Laser-driven inverse electronic bridge process: An optical tool for determining low-energy separation of nearby nuclear states

Abstract

An optical method to determine the low-energy separation (1\ifmmode\pm\else\textpm\fi{}4 eV) of nearby nuclear states of $^{229}\mathrm{Th}$ is presented. It is shown that the Coulomb field of a deexciting electron of the $^{229}\mathrm{Th}$ atom can cause transition between the near-lying nuclear states if the atom emits a photon with an energy equal to the difference between the energies of the electron and nuclear transitions. It is also predicted that the process can be enhanced through induced emission by applying a laser of resonant photon energy. The transition probabilities per unit time of the spontaneous and the laser induced processes are given.