Supersymmetry, entanglement, and dynamics of polar paramagnetic molecules subject to combined electric, magnetic, and optical fields

• Applicants: Professor Dr. Bretislav Friedrich; Privatdozent Dr. Burkhard Schmidt
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2014 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 247815525

Interactions with external electric, magnetic or optical fields provide the chief means to manipulate the rotational and translational motion of neutral gas-phase molecules. Among recent developments are new methods to control the orientation and/or alignment of molecules as well as methods to deflect and focus their translational motion and to achieve molecular trapping. The importance of orientation comes also to light in novel applications such as attaining time-resolved photoelectron angular distributions, diffraction-from-within, separation of photodissociation products, deracemization, high-order harmonic generation and orbital imaging, quantum simulation and quantum computing.Herein we propose to study polar paramagnetic molecules subject to a combination of electric, magnetic, and optical fields. Among the most prominent examples of polar paramagnetic molecules are the ubiquitous doublet Sigma, triplet Sigma, and doublet Pi linear species, such as SrF, SO, and OH. Heteronuclear diatomics or larger polar molecules that contain a rare-earth atom often exhibit much higher orbital and spin electronic angular momenta and, therefore, correspondingly larger magnetic dipole moments. The opposite-parity Zeeman levels of polar paramagnetic molecules intersect at a particular value of the magnetic field at which they can be efficiently coupled by a superimposed weak electric field. Our preliminary results suggest that a superimposed optical field may create near-degeneracies of additional levels that could be coupled by the electrostatic field (or the electric dipole-dipole interaction in a molecular ensemble). Thereby, the triple-field combination could enable for instance fast switching of dipolar orientation and other dynamical effects that are not available in a dual magnetic and electric field combination alone. We plan to study the supersymmetry and entanglement of polar paramagnetic molecules in the triple-combination of electric, magnetic and optical fields. Like in the case of polar and polarizable molecules in combined electrostatic and optical fields, we hope that their supersymmetry will guide us to an analytic form of their eigenproperties. Furthermore, we will map out the achievable entanglement for a variety of geometric arrays of molecules and thereby pave the way for an alternative platform for quantum computing. We also propose to investigate the dynamics of polar paramagnetic molecules for a tailored time-dependence of the optical field and to connect the control strategies to the topology of the underlying molecular energy hypersurface in the combined fields, with special emphasis on the prominent role of the conical intersections of their Stark and Zeeman energy surfaces. We expect that this may lead to novel approaches to designing control fields for efficient and state-specific excitation schemes. These will include the control of quantum gates, a key ingredient of quantum computing with molecules.

• DFG Programme: Research Grants
• International Connection: USA
• Participating Persons: Professor Dr. Carsten Hartmann; Dr. Mikhail Lemeshko