Nanoscale magnetometry using a single spin system in diamond

TL;DR

This paper introduces a quantum magnetometry protocol using a single nitrogen-vacancy center in diamond, achieving precision that scales inversely with measurement time, enabling faster and unambiguous magnetic field mapping.

Contribution

It presents a novel phase estimation method for N-V centers that improves magnetic field measurement precision and speed compared to traditional techniques.

Findings

Precision scales close to 1/T, faster than classical methods.

Unambiguous estimation of static magnetic fields.

Potential for rapid, high-resolution magnetic field mapping.

Abstract

We propose a protocol to estimate magnetic fields using a single nitrogen-vacancy (N-V) center in diamond, where the estimate precision scales inversely with time, ~1/T$, rather than the square-root of time. The method is based on converting the task of magnetometry into phase estimation, performing quantum phase estimation on a single N-V nuclear spin using either adaptive or nonadaptive feedback control, and the recently demonstrated capability to perform single-shot readout within the N-V [P. Neumann et. al., Science 329, 542 (2010)]. We present numerical simulations to show that our method provides an estimate whose precision scales close to ~1/T (T is the total estimation time), and moreover will give an unambiguous estimate of the static magnetic field experienced by the N-V. By combining this protocol with recent proposals for scanning magnetometry using an N-V, our protocol will provide a significant decrease in signal acquisition time while providing an unambiguous spatial map of the magnetic field.