Probe light-shift elimination in Generalized Hyper-Ramsey quantum clocks

TL;DR

This paper introduces a new interrogation scheme using Generalized Hyper-Ramsey resonances to eliminate light-shift effects in quantum clocks, enabling ultra-precise frequency measurements with high robustness.

Contribution

The authors develop a novel composite pulse sequence method that significantly reduces light-shift errors in quantum clock interrogation, improving stability and accuracy.

Findings

Achieves near-perfect light-shift elimination

Provides robust frequency locking against pulse area variations

Enables quantum clocks to reach below 10^-18 accuracy

Abstract

We present a new interrogation scheme for the next generation of quantum clocks to suppress frequency-shifts induced by laser probing fields themselves based on Generalized Hyper-Ramsey resonances. Sequences of composite laser pulses with specific selection of phases, frequency detunings and durations are combined to generate a very efficient and robust frequency locking signal with almost a perfect elimination of the light-shift from off resonant states and to decouple the unperturbed frequency measurement from the laser's intensity. The frequency lock point generated from synthesized error signals using either $\pi/4$ or $3\pi/4$ laser phase-steps during the intermediate pulse is tightly protected against large laser pulse area variations and errors in potentially applied frequency shift compensations. Quantum clocks based on weakly allowed or completely forbidden optical transitions in atoms, ions, molecules and nuclei will benefit from these hyper-stable laser frequency stabilization schemes to reach relative accuracies below the 10$^{-18}$ level.