Design of Robust Raman Pulses for Cold Atom Interferometers Based on the Krotov Algorithm

TL;DR

This paper introduces a numerical method using the Krotov algorithm to design robust Raman pulses that enhance the performance of cold-atom interferometers by maintaining high fidelity despite laser noise and imperfections.

Contribution

It presents a novel application of quantum optimal control to create Raman pulses that are resilient to experimental noise, improving interferometer robustness.

Findings

Optimized pulses maintain high fidelity over laser detuning and intensity fluctuations.

Robust pulses improve fringe contrast in simulated interferometer sequences.

Numerical results show enhanced signal-to-noise ratio with the new pulses.

Abstract

The performance of high-precision cold-atom interferometers, which are important for applications in gravimetry and fundamental physics, is often limited by noise and imperfections in the driving laser system. To address this, we propose and numerically demonstrate a method for designing robust Raman pulses using the Krotov quantum optimal control algorithm. We establish a theoretical model for the atom-laser interaction and detail the implementation of the Krotov method to optimize the temporal shape of the pulse's amplitude and phase. Numerical simulations indicate that, compared to standard pulses, the optimized pulses maintain high atomic manipulation fidelity over an extended range of laser frequency detunings and intensity fluctuations. Furthermore, in simulations of a full interferometer sequence, this robustness translates to a significant enhancement in the final fringe contrast under a systematic detuning. This work demonstrates that quantum optimal control is a promising pathway for suppressing experimental noise and improving the signal-to-noise ratio and precision of next-generation atomic sensors.