Design of defect spins in piezoelectric aluminum nitride for solid-state hybrid quantum technologies

TL;DR

This paper proposes a strain-engineering approach to design defect spins in ionic piezoelectric materials like aluminum nitride, enabling potential qubits in solid-state quantum technologies through advanced ab-initio calculations.

Contribution

It introduces a novel strain-driven method to design defect spins in ionic crystals, expanding quantum defect engineering beyond covalent semiconductors.

Findings

Negatively charged nitrogen vacancy in AlN has spin-triplet ground states under strain.

Strain can be used to control and optimize defect spin properties in ionic materials.

The approach is applicable to other wide-band gap semiconductors for quantum and spintronic applications.

Abstract

Spin defects in wide-band gap semiconductors are promising systems for the realization of quantum bits, or qubits, in solid-state environments. To date, defect qubits have only been realized in materials with strong covalent bonds. Here, we introduce a strain-driven scheme to rationally design defect spins in functional ionic crystals, which may operate as potential qubits. In particular, using a combination of state-of-the-art ab-initio calculations based on hybrid density functional and many-body perturbation theory, we predicted that the negatively charged nitrogen vacancy center in piezoelectric aluminum nitride exhibits spin-triplet ground states under realistic uni- and bi-axial strain conditions; such states may be harnessed for the realization of qubits. The strain-driven strategy adopted here can be readily extended to a wide range of point defects in other wide-band gap semiconductors, paving the way to controlling the spin properties of defects in ionic systems for potential spintronic technologies.