Spin echo from erbium implanted silicon

TL;DR

This study demonstrates the spin echo properties of erbium-implanted silicon, revealing coherence times and interactions relevant for quantum technology applications.

Contribution

It provides the first detailed measurement of spin coherence and relaxation times in erbium-implanted silicon, highlighting the effects of super-hyperfine interactions and spectral diffusion.

Findings

Electron spin coherence time T2 is 7.5 microseconds at 5 K.

Spin-lattice relaxation time T1 is approximately 1 millisecond.

Spectral diffusion limits T2 due to T1-induced flips of neighboring Er3+ spins.

Abstract

Erbium implanted silicon as a quantum technology platform has both telecommunications and integrated circuit processing compatibility. In Si implanted with Er to a concentration of 3x10^17 cm^3 and O to a concentration of 10^20 cm^3, the electron spin coherence time, T2, and the spin-lattice relaxation time, T1, were measured to be 7.5 ls and ~1 ms, respectively, at 5 K. The spin echo decay profile displayed strong modulation, which was consistent with the super-hyperfine interaction between Er3{\th} and a spin bath of 29Si nuclei. The calculated spectral diffusion time was similar to the measured T2, which indicated that T2 was limited by spectral diffusion due to T1-induced flips of neighboring Er3{\th} spins. The origin of the echo is an Er center surrounded by six O atoms with monoclinic C1h site symmetry.