Indirect quantum sensors: Improving the sensitivity in characterizing very weakly coupled spins

TL;DR

This paper introduces a method to enhance the sensitivity of nanoscale magnetic resonance imaging by utilizing a long-lived ancilla nuclear spin, enabling detection of larger sample volumes beyond the sensor's T1 limit.

Contribution

The paper presents a novel scheme that leverages an ancilla nuclear spin to improve detection sensitivity and volume in quantum sensors for weakly coupled spins.

Findings

Enhanced detection volume using ancilla nuclear spins

Surpassed T1 limited detection constraints

Maintained characteristic detection time-scales

Abstract

We propose a scheme to increase the sensitivity and thus the detection volume of nanoscale single molecule magnetic resonance imaging. The proposal aims to surpass the T1 limited detection of the sensor by taking advantage of a long-lived ancilla nuclear spin to which the sensor is coupled. We show how this nuclear spin takes over the role of the sensor spin, keeping the characteristic time-scales of detection on the same order but with a longer life-time allowing it to detect a larger volume of the sample which is not possible by the sensor alone.