Quantum-Enhanced Metrology for Molecular Symmetry Violation Using Decoherence-Free Subspaces

Area of Science:

• Atomic, Molecular, and Optical (AMO) Physics
• Quantum Metrology
• Chemical Physics

Background:

• Time-reversal symmetry violation is a key area in fundamental physics.
• Measuring subtle effects in molecules is challenging due to quantum decoherence and noise.
• Existing methods often require external fields and are sensitive to environmental disturbances.

Purpose of the Study:

• To develop a novel protocol for measuring time-reversal symmetry violation in molecules.
• To overcome the standard quantum limit in precision measurements.
• To enhance robustness against classical noise using decoherence-free subspaces.

Main Methods:

• Utilizing entangled states within decoherence-free subspaces.
• Designing entangled states with zero average lab-frame projection of spins and dipoles.
• Implementing the protocol without requiring an external electric field.

Main Results:

• The proposed method overcomes the standard quantum limit for measuring time-reversal symmetry violation.
• The protocol demonstrates reduced sensitivity to classical noise through decoherence-free subspaces.
• Entangled states exhibit no first-order sensitivity to static electromagnetic fields.

Conclusions:

• The developed protocol offers a powerful new tool for probing fundamental symmetries in molecules.
• This method is applicable to trapped neutral or ionic species.
• The protocol's feasibility is supported by experimentally demonstrated techniques.