Inelastic spin-photon interactions in spectroscopy of Raman scattering and polarization noise

• Applicant: Professor Dr. Jean Geurts
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2017 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 322983129

• Final Report Year: 2020

Final Report Abstract

The main goal of this project was the investigation of the correlation between spin flip Raman spectroscopy (SFRS) and spin noise spectroscopy (SNS). This study took place in a German-Russian partnership with Dr. A.V. Koudinov and coworkers (St. Petersburg), where the SNS experiments were performed. For the SFRS- and the SNS experiments the same set of (Cd,Mn)Te/(Cd,Mg)Te quantum well samples was employed. For the first time SNS signals were detected in samples showing multiple SFRS. In parallel, theoretical descriptions of both phenomena were developed for the first time from common basics. However, up to now, a direct application of this description to the experimental results is hampered by the influence of nuclear (hyperfine) effects in the SNS experiments. For a necessary straightforward in-depth matching the extension of the B-field range to ~500 mT, along with the corresponding extension of the SNS instrumental bandwidth is required, which is currently in progress. In the framework of the SFRS experiments a significant experimental upgrade allowed the novel high- resolution observation of multiple spin flip features from Mn pairs with four different spatial geometries. Their evaluation enabled the determination of the corresponding geometry-dependent Mn-Mn exchange constants with a hitherto unknown accuracy of ±0.05 K. Moreover, this method offers the potential for application to other diluted magnetic semiconductors.

Publications

• Series of “fractional” peaks in multiple paramagnetic resonance Raman scattering, Phys. Rev. B 96, 241303(R) (2017)
  A.V. Koudinov, A. Knapp, G. Karczewski, and J. Geurts
  
• High-resolution resonance spin-flip Raman spectroscopy of pairs of manganese ions in a CdTe quantum well, Phys. Rev. B 101, 241301(R) (2020)
  R. V. Cherbunin, V. M. Litviak, I. I. Ryzhov, A. V. Koudinov , S. Elsässer, A. Knapp, T. Kiessling, J. Geurts, S. Chusnutdinow, T. Wojtowicz, and G. Karczewski