Exploring hyperfine coupling in molecular qubits.

Area of Science:

• Quantum chemistry
• Materials science
• Computational physics

Background:

• Molecular qubits are crucial for quantum sensing and computing, but their performance is limited by challenges in optimization.
• Hyperfine coupling significantly influences molecular qubit properties, yet a complete understanding of its mechanisms across various systems is lacking.

Purpose of the Study:

• To benchmark density functional theory (DFT) methodologies for accurately predicting hyperfine coupling constants in molecular qubits containing V^IV and Cu^II.
• To systematically analyze the contributions of dipolar, isotropic, and spin-orbit interactions to hyperfine coupling.
• To investigate the impact of coordination sphere and molecular geometry on these contributions.

Main Methods:

• Utilized DFT calculations to assess various computational methodologies.
• Analyzed the decomposition of hyperfine coupling into different contributions.
• Modeled diverse molecular systems with varying coordination environments and geometries.

Main Results:

• Identified optimal DFT methodologies for predicting hyperfine coupling constants in V^IV and Cu^II-based molecular qubits.
• Demonstrated that molecular design can precisely tune hyperfine coupling, either minimizing overall interaction or enhancing it along specific axes.
• Quantified the influence of coordination sphere and molecular geometry on dipolar, isotropic, and spin-orbit contributions.

Conclusions:

• Provides crucial insights into structure-property relationships governing hyperfine coupling in molecular qubits.
• Offers guidance on selecting appropriate computational methods (density functional, basis sets, relativistic corrections) for accurate hyperfine coupling predictions.
• Highlights the potential of rational molecular design for optimizing molecular qubit performance in quantum technologies.