Lattice-induced non-adiabatic frequency shifts in optical lattice clocks

TL;DR

This paper investigates a specific frequency shift in optical lattice clocks caused by lattice-induced coupling effects, finding it to be negligible for simple geometries but potentially significant for complex systems.

Contribution

It introduces a detailed analysis of lattice-induced non-adiabatic frequency shifts, especially in blue-detuned lattice configurations, and estimates their impact on strontium lattice clocks.

Findings

Fractional frequency shift around 10^{-18} for strontium clocks.

Shift is overshadowed by electric quadrupole effects in simple geometries.

More complex geometries may experience more significant shifts.

Abstract

We consider the frequency shift in optical lattice clocks which arises from the coupling of the electronic motion to the atomic motion within the lattice. For the simplest of 3-D lattice geometries this coupling is shown to only affect clocks based on blue-detuned lattices. We have estimated the size of this shift for the prospective strontium lattice clock operating at the 390 nm blue-detuned magic wavelength. The resulting fractional frequency shift is found to be on the order of $10^{-18}$ and is largely overshadowed by the electric quadrupole shift. For lattice clocks based on more complex geometries or other atomic systems, this shift could potentially be a limiting factor in clock accuracy.