Quantum Sensing with van der Waals Heterostructures based on hexagonal Boron Nitride

Introduction

The project idea is to implement a new quantum probe based on hexagonal boron nitride (hBN) containing spin defects to study the properties of artificially stacked two-dimensional (2D) materials and devices.

Background

The essential building blocks of such van der Waals (vdW) heterostructures are the quantum defects in hBN recently discovered by the PI and his team. These intrinsic lattice defects - negatively charged boron vacancies (VB) - can be optically spin-polarized and coherently manipulated, allowing the read-out of quantum information during the coherence time.

Experimental Approach

Our experimental approach is based on coherent manipulation of the spin state using high-frequency pulse protocols, followed by optical readout to explore the adjacent environment. This includes studying:

1. Local lattice strains
2. Pressure
3. Temperature
4. Magnetic fields

Unique Features of hBN

The unique feature of hBN is its non-disturbing chemical and crystallographic compatibility with other vdW materials. This compatibility gains a new fundamental functionality with the embedded spin centers and allows sensing in heterostructures serving as a boundary itself.

Optical and Electrical Control

Optical readout will be extended by electrical control of spin and charge states, which is an unexplored area and a major step forward in the development of quantum applications of vdW heterostructures.

Focus Areas

We focus on:

i) The enhancement of VB emission and spin resonance contrast by coupling with plasmonic resonators to identify single defects never seen before.
ii) The identification of the sources of spin decoherence of these defects, in particular the interaction with other electronic defects and hyperfine-coupled nuclear bath, and their bypassing.
iii) The exploration of semiconducting and magnetic heterostructures and electronic devices based on them.

Project Goals

The project aims to establish 2D heterostructures as a flexible platform for new quantum applications based on the optical and electrical control of coherent states and mapping fluctuating external fields on the nanoscale.