[18p-D61-1~21] 10.4 Spintronics in semiconductor, topological material, superconductor, and multiferroics

4:00 PM - 4:15 PM JST(7:00 AM - 7:15 AM UTC)Presentation by Applicant for JSAP Young Scientists Presentation AwardEnglish Presentation

[18p-D61-12] Enhancement of Rashba Spin-Orbit Interaction Based on Quaternary InGaAsP/InGaAs Single Quantum Well by Bayesian Optimization

〇Keito Kikuchi¹, Kohei Yoshizumi¹, Sota Yamamoto¹, Jun Ishihara¹, Makoto Kohda^1,2,3,4 (1.Grad. Sch. of Eng., Tohoku Univ., 2.CSIS, Tohoku Univ., 3.DEFS, Tohoku Univ., 4.QUARC, QST)

Keywords:

Spin-orbit interaction,Two-dimensional electron gas,Bayesian optimization

In two-dimensional electron gases, the Rashba spin-orbit interaction (SOI) is influenced by internal electric fields and controlled by an external gate bias. Enhancing Rashba SOI is crucial for semiconductor technology and spintronics but is challenging due to many variables. We used Bayesian optimization to find quantum structures that maximize Rashba SOI. Our base structure is an i-HEMT InGaAsP/InGaAs QW with parameters including QW width, composition ratios, Si doping concentration, and top gate voltage. Using nextnano for simulation, we calculated the wave function, band structure, and Rashba SOI, optimizing with Bayesian methods. The optimized structure, featuring an InP/InAs interface, significantly increased Rashba SOI due to a large valence-band offset (ΔE_Γ8), doubling the Rashba SOI parameter compared to previous structures. This demonstrates the effectiveness of our approach in enhancing internal electric fields at the interface.