Berlin 2018 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 33: Poster Session III

HL 33.26: Poster

Wednesday, March 14, 2018, 17:30–19:30, Poster F

A series of "fractional" peaks in multiple paramagnetic resonance Raman scattering by (Cd,Mn)Te quantum wells — Alexei Koudinov^1,2, Alexander Knapp³, Grzegorz Karczewski⁴, •Sebastian Elsässer³, and Jean Geurts³ — ¹Spin Optics Laboratory, St.-Petersburg State University, St.-Petersburg, Russia — ²A.F. Ioffe Physico-Technical Institute of RAS, Russia — ³Physikalisches Institut (EP3), Universität Würzburg, Germany — ⁴Institute of Physics, Polish Academy of Sciences, Warsaw, Poland

Diluted magnetic semiconductors (DMS) are employed as a ground for the analysis of spin interactions between the band charge-carriers and the localized spin moments of magnetic ions. In 1995, multiple paramagnetic resonance (MPR) Raman scattering was discovered in narrow QWs of the (Cd,Mn,Mg)Te family: a large number of equidistant Raman repetitions, with energy shifts being integer multiples of the Zeeman splitting of the intra-shell Mn 3d5 electrons. We report on a previously unknown series of B-field dependent Raman lines in MPR conditions in a model DMS QW nanostructure. The observed series of lines shows up in the gaps between the main MPR peaks in a narrow range of B-fields (around 6 T) and seems to manifest a fractional effect: a spin flip of a half-integer number of Mn 3d5 electrons. The peaks reveal remarkably weak dependence of the intensity on the peak number. We demonstrate some main peculiarities of the observed series of lines, discuss the appropriateness of the fractional- as well as alternative interpretations and we discuss steps towards a further exploration of the effect.