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Tuesday, 6 August 2013

Johannes Floß: DM: Quantum resonance, Anderson localisation and selective rotational excitation in periodically kicked molecules

guest speaker: Johannes Floß, Department of Chemical Physics, Weizmann Institute of Science, Israel

The periodically kicked rotor has attracted much attention in the recent decades. In the classical regime the kicked rotor can exhibit truly chaotic motion, whereas in the quantum mechanical analogue, this chaotic motion is suppressed by Anderson-like localisation of the wave function in momentum space [1]. On the other hand, when the kicking period is equal to the rotational revival time, the kicked quantum rotor exhibits quantum resonance, an effect which leads to a linear increase of the angular momentum with the number of kicks [2]. Until today these phenomena were observed experimentally mainly in an atom optics analogue of a kicked rotor [3].

In this talk, I will provide an introduction to the two phenomena of quantum resonance and Anderson localisation in periodically kicked rotors. Then I will show how standard laser techniques used for molecular alignment provide a new way for observing these phenomena in a real rotor system, a diatomic molecule [4, 5]. I will also show that these phenomena provide a new toolbox for selective laser manipulations in molecular mixtures.

[1] S. Fishman, D. R. Grempel, and R. E. Prange, Phys. Rev. Lett. 49, 509 (1982).
[2] F. M. Izrailev and D. L. Shepelyanskii, Theor. Math. Phys. 43, 553 (1980).
[3] F. L. Moore, J. C. Robinson, C. Bharucha, B. Sundaraman, and M. G. Raizen, Phys. Rev.
Lett. 75, 4598 (1995).
[4] J. Floß and Ilya Sh. Averbukh, Phys. Rev. A 86, 021401 (R) (2012).
[5] J. Floß, S. Fishman, and Ilya Sh. Averbukh, arXiv 1305.5995 (2013).