Dresden 2017 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 49: Quantum Dots: Optical Properties III

HL 49.3: Talk

Wednesday, March 22, 2017, 10:00–10:15, POT 151

Light holes in quantum dots — •Vlastimil Křápek — Central European Institute of Technology, Brno University of Technology, Purkyňova 123, CZ-612 00 Brno, Czech Republic — Institute of Physical Engineering, Brno University of Technology, Technická 2, CZ-616 69 Brno, Czech Republic

The valence band edge of III-V zinc-blende semiconductors is formed by heavy and light holes. In quantum dots, the lowest confined valence state is usually contributed by the heavy holes with the weight above 90 % and by the light holes with the weight below 10 %. Thus, its properties are dominated by the heavy holes. However, there are phenomena in which the light holes play equally important or even decisive role.

In my contribution I review three such phenomena: excitonic fine structure splitting tuned by external strain field [1], quantum dot molecule with a tunable tunnel coupling [2], and brightened dark exciton [3]. I explain how the light holes couple to the heavy holes due to the quantum confinement and strain field stressing the differences between both effects.

[1] J. D. Plumhof, V. Křápek, F. Ding, K. D. Jöns, R. Hafenbrak, P. Klenovský, A. Herklotz, K. Dörr, P. Michler, A. Rastelli, and O. G. Schmidt, Phys. Rev. B 83, 121302(R) (2011).

[2] E. Zallo, R. Trotta, V. Křápek, Y. H. Huo, P. Atkinson, F. Ding, T. Šikola, A. Rastelli, and O. G. Schmidt, Phys. Rev. B 89, 241303(R) (2014).

[3] Y. H. Huo, V. Křápek, A. Rastelli, and O. G. Schmidt, submitted.