Dynamics of Photo-excited Spins in InSb Based Quantum Wells

TL;DR

This study investigates how photo-excited spins relax in InSb quantum wells, revealing the effects of laser fluence, doping, temperature, and barrier materials on spin dynamics through time-resolved Kerr effect measurements.

Contribution

It provides new insights into the influence of doping profiles, laser excitation, and barrier materials on spin relaxation in InSb quantum wells.

Findings

Oscillatory spin dynamics at low temperatures in asymmetric doping samples.

Spin relaxation strongly affected by laser fluence and doping profile.

Barrier materials influence spin relaxation behavior.

Abstract

We report time resolved measurements of spin relaxation in doped and undoped InSb quantum wells using degenerate and two-color magneto-optical Kerr effect techniques. We observed that the photo-excited spin dynamics are strongly influenced by laser excitation fluence and the doping profile of the samples. In the low fluence regime, an oscillatory pattern was observed at low temperatures ($\leq$ 77 K) in the samples with an asymmetric doping profile which might be attributed to the quasi-collision-free spin relaxation regime. Our measurements also suggest the influence of the barrier materials (Al$_{x}$In$_{1-x}$Sb) on the spin relaxation in these material systems.