New ideas for tests of Lorentz invariance with atomic systems

TL;DR

This paper proposes a new experimental method using atomic systems, including highly charged ions, to test for violations of Lorentz invariance, adaptable to current atomic clock setups.

Contribution

It introduces a broadly applicable dynamic decoupling scheme for Lorentz invariance tests, suitable for systems without optical transitions and demonstrates its feasibility with $^{88}$Sr$^+$ ions.

Findings

Experimental signal measurement with two-ion $^{88}$Sr$^+$ system.

Systematic analysis of highly charged ions' sensitivity to Lorentz violation.

Identification of optimal ions for future Lorentz invariance tests.

Abstract

We describe a broadly applicable experimental proposal to search for the violation of local Lorentz invariance (LLI) with atomic systems. The new scheme uses dynamic decoupling and can be implemented in current atomic clocks experiments, both with single ions and arrays of neutral atoms. Moreover, the scheme can be performed on systems with no optical transitions, and therefore it is also applicable to highly charged ions which exhibit particularly high sensitivity to Lorentz invariance violation. We show the results of an experiment measuring the expected signal of this proposal using a two-ion crystal of $^{88}$Sr$^+$ ions. We also carry out a systematic study of the sensitivity of highly charged ions to LLI to identify the best candidates for the LLI tests.