Strain Quantum Sensing with Spin Defects in Hexagonal Boron Nitride

Abstract

Hexagonal boron nitride is not only a promising functional material for the development of two-dimensional optoelectronic devices but also a good candidate for quantum sensing thanks to the presence of quantum emitters in the form of atom-like defects. Their exploitation in quantum technologies necessitates understanding their coherence properties as well as their sensitivity to external stimuli. In this work, we probe the strain configuration of boron vacancy centers (VB − ) created by ion implantation in h-BN flakes thanks to wide-field spatially resolved optically detected magnetic resonance and submicro Raman spectroscopy. Our experiments demonstrate the ability of VB − for quantum sensing of strain and, given the omnipresence of h-BN in 2D-based devices, open the door for in situ imaging of strain under working conditions.

Quantum Emitters in Hexagonal Boron Nitride

“…This multitude of creation methods, a consequence of the simple monovacancy structure of the defect, allows for precise defect engineering and placement, for instance to couple V B – defects to photonic structures ,− and for sensing applications. Proof-of-principle demonstrations of quantum imaging have been reported, − using dense layers of V B – defects created by ion irradiation in thin hBN flakes, with the flake placed on top of a sample of interest. Example results are given in Figure e,f which show magnetic field and temperature images obtained by spatially mapping the ODMR spectrum of the hBN flake stacked onto a van der Waals magnetic flake.…”

Detection of Paramagnetic Spins with an Ultrathin van der Waals Quantum Sensor

“…to a trilayer flake with the defect in the middle layer) and with no surface-induced background magnetic noise, which could lead to future opportunities in ultrasensitive quantum sensing. Recently, hexagonal boron nitride (hBN) has emerged as a promising material platform to realize such ultrathin quantum sensors. − hBN is an exfoliable, air-stable vdW material and is host to a robust, optically addressable spin defect, the negatively charged boron vacancy (V B – ). , The V B – defect can be introduced in the hBN lattice through a variety of irradiation methods, , and several demonstrations of quantum sensing have subsequently been reported, including the detection and imaging under ambient conditions of static magnetic fields, temperature, and strain ,− and the imaging of magnetic noise from a ferromagnetic material at cryogenic temperatures …”

“…In this work, we demonstrate the detection of magnetic noise from paramagnetic spins with an hBN quantum sensor under ambient conditions. In contrast with previous quantum sensing demonstrations which employed hBN flakes exfoliated from bulk crystals, ,− here we use hBN nanopowder, an aggregate of nanoscale flakes, which forms a convenient, readily scalable, and cost-effective alternative for sensing in a wider range of environments including in solution. We first characterize the spin properties of the V B – defects created in hBN nanopowder and find the T 1 time is comparable to that in a bulk hBN crystal.…”

Radiation pressure backaction on a hexagonal boron nitride nanomechanical resonator

“…32,33 A recent study on these vacancies has shown control at room temperature of a protected qubit basis, with a coherence time as high as 0.8 µs. 34 These spin defects are also sensitive to strain, 35,36 making hBN a promising material to develop the field of spin-mechanics and spin-optomechanics. 37,38 Indeed, these hybrid systems could enable the communication between photons and qubits within hBN, a new step toward quantum networks and quantum communication, and an alternative system to the leading platform of nitrogen vacancy centers in diamond.…”