Enhanced quantum sensing with room-temperature solid-state masers

TL;DR

This paper demonstrates that room-temperature solid-state maser technology can significantly improve quantum sensing by reducing linewidth and enhancing readout, leading to higher sensitivity in detecting physical quantities.

Contribution

The study introduces a room-temperature solid-state maser that narrows linewidths and improves readout, advancing quantum sensing capabilities beyond previous limitations.

Findings

Achieved a 4-fold reduction in linewidth of molecular spin ensembles

Demonstrated a 30 dB SNR in single-shot magnetometry

Showed maser action narrows linewidth below cryogenic single-spin levels

Abstract

Quantum sensing with solid-state systems finds broad applications in diverse areas ranging from material and biomedical sciences to fundamental physics. Several solid-state spin sensors have been developed, facilitating the ultra-sensitive detection of physical quantities such as magnetic and electric fields and temperature. Exploiting collective behaviour of non-interacting spins holds the promise of pushing the detection limit to even lower levels, while to date, those levels are scarcely reached due to the broadened linewidth and inefficient readout of solid-state spin ensembles. Here, we experimentally demonstrate that such drawbacks can be overcome by newly reborn maser technology at room temperature in the solid state. Owing to maser action, we observe a 4-fold reduction in the inhomogeneously broadened linewidth of a molecular spin ensemble, which is narrower than the same measured from single spins at cryogenic temperatures. The maser-based readout applied to magnetometry showcases a signal-to-noise ratio (SNR) of 30 dB for single shots. This technique would be a significant addition to the toolbox for boosting the sensitivity of solid-state ensemble spin sensors.