Roman Krems

Associate Professor

Office: D330
Office Phone: 604-827-3151

Office Hours: any time

FAX: (604) 822-2847
Email: rkrems@chem.ubc.ca

Curriculum Vitae: Undergraduate degree, 1999, Moscow State University, Russia; Ph.D., 2002, Goteborg University, Sweden; Predoctoral Fellow, 2001-02, Harvard-Smithsonian Center for Astrophysics; Postdoctoral Fellow, 2003 - 05, Harvard-MIT Center for Ultracold Atoms, Department of Physics, Harvard University

Theoretical: ultracold matter, quantum dynamics of molecules and molecular interactions, scattering theory, molecular spectroscopy, dynamics of molecules in external elecromagnetic fields

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Research/Teaching Interests

Message for students:

If you want to learn fundamental basics of chemistry and physics, do research in a new and rapidly developing interdisciplinary field, enjoy the privilege of collaborating with many internationally renowned scientists and share the excitement of understanding how the nature works, come talk to me. And remember, if you work hard, the sky's the limit..

The goal of our research is to understand the nature of chemical reactions and find mechanisms to control chemical reactions with external radiation and electromagnetic fields.

Controlling chemical reactions with electromagnetic fields has long been a sought-after goal of researchers. External field control of chemical reactions will not only allow chemists to selectively produce desired species, but also reveal mechanisms of chemical reactions, yield information on interactions determining chemical reactions and elucidate the role of non-adiabatic and relativistic effects in chemical dynamics. Possible applications of controlled chemistry range from quantum computation with molecules, to fundamental tests of reaction rate theories, to studies of fine details of molecular structure or intermolecular interaction potentials. External fields may influence molecular collisions when the translational energy of the molecules is smaller than the perturbation due to interactions with external fields. Moderate magnetic and electric fields available in the laboratory shift molecular energy levels by up to a few Kelvin so external field control of molecular dynamics is only possible at temperatures near or less than one Kelvin. Recent ground-breaking experiments with ultracold matter have led to the creation of molecules near absolute zero and the conditions are now ripe for the realization of controlled chemistry.

Chemical reactions have been shown to occur rapidly at temperatures near zero Kelvin and further studies, both experimental and theoretical, will demonstrate the uniqueness of ultracold chemistry. It may be expected that selection rules are more pronounced and branching ratios of chemical reactions enhanced at ultralow temperatures. The study of ultracold chemistry will take us into a strange new world. Even the smallest activation energy will surely exceed the available thermal energy. However, the large de Broglie wavelength pertaining to the ultracold regime entirely changes the nature of reaction dynamics. At such low temperatures, even the collisions of large molecules exhibit significant quantum effects. Energy barriers on the potential energy surface play a different role because, in the hyperquantum regime, tunneling becomes the dominant reaction pathway. Since tunneling and resonances are characteristic of this regime, they can serve as ultra-sensitive probes of particular features of the potential energy surface.

Ultracold chemistry group (spring of 2008)