Giant $g$-factors and fully spin-polarized states in metamorphic short-period InAsSb/InSb superlattices

TL;DR

This study demonstrates that metamorphic InAsSb/InSb superlattices can achieve extremely high and tunable electron g-factors, enabling advanced spintronic and quantum computing applications through wavefunction engineering.

Contribution

The paper reports the first observation of a g-factor as high as 104 in InAsSb/InSb superlattices and introduces a method to tune it from 20 to 110 by adjusting the superlattice period.

Findings

Achieved a g-factor of approximately 104, twice that of bulk InSb.

Demonstrated tunability of the g-factor from 20 to 110 by changing superlattice period.

Fully spin-polarized states observed at low magnetic fields.

Abstract

Realizing a large Land\'{e} $g$-factor of electrons in solid-state materials has long been thought of as a rewarding task as it can trigger abundant immediate applications in spintronics and quantum computing. Here, by using metamorphic InAsSb/InSb superlattices (SLs), we demonstrate an unprecedented high value of $g\approx 104$, twice larger than that in bulk InSb, and fully spin-polarized states at low magnetic fields. In addition, we show that the $g$-factor can be tuned on demand from 20 to 110 via varying the SL period. The key ingredients of such a wide tunability are the wavefunction mixing and overlap between the electron and hole states, which have drawn little attention in prior studies. Our work not only establishes metamorphic InAsSb/InSb as a promising and competitive material platform for future quantum devices but also provides a new route toward $g$-factor engineering in semiconductor structures.