We present a detailed analysis of Feshbach resonances in ultracold collisions of Li and Cs atoms in the presence of superimposed electric and magnetic fields. We show that electric fields induce resonances through couplings between the
s- and
p-wave scattering channels and modify the scattering length to a great extent. Electric-field-induced resonances lead to the anisotropy of ultracold scattering and provide the diagnostics for magnetic
p-wave resonances in ultracold gases. We show that the electric field couplings may shift the positions of
s-wave magnetic resonances, thereby making the electric field control of ultracold atoms possible even far away from
p-wave resonances. Finally, we demonstrate that electric fields may rotate and spin up the collision complex of ultracold atoms at substantial rates.
We present a detailed analysis of Feshbach resonances in ultracold collisions of Li and Cs atoms in the presence of superimposed electric and magnetic fields. We show that electric fields induce resonances through couplings between the
s- and
p-wave scattering channels and modify the scattering length to a great extent. Electric-field-induced resonances lead to the anisotropy of ultracold scattering and provide the diagnostics for magnetic
p-wave resonances in ultracold gases. We show that the electric field couplings may shift the positions of
s-wave magnetic resonances, thereby making the electric field control of ultracold atoms possible even far away from
p-wave resonances. Finally, we demonstrate that electric fields may rotate and spin up the collision complex of ultracold atoms at substantial rates.
The tunability of the helium-helium interaction through an external electric field is investigated. For a static external field, electric-field-induced resonances and associated electric-field-induced bound states are calculated for the $^{4}\mathrm{He}\text{\ensuremath{-}}^{4}\mathrm{He},^{3}\mathrm{He}\text{\ensuremath{-}}^{4}\mathrm{He}$, and $^{3}\mathrm{He}\text{\ensuremath{-}}^{3}\mathrm{He}$ systems. Qualitative agreement is found with the literature for the $^{3}\mathrm{He}\text{\ensuremath{-}}^{4}\mathrm{He}$ and $^{3}\mathrm{He}\text{\ensuremath{-}}^{3}\mathrm{He}$ systems [E. Nielsen, D. V. Fedorov, and A. S. Jensen, Phys. Rev. Lett. 82, 2844 (1999)]. The implications of the predicted electric-field-induced resonances for $^{4}\mathrm{He}\text{\ensuremath{-}}^{4}\mathrm{He}$ on the wave packet dynamics, initiated by intense laser pulses, are investigated. Our results are expected to guide next generation experiments.