Hexagonal Boron Nitride Quantum Simulator: Prelude to Spin and Photonic Qubits

Area of Science:

• Quantum Information Science and Technology
• Solid-State Physics
• Materials Science

Background:

• Solid-state quantum defects with spin-optical properties are key for room-temperature quantum operations.
• The boron vacancy (V^-) defect in hexagonal boron nitride (h-BN) offers coherent quantum interfaces for spin and photonic qubits due to h-BN's large band gap shielding.
• Understanding the defect's Hamiltonian is crucial for its use as a quantum simulator.

Purpose of the Study:

• To design and characterize the Hamiltonian of the V^- defect in h-BN.
• To investigate electron-phonon interactions and Jahn-Teller distortions affecting phonon-assisted single photon emission.
• To demonstrate the Hamiltonian's utility in quantum information processing and guide the selection of 2D materials for qubits.

Main Methods:

• Studied key coupling tensors: zero-field splitting, Zeeman effect, and hyperfine splitting.
• Characterized the Hamiltonian by electron-phonon interaction with Jahn-Teller distortions.
• Utilized a data-mining perspective for selecting host 2D materials based on Hamiltonian engineering.

Main Results:

• Developed a Hamiltonian for the V^- defect, describing spin triplet states as a computational subspace.
• Investigated phonon-assisted single photon emission mechanisms.
• Identified h-BN as a promising room-temperature qubit candidate among four selected 2D materials.

Conclusions:

• The V^- defect Hamiltonian provides a framework for understanding quantum properties and their application in spin- and photonic-quantum information processing.
• Hamiltonian engineering is a viable approach for selecting suitable 2D materials for room-temperature qubits.
• The study advances the development of solid-state qubits for quantum technologies.