Quantum sensor in a single layer van der Waals material

TL;DR

This paper introduces a novel quantum sensor in a single-layer 2D material, hexagonal boron nitride, with enhanced sensitivity and coherence properties, enabling atomic-scale sensing capabilities.

Contribution

The study reports the creation and characterization of a new VB2 defect center in monolayer hBN as a highly sensitive 2D quantum sensor with unique electronic and spin properties.

Findings

Demonstrated the VB2 center's high sensitivity and long coherence times.

Confirmed defect structure via electron microscopy.

Showed potential for atomic-scale sensing in 2D materials.

Abstract

Point defect qubits in semiconductors have demonstrated their outstanding high spatial resolution sensing capabilities of broad multidisciplinary interest. Two-dimensional (2D) semiconductors hosting such sensors have recently opened up new horizons for sensing in the subnanometer scales in 2D heterostructures. However, controlled creation of quantum sensor in a single layer 2D materials with high sensitivity has been elusive so far. Here, we report on a novel 2D quantum sensor, the VB2 centre in hexagonal boron nitride (hBN), with superior sensing capabilities. The centre's inherently low symmetry configuration gives rise to unique electronic and spin properties that implement a qubit in a 2D material with unprecedented sensitivity. The qubit is decoupled from its dense spin environment at low magnetic fields that gives rise to the reduction of the spin resonance linewidth and elongation of the coherence time. The VB2 centre is also equipped with a classical memory that can be utilized in storing population information. Using scanning transmission electron microscopy imaging, we confirm the presence of the point defect structure in free standing monolayer hBN created by electron beam irradiation. Our results provide a new material solution towards atomic-scale sensing in low dimensions.