Scientific Projects

with

• Prof. Dr. Götz S. Uhrig (TU Dort­mund)
• Prof. Dr. Mikhail Glazov (Ioffe In­sti­tute)
• Dr. Dmitry Smirnov (Ioffe In­sti­tute)

The proj­ect is focused on the quantitative theoretical description of coherent control and dynamic spin polarization in ensembles of quantum dots induced by ultrafast pumping by optical laser pulses. We describe the radiative decay of the intermediate trion states simultaneously considering the hyperfine coupling to baths of various nuclear spins due to the presence of different isotopes, the dipole-dipole interaction among the nuclear spins, and the nuclear quadrupolar interaction induced by strain fields. Quantum mechanical and semi-classical techniques combined with stochastic approaches will be employed to assess the effect of trains of pulses and to suggest protocols for spin manipulation. Novel foci are interactions between the spins of different quantum dots and spin inertia as measured by the laser pulses with modulated circular polarization. We will study both conventional quantum dots from III-V semiconductors as well as novel types of nanosystems such as organic/inorganic perovskites.

with

• Prof. Dr. Götz S. Uhrig (TU Dort­mund)
• Prof. Dr. Mikhail Glazov (Ioffe In­sti­tute)
• Dr. Dmitry Smirnov (Ioffe In­sti­tute)

The proj­ect is focused on the quantitative theoretical description of coherent control and dynamic spin polarization in ensembles of quantum dots induced by ultrafast pumping by optical laser pulses. We describe the radiative decay of the intermediate trion states simultaneously considering the hyperfine coupling to baths of various nuclear spins due to the presence of different isotopes, the dipole-dipole interaction among the nuclear spins, and the nuclear quadrupolar interaction induced by strain fields. Quantum mechanical and semi-classical techniques combined with stochastic approaches will be employed to assess the effect of trains of pulses and to suggest protocols for spin manipulation. Novel foci are interactions between the spins of different quantum dots and spin inertia as measured by the laser pulses with modulated circular polarization. We will study both conventional quantum dots from III-V semiconductors as well as novel types of nanosystems such as organic/inorganic perovskites.

with

• Prof. Dr. Mirko Cinchetti (TU Dort­mund)
• Dr. Davide Bossini (Uni­ver­si­tät Konstanz)
• Prof. Dr. Götz S. Uhrig (TU Dort­mund)

The main goal of proj­ect B8 is to realize femtosecond spin-to-charge and charge-to-spin conversion in an AF semiconductor.The intrinsic physical complexity of our proj­ect demands both a thorough investigation of the ground state of our sample material and a tight collaboration between experiments and theory. Experimentally, we will implement a procedure allowing to disclose the real-time evolution of both the spin and charge systems. Theoretically, state-of-the-art modelling is needed to achieve a comprehensive understanding of the equilibrium and non-equilibrium re­le­vant properties, since they are both generated by many body ef­fects, electronic correlations and spin-charge coupling which are all notoriously arduous to handle.