Spin-relaxation mechanisms in InAs quantum well heterostructures

Abstract

Spin–orbit interaction and spin-relaxation mechanisms of a shallow InAs quantum well heterostructure are investigated by magnetoconductance measurements as a function of an applied top-gate voltage. The data are fit using a Iordanskii–Lyanda-Geller–Pikus model and two distinct transport regimes are identified. The spin–orbit interaction splitting energy is extracted from the fits to the data, which also displays two distinct regimes. The different regimes exhibit different spin-scattering mechanisms, the identification of which is of relevance for device platforms of reduced dimensionality which utilize the spin–orbit interaction.

Improvement of Carrier Mobility in Quantum Wells by the Surface Smoothing of Strain-Relaxed Buffer Layers

“…The InAs QW structures were examined for the application as transistors because of the large electron mobility realized by the small effective mass . Recently, the strong spin-orbit coupling of InAs has attracted attention for utilizing two-dimensional electron gases (2DEGs) for spintronics applications. − In growing the QW structures, the electron accumulation at the surface of bulk InAs makes it necessary to employ other materials as nonconductive substrates, at least, for electrical devices. − Here, the layers typically relax during the heteroepitaxy mentioned above as a consequence of the relatively large lattice mismatch . Despite the relaxation, however, the mobility of the 2DEGs in the QWs is large.…”