ELFT HÍRADÓ

[tcsaba <tcsaba AT eik.bme.hu>]

                 M E G H Í V Ó - I N V I T A T I O N

    Seminar Series of the Department of Theoretical Physics at the
           Budapest University of Technology and Economics


                          Mikhail Lemeshko
            (Institute of Science and Technology Austria)

            The angulon quasiparticle: from molecules in
                  superfluids to ultrafast magnetism


Recently we have predicted a new quasiparticle - the angulon - which is 
formed when a quantum impurity (such as an electron, atom, or molecule) 
exchanges its orbital angular momentum with a many-particle environment 
(such as lattice phonons or a Fermi sea) [1,2].

Soon thereafter we obtained strong evidence that angulons are formed in 
experiments on molecules trapped inside superfluid helium nanodroplets 
[3]. The angulon theory thereby provided a simple explanation for 
experimental data accumulated during the last two decades. Moreover, 
casting the many-particle problem in terms of angulons amounts to a 
drastic simplification and allows to tackle previously intractable 
problems related to quantum dynamics [4].

In this presentation we will introduce the angulon concept and discuss 
novel physical phenomena [1,5,6] arising from the angular momentum 
exchange in quantum many-particle systems. We will describe the 
applications of angulons to modern experiments on quantum impurities and 
on non-equilibrium magnetism [7].

[1] R. Schmidt, M. Lemeshko, Phys. Rev. Lett. 114, 203001 (2015)
[2] R. Schmidt, M. Lemeshko, Phys. Rev. X 6, 011012 (2016)
[3] M. Lemeshko, Phys. Rev. Lett., 118, 095301 (2017); Viewpoint: 
Physics 10, 20 (2017)
[4] B. Shepperson, A. A. Sondergaard, L. Christiansen, J. Kaczmarczyk, 
R. E. Zillich, M. Lemeshko, H. Stapelfeldt, Phys. Rev. Lett. 118, 203203 
(2017)
[5] E. Yakaboylu, M. Lemeshko, Phys. Rev. Lett. 118, 085302 (2017)
[6] E. Yakaboylu, A. Deuchert, M. Lemeshko, Phys. Rev. Lett. 119, 235301 
(2017)
[7] J.H. Mentink, M.I. Katsnelson, M. Lemeshko, Phys. Rev. B 99, 064428 
(2019)


Időpont: 2019. április 5. péntek, 10:15
Helyszín: BME Fizikai Intézet, Elméleti Fizika Tanszék,
Budafoki út 8. F-épület, III lépcsőház, szemináriumi szoba