Theoretical study of ThF$^+$ in the search for T,P-violation effects: Effective state of a Th atom in ThF$^+$ and ThO compounds

TL;DR

This theoretical study investigates the electronic structure of ThF$^+$, highlighting its high effective electric field for eEDM searches and comparing it with ThO, providing key parameters for fundamental symmetry violation experiments.

Contribution

The paper provides detailed theoretical calculations of ThF$^+$ electronic structure, including effective electric fields and T,P-odd interaction parameters, advancing the understanding for eEDM and symmetry violation experiments.

Findings

High effective electric field of 37.3 GV/cm in ThF$^+$ for eEDM detection

Calculated T,P-odd interaction parameters $W_{T,P}$ and $W_M$

Comparison of ThF$^+$ electronic structure with ThO

Abstract

We report the results of theoretical investigation of electronic structure of ThF$^+$ cation which is one of the most interesting systems to search for the electron electric dipole moment (eEDM) [H. Loh, K.C. Cossel, M.C. Grau, K.-K. Ni, E.R. Meyer, J.L. Bohn, J. Ye, E.A. Cornell, Science {\bf 342}, 1220 (2013)] and other effects of violation of time reversal (T) and spacial parity (P) symmetries in fundamental interactions. For the working $^3\Delta_1$ state we have found a quite high value of the effective electric field acting on unpaired electrons (37.3 GV/cm). The field will be required to interpret the experiment planed on ThF$^+$ in terms of eEDM. Within the concept of atoms in compounds [A.V. Titov, Y.V. Lomachuk, and L.V. Skripnikov, Phys. Rev. A {\bf 90}, 052522 (2014)] we have compared the ThF$^+$ electronic structure with that of ThO. Also we have calculated other parameters of T,P-odd interactions: $W_{T,P}$, which is needed for interpretation of the experiment in terms of the dimensionless constant $k_{T,P}$ characterizing the strength of the T,P-odd pseudoscalar$-$scalar electron$-$nucleus neutral current interaction (50 kHz); $W_M$, which is required to search for the Th nuclear magnetic quadrupole moment in $^{229}$ThF$^+$ (0.88 $\frac{10^{33}\mathrm{Hz}}{e {\rm cm}^2}$). A number of properties which can be measured are also calculated: hyperfine structure constant, the molecule-frame dipole moment, and g-factor.