Erlangen 2018 – wissenschaftliches Programm
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A: Fachverband Atomphysik
A 17: Atoms in external fields
A 17.2: Vortrag
Montag, 5. März 2018, 16:30–16:45, K 2.019
Excitonic Spectra of Giant-Dipole States in Cuprous Oxide — Markus Kurz and •Stefan Scheel — Institut für Physik, Universität Rostock, Albert-Einstein-Straße 23, D-18059 Rostock
Excitons are the quanta of 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 present the eigenspectra of a novel species of excitons when exposed to crossed electric and magnetic fields. In particular, we present the eigenenergies of giant-dipole excitons in Cu20 in crossed fields [3]. We calculate the excitonic spectra within several theoretical approaches. We verify that stable bound excitonic giant-dipole states are only possible in the case of strong magnetic fields, as this is the only regime providing sufficiently deep potential wells for their existence. Comparing both analytic as well as numerical calculations we obtain excitonic giant-dipole spectra with level spacings up to 100 µ eV.
[1]T. Kazimierczuk et al., Nature (London) 514, 343 (2014)
[2]O. Dippel, et al., Phys. Rev. A 49, 4415 (1993)
[3]M. Kurz, et al., Phys. Rev. B 95, 245205 (2017)