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

TL;DR

This paper introduces a quantum metrology protocol utilizing decoherence-free subspaces to detect molecular time-reversal symmetry violation, surpassing classical limits without external fields, applicable to trapped neutral or ionic molecules.

Contribution

It presents a novel quantum measurement scheme that avoids external electric fields and reduces noise sensitivity, enabling more precise detection of symmetry violations in molecules.

Findings

Protocol surpasses standard quantum limit

No need for external electric fields

Compatible with existing trapped ion/molecule methods

Abstract

We propose a method to measure time-reversal symmetry violation in molecules that overcomes the standard quantum limit while leveraging decoherence-free subspaces to mitigate sensitivity to classical noise. The protocol does not require an external electric field, and the entangled states have no first-order sensitivity to static electromagnetic fields as they involve superpositions with zero average lab-frame projection of spins and dipoles. This protocol can be applied with trapped neutral or ionic species, and can be implemented using methods which have been demonstrated experimentally.