Intensity of Hyperfine Structure Components in Parallel and Crossed Electric and Magnetic Fields

Gennadij I. Khvostenko, O. Y. Karasik

А. Ч. Измайлов

Gernot Gwehenberger, Maurizio E. Musso, Christian Neureiter +1 more

Hong Ran, J. Aldegunde, Jeremy M. Hutson

We investigate the microwave spectra of ultracold alkali metal dimers in magnetic, electric and combined fields taking into account the hyperfine structure due to nuclear spins. We consider the molecules 41 K 87 Rb and 7 Li 133 Cs, which are the targets of current experiments, and demonstrate two extremes of large and small nuclear quadrupole couplings. We calculate the frequencies and intensities of transitions that may be used to transfer ultracold molecules between hyperfine states in a magnetic field, employing different polarizations of microwave radiation. In an electric field, the hyperfine levels display narrow avoided crossings at specific fields that we explain in terms of molecular alignment. The hyperfine splittings that arise in electric fields may hinder individual addressing in schemes that use ultracold molecules in quantum computation, but the structure of the spectra is suppressed in combined fields.

V.V. Batyghin, I. N. Toptyghin

Kenji Maeda, Michael L Wall, Lincoln D. Carr

We investigate single-particle energy spectra of the hydroxyl free radical (OH) in the lowest electronic and rovibrational level under combined static electric and magnetic fields, as an example of heteronuclear polar diatomic molecules. In addition to the fine-structure interactions, the hyperfine interactions and centrifugal distortion effects are taken into account to yield the zero-field spectrum of the lowest 2 Π 3 / 2 manifold to an accuracy of less than 2 kHz. We also examine level crossings and repulsions in the hyperfine structure induced by applied electric and magnetic fields. Compared to previous work, we found more than 10% reduction of the magnetic fields at level repulsions in the Zeeman spectrum subjected to a perpendicular electric field. In addition, we find new level repulsions, which we call Stark-induced hyperfine level repulsions, that require both an electric field and hyperfine structure. It is important to take into account hyperfine structure when we investigate physics of OH molecules at micro-Kelvin temperatures and below.