Work

Modeling strain and quantum confinement in GaAs/Ga x In1− x P superlattices for spin-polarized electron sources

Year: 2025

Type: article

Abstract: In this study, we systematically design and simulate a series of GaAs-based superlattice configurations aimed at enhancing heavy-hole–light-hole band splitting while simultaneously optimizing band alignment to reduce the conduction band barrier, thereby facilitating efficient electron transport. These combined effects are crucial for achieving high electron spin polarization and high quantum efficiency, the two key performance metrics of next-generation spin-polarized electron sources. We investigated three types of superlattice architectures: (1) compressively strained GaAs wells on GaInP barriers, yielding a maximum band splitting of 140 meV, (2) lattice-matched GaAs/GaInP structures, resulting in the maximum band splitting of 75 meV, and (3) tensile strained GaAs wells on GaInP barriers, with a maximum band splitting of 40 meV. The results demonstrate the tunability of heavy-hole–light-hole band splitting and establish a design framework for high-performance spin-polarized photocathodes based on a combination of strain engineering, quantum confinement, and optimized heterostructure design.

Source: Journal of Applied Physics

DOI: 10.1063/5.0300193

Authors: A. Kachwala, G. Blume, S. Marsillac, J. Grames, M. Grau

Institutions: Thomas Jefferson National Accelerator Facility, Old Dominion University

Language: English

Topic: Semiconductor Quantum Structures and Devices

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,500

Funder: U.S. Department of Energy