The recent observation of dipole-allowed P-excitons up to principal quantum numbers of n=25 in cuprous oxide has given insight into exciton states with unprecedented spectral resolution. While so far the exciton description as a hydrogen-like complex has been sufficient for cubic crystals, we demonstrate here distinct deviations: The breaking of rotational symmetry leads to mixing of high angular momentum F- and H-excitons with the P-excitons so that they can be observed in absorption. The F-excitons show a three-fold splitting that depends systematically on n, in agreement with theoretical considerations. From detailed comparison of experiment and theory we determine the cubic anisotropy parameter of the Cu2O valence band.
@article{arxiv.1503.05517,
title = {Observation of high angular momentum excitons in cuprous oxide},
author = {J. Thewes and J. Heckötter and T. Kazimierczuk and M. Aßmann and D. Fröhlich and M. Bayer and M. A. Semina and M. M. Glazov},
journal= {arXiv preprint arXiv:1503.05517},
year = {2015}
}