Berlin 2024 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 32: Spin Phenomena in Semiconductors

HL 32.1: Talk

Wednesday, March 20, 2024, 15:00–15:15, EW 015

Hole spin coherence in InAs/InAlGaAs self-assembled quantum dots emitting at telecom wavelengths. — Eiko Evers¹, Natalia Kopteva¹, •Vitalie Nedelea¹, A Kors², Ranbir Kaur², Johann Reithmaier², Mohamed Benyoucef², Manfred Bayer¹, and Alex Greilich¹ — ¹Experimentelle Physik 2, Technische Universität Dortmund, 44221 Dortmund, Germany — ²Institute of Nanostructure Technologies and Analytics (INA), CINSaT, University of Kassel, D-34132 Kassel, Germany

We report measurements of the longitudinal and transverse spin relaxation times of holes in an ensemble of self-assembled InAs/InAlGaAs quantum dots (QDs) emitting in the telecom spectral range. The spin coherence of a single carrier is determined by spin mode locking in the inhomogeneous ensemble of QDs. By modelling the signal, the hole spin coherence time can be extracted to be in the range of T2 = 0.02 - 0.4 *s. The longitudinal spin relaxation time T1 = 0.5 *s is measured by the spin inertia method. Using the spin mode-locking method, we could deter mine the range of the achievable spin coherence of holes, which exceed previously measured values in similar types of QDs by at least an order of magnitude. The longitudinal spin lifetime of 0.5 μs is also extended and currently provides the upper limit for the spin coherence.

Keywords: Quantum coherence; Quantum repeaters; Spin dynamics; Spin polarization; Spin relaxation