Exploring Molecular Orbital Pseudospins as All-Optical Quantum Sensors

Area of Science:

• Quantum Information Science
• Molecular Spectroscopy
• Condensed Matter Physics

Background:

• Molecular qubits typically utilize electron spin states, requiring spin-optical interfacing for quantum sensing.
• Molecular electronic states can form pseudospins, offering a potential alternative qubit modality.
• All-optical quantum sensing aims to bypass complex spin-optical interfaces.

Purpose of the Study:

• To investigate the feasibility of using molecular orbital pseudospin precessions for all-optical quantum sensing.
• To determine if pseudospin oscillations are detectable in isotropic environments using optical pump-probe spectroscopy.
• To assess the limitations imposed by electronic decoherence on pseudospin-based quantum sensing.

Main Methods:

• Theoretical analysis of molecular orbital pseudospin dynamics under environmental influence.
• Modeling optical pump-probe spectroscopy to detect pseudospin precessions.
• Evaluation of decoherence effects on pseudospin qubit stability.

Main Results:

• Molecular orbital pseudospin oscillations can survive rotational averaging and are detectable in isotropic environments.
• Fast electronic decoherence is a significant limitation, restricting measurements to specific environmental interactions.
• The predictability of molecular electronic states allows for potential molecular engineering solutions.

Conclusions:

• All-optical quantum sensing using molecular orbital pseudospins is theoretically possible but faces challenges from electronic decoherence.
• Further molecular engineering is crucial to mitigate decoherence and enhance the speed and applicability of pseudospin qubits.
• Pseudospin-based qubits may offer advantages over traditional spin qubits if decoherence issues are addressed.