The Limit of Spin Lifetime in Solid-State Electronic Spins

Area of Science:

• Quantum computing
• Materials science
• Computational physics

Background:

• Spin qubits are crucial for quantum technologies.
• Atomic vibrations cause decoherence, limiting qubit performance at finite temperatures.
• Understanding spin relaxation mechanisms is essential for developing robust qubits.

Purpose of the Study:

• To provide a comprehensive first-principles model of spin relaxation, including two-phonon processes.
• To enable accurate prediction of spin lifetimes in realistic molecular qubit systems.
• To investigate the impact of intramolecular vibrations on spin relaxation in vanadium-based molecular qubits.

Main Methods:

• Utilized a combination of machine learning and electronic structure theory.
• Developed a method to simulate spin relaxation including up to two-phonon processes.
• Applied the method to a prototypical vanadium-based molecular qubit.

Main Results:

• Successfully modeled spin relaxation, including two-phonon processes, from first principles.
• Identified Raman processes, driven by low-frequency THz intramolecular vibrations, as the limiting factor for spin lifetime at high temperatures.
• Demonstrated the feasibility of predicting spin lifetimes in realistic systems.

Conclusions:

• The study offers a new understanding of spin relaxation in molecular qubits, challenging conventional models.
• The developed method facilitates the rational design of molecular spin systems with extended lifetimes.
• This work paves the way for more stable and reliable quantum technologies.