Quenching Spin Decoherence in Diamond through Spin Bath Polarization

TL;DR

This paper demonstrates that fully polarizing the spin bath in diamond can completely eliminate spin decoherence, significantly enhancing the coherence time of nitrogen-vacancy centers, with potential implications for quantum information processing.

Contribution

The study provides experimental evidence that complete spin bath polarization can suppress decoherence, extending the coherence time of NV centers in diamond at low temperatures.

Findings

Spin decoherence can be eliminated by full spin bath polarization.

Coherence time $T_2$ reaches ~250 μs at 2 K with 99.4% polarization.

Decoherence suppression is due to reduced flip-flop fluctuations in the spin bath.

Abstract

We experimentally demonstrate that the decoherence of a spin by a spin bath can be completely eliminated by fully polarizing the spin bath. We use electron paramagnetic resonance at 240 gigahertz and 8 Tesla to study the spin coherence time $T_2$ of nitrogen-vacancy centers and nitrogen impurities in diamond from room temperature down to 1.3 K. A sharp increase of $T_2$ is observed below the Zeeman energy (11.5 K). The data are well described by a suppression of the flip-flop induced spin bath fluctuations due to thermal spin polarization. $T_2$ saturates at $\sim 250 \mu s$ below 2 K, where the spin bath polarization is 99.4 %.