Electromagnetically Induced Transparency with an Ensemble of Donor-Bound Electron Spins in a Semiconductor

TL;DR

This paper demonstrates electromagnetically induced transparency in a semiconductor system using donor-bound electron spins, revealing insights into spin coherence and nuclear polarization effects.

Contribution

It reports the first observation of EIT with donor-bound electrons in low-doped n-GaAs, highlighting the role of hyperfine interactions and nuclear polarization.

Findings

Electron spin dephasing time T* ≈ 2 ns limited by hyperfine coupling.

Weak dynamical nuclear polarization effects observed.

EIT observed in optical transitions of donor-bound electrons.

Abstract

We present measurements of electromagnetically induced transparency with an ensemble of donor- bound electrons in low-doped n-GaAs. We used optical transitions from the Zeeman-split electron spin states to a bound trion state in samples with optical densities of 0.3 and 1.0. The electron spin dephasing time T* \approx 2 ns was limited by hyperfine coupling to fluctuating nuclear spins. We also observe signatures of dynamical nuclear polarization, but find these effects to be much weaker than in experiments that use electron spin resonance and related experiments with quantum dots.