Electrically Detected Spin Resonance of Two-Dimensional Carriers in Strained Semiconductor Quantum Wells

Characterizing spin-orbit coupling (SOC) in strained semiconductor quantum wells is important for advancing spin qubit technologies. One of the most direct methods for probing SOC is through precise measurement of the carrier g-factor. We have developed a highly sensitive system for electrically detected spin resonance (EDSR), utilizing a dielectric resonator operating at liquid helium temperatures. Devices were fabricated as field-effect transistor arrays or Hall bars to facilitate measurements.

For example, in a 20 nm Si quantum well, we observed EDSR signals with narrow linewidths (~2 Gauss). By calibrating the magnetic field using DPPH, we determined the out-of-plane g-factor to be 2.0058. Employing a field modulation technique, our setup can detect resistance changes as small as one part per 105. We will discuss potential mechanisms underlying the EDSR signal and explore strategies to further enhance detection sensitivity and efficiency.