Searches for violation of fundamental time reversal and space reflection symmetries in solid state experiments

TL;DR

This paper evaluates the potential of solid state experiments to detect violations of time reversal and space reflection symmetries via electric dipole moments, focusing on Gd-based compounds and nuclear effects.

Contribution

It provides theoretical calculations of T,P-violation effects in solid state systems and proposes experimental sensitivity to nuclear forces and Schiff moments.

Findings

Main T,P-odd effects arise from oxygen electron penetration into Gd core

Effects are linked to crystal lattice deformation

Solid state experiments could surpass atomic/molecular sensitivity

Abstract

The electric dipole moment (EDM) of a particle violates both time reversal (T) and space reflection (P) symmetries. There have been recent suggestions for searches of the electron EDM using solid state experiments [1,2]. These experiments could improve the sensitivity compared to present atomic and molecular experiments by several orders of magnitude. In the present paper we calculate the expected effect. We also suggest that this kind of experiment is sensitive to T,P-violation in nuclear forces and calculate effects caused by the nuclear Schiff moment. The compounds under consideration contain magnetic Gd$^{3+}$ ions and oxygen O$^{2-}$ ions. We demonstrate that the main mechanism for the T,P-odd effects is related to the penetration of the Oxygen 2p-electrons to the Gd core. All the effects are related to the deformation of the crystal lattice.