Vibronic Engineering for Quantum Functional Groups

Area of Science:

• Molecular quantum information science
• Quantum chemistry
• Materials science

Background:

• Functional groups in chemistry provide specific properties to molecules.
• Quantum functional groups (QFGs) are proposed as molecular analogues for quantum state preparation and measurement (SPAM).
• Molecular systems present challenges for quantum information processing due to numerous degrees of freedom leading to dephasing.

Purpose of the Study:

• To explore chemical design principles for optimizing QFG performance.
• To investigate molecular scaffolds that can host QFGs without compromising quantum properties.
• To derive rules for vibronic engineering of molecules for QFG functionality.

Main Methods:

• Design and synthesis of alkaline-earth (I) alkoxides (MOR) as QFGs, specifically the -OM (M = Ca, Sr) motif.
• Attachment of QFGs to various aliphatic and aromatic hydrocarbon scaffolds.
• Analysis of chemical factors (conjugation, conformer formation, electron-withdrawing abilities, symmetry) influencing optical cycling properties.
• Exploration of physical phenomena (Fermi resonances, super radiance) relevant to QFG qubit performance.

Main Results:

• Alkaline-earth alkoxides demonstrate potential for efficient SPAM.
• The -OM (M = Ca, Sr) motif effectively functions as a quantum handle.
• Chemical properties significantly impact the optical cycling behavior of QFGs.
• Initial rules for vibronic engineering toward QFG functionality have been established.

Conclusions:

• QFGs, particularly alkaline-earth alkoxides, offer a promising route for molecular quantum computing.
• Judicious molecular design and vibronic engineering are crucial for overcoming decoherence in molecular qubits.
• Further prospects exist for increasing QFG number densities through advanced molecular and material design.