Non-Markovian renormalization of optomechanical exceptional points

TL;DR

This paper demonstrates that non-Markovian mechanical dissipation significantly shifts exceptional points in optomechanical systems, affecting device performance and spectral signatures, emphasizing the importance of accurate environment modeling.

Contribution

It provides analytical conditions for non-Markovian shifts of exceptional points using pseudomode mapping, highlighting the impact of structured environments on optomechanical systems.

Findings

Memory effects displace the exceptional point from Markovian predictions.

Failing to include non-Markovian effects suppresses the Petermann factor.

Non-Markovianity alters the cavity reflection spectrum, reducing the transparency dip.

Abstract

We investigate how non-Markovian mechanical dissipation affects exceptional points in linearized optomechanical systems with red-sideband drive. For a chosen non-Ohmic mechanical bath, we derive analytical conditions for the memory-renormalized exceptional point by employing a pseudomode mapping, thereby demonstrating that structured environments displace the mode coalescence away from the Markovian prediction. Crucially, we reveal that failing to account for this memory-induced shift suppresses the divergent Petermann factor by orders of magnitude, showing that accurate bath modeling is essential for the successful operation of exceptional-point-based devices whenever reservoir-induced memory is non-negligible. We finally show that non-Markovianity modifies the cavity reflection spectrum, manifesting as a shallower optomechanically-induced-transparency dip, providing therefore an experimentally-accessible signature of structured mechanical environments.