAs/AlGaAs quantum structures for spin lasers

Spin-controlled semiconductor lasers offer potential for applications in optical communications, computing, and sensing. However, achieving electrical spin injection at room temperature remains a challenge. This study explores (110)-oriented III–V quantum wells (QWs) and superlattices (SLs), expected to have long spin relaxation times, as key components for spin lasers. Using molecular beam epitaxy, high-quality (110) (In)GaAs/AlGaAs QWs with nanosecond-scale recombination and spin relaxation times were successfully grown. Additionally, investigations on (110) SLs revealed that electron spin relaxation time depends on both barrier thickness and the number of stacked periods, primarily due to the D’yakonov–Perel mechanism. A comprehensive theoretical analysis revealed that the electron spin relaxation time in these quantum structures can be quantitatively explained by considering all relevant spin relaxation mechanisms. These findings will facilitate the development of spin lasers with (110)-oriented quantum structures.