Measuring and controlling molecule-surface collisions using pico-eV coherent manipulations of molecular rotational orientation.

In this seminar I will present results from two recent research projects, both of which make use of magnetic fields to coherently manipulate the rotational and spin quantum states of a molecule during a molecule-surface collision. In one project, magnetic manipulations performed on a molecular beam of H2 colliding with a salt surface, were used to extract an empirically derived scattering matrix, the elements of which describe changes to the molecular wavefunction (magnitude and phase) during the scattering event[1]. In the second project, coherent manipulation of a D2 molecular beam was used to change the rotational orientation of the molecules before they reach a copper surface, and alter the probability of a rotational de-excitation collision J=2->J=0 [2]. In this case a manipulation scheme which is based on pico-eV energy splitting, controls the outcome of a rotational energy loss process which is 9 orders of magnitude larger. Both projects provide challenging and important benchmarks for theoretical modelling of molecule-surface interactions.Finally, I will briefly describe some future applications of our magnetic manipulation technique both in the field of surface science and in the field of gas phase molecular collisions.

[1] Nat. Comms. 11, 3110 (2020)
[2] Nat. Comms.13, 2287 (2022)