Shubnikov-de Haas Oscillation and Potentiometric Methods for Spin–Orbit Interaction Parameter Measurement in an InAs Quantum Well

Abstract

Rashba spin-orbit interaction (SOI) in double-sided-doped InAs quantum well (QW) structures has been investigated by means of Shubnikov-de Haas oscillation and potentiometric measurements. Different doping density in two separate carrier supply layers induces the asymmetric potential gradient of the InAs QW and larger charge concentration on the side of a more heavily doped carrier supply layer. The Rashba SOI parameter (α) drastically increases from ~ 3.5×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-12</sup> to ~ 6.9×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-12</sup> eV-m as a gate electric field (Vg) decreases from 5 to -10 V. On the other hand, different distances between a ferromagnet and the InAs QW effectuate one order of magnitude difference in junction resistance area (RA). This experimental result distinctly reveals the junction RA between a ferromagnet and a semiconductor QW is a crucial factor to obtain a hysteresis loop-like potentiometric signal.