Dresden 2017 – wissenschaftliches Programm

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DS: Fachverband Dünne Schichten

DS 48: Oxide Semiconductors (jointly with HL)

DS 48.4: Vortrag

Freitag, 24. März 2017, 10:30–10:45, POT 51

Excitonic Giant-Dipole Potentials in Cuprous Oxide — •Markus Kurz and Stefan Scheel — AG Quantenoptik makroskopischer Systeme, Institut für Physik, Universität Rostock

Wannier excitons are of great physical interest since they represent the fundamental optical excitation in semiconductors. Recently, the discovery of highly excited Rydberg excitons in Cuprous Oxide (Cu₂O) and their exposure to external fields have shown a plethora of complex physical phenomena [1]. In atomic physics an exotic species of Rydberg atoms in crossed electric and magnetic fields, so-called giant-dipole atoms, have been predicted for two decades [2]. These exotic objects are characterized by an electron-ionic core separation in the range of several micrometers.

In this work, we expand this concept and predict the existence of excitonic giant-dipole states in Cu₂O. Performing a gauge-independent pseudoseparation of the center of mass motion we derive an effective single-particle description of the field-dressed excitonic system obtaining a spatial dependent electron-hole interaction potential. For specific field strengths and field orientations this potential exhibits an outer potential well providing bound excitonic states. Furthermore, we show that the giant-dipole interaction potential gives rise to Abelian and non-Abelian gauge fields acting on the relative motion of the two excitonic constituents.

[1]T. Kazimierczuk et al., Nature (London) 514, 343 (2014)

[2]O. Dippel, et al., Phys. Rev. A 49, 4415 (1994)