# Decoherence of Quantum-Enhanced Timing Accuracy

## TL;DR

This paper investigates how optical loss, dispersion, and nonlinearity affect quantum-enhanced optical pulse timing accuracy, analyzing decoherence impacts on surpassing the quantum limit and the survival of timing enhancements.

## Contribution

It develops a formalism to study decoherence effects on quantum timing enhancement and evaluates the feasibility of maintaining quantum advantages with current technology.

## Key findings

- Optical loss significantly impacts timing precision.
- Quantum enhancement can be achieved despite increased jitter.
- Certain conditions allow quantum timing advantages to survive decoherence.

## Abstract

Quantum enhancement of optical pulse timing accuracy is investigated in the Heisenberg picture. Effects of optical loss, group-velocity dispersion, and Kerr nonlinearity on the position and momentum of an optical pulse are studied via Heisenberg equations of motion. Using the developed formalism, the impact of decoherence by optical loss on the use of adiabatic soliton control for beating the timing standard quantum limit [Tsang, Phys. Rev. Lett. 97, 023902 (2006)] is analyzed theoretically and numerically. The analysis shows that an appreciable enhancement can be achieved using current technology, despite an increase in timing jitter mainly due to the Gordon-Haus effect. The decoherence effect of optical loss on the transmission of quantum-enhanced timing information is also studied, in order to identify situations in which the enhancement is able to survive.