Oscillating nuclear electric dipole moment induced by axion dark matter produces atomic and molecular electric dipole moments and nuclear spin rotation

V V Flambaum,H B Tran Tan

doi:10.1103/physrevd.100.111301

Abstract

According to the Schiff theorem, a static nuclear electric dipole moment (EDM) does not produce atomic and molecular EDMs. However, interaction with the axion dark matter field generates nuclear EDMs ${\mathbf{d}}_{N}={\mathbf{d}}_{N}^{0}\mathrm{cos}(\ensuremath{\omega}t)$ which oscillate with the frequency $\ensuremath{\omega}={m}_{a}{c}^{2}/\ensuremath{\hbar}$. These oscillating nuclear EDMs generate atomic and molecular EDMs proportional to ${\ensuremath{\omega}}^{2}$. The resulting atomic and molecular EDMs do not, however, lead to nuclear spin rotation in constant external electric fields. On the other hand, an oscillating electric field penetrates atoms and molecules and can interact with nuclear EDMs. Moreover, if the nuclear EDM oscillation frequency is in resonance with the external field, nuclear spin rotation happens, with the rotation angle growing linearly with time.

Highlights

It was suggested in Ref. [1] that interactions with axionic dark matter produce oscillating neutrons and oscillating nuclear electric dipole moments (EDMs)
We demonstrate that in the case where the frequency of the external field matches the frequency of the nuclear EDM oscillation, nuclear spin rotation happens with the rotation angle growing linearly with time
We have presented in this paper the possibility of observing axion-induced oscillating nuclear EDMs with oscillating external electric fields

Summary

INTRODUCTION

It was suggested in Ref. [1] that interactions with axionic dark matter produce oscillating neutrons and oscillating nuclear electric dipole moments (EDMs). A constant electric field does not penetrate to the nucleus so there is no interaction with the nuclear EDM, i.e., there will be no nuclear spin rotation for both static and oscillating nuclear EDMs. Observable atomic and molecular EDMs are produced by the nuclear Schiff moment which is suppressed compared to EDMs by an additional second power of the nuclear radius which is very small on the atomic scale [3,4,5,6,7] We demonstrate that in the case where the frequency of the external field matches the frequency of the nuclear EDM oscillation, nuclear spin rotation happens with the rotation angle growing linearly with time

SCREENING THEOREM FOR TIMEDEPENDENT ELECTRIC FIELDS AND EDMS

NUCLEAR EDMs PRODUCED BY THE AXION DARK MATTER FIELD

EVOLUTION OF AN OSCILLATING NUCLEAR EDM IN AN OSCILLATING ELECTRIC FIELD

OSCILLATING ATOMIC ED

OSCILLATING MOLECULAR ED

CONCLUSION