ContactDepartment of Physics
University of Basel
CH-4056 Basel, Switzerland
|2010 - Present||PhD student at the University of Basel, under the supervision of Prof. Dr. Daniel Loss|
|2009 - 2010||Diploma thesis under the supervision of Prof. Dr. Guido Burkard|
|2004 - 2010||Undergraduate studies in Physics at the University of Konstanz|
- Spin relaxation and decoherence
- Holes in semiconductor nanostructures
PublicationsShow all abstracts.
|1.||Tunable g factor and phonon-mediated hole spin relaxation in Ge/Si nanowire quantum dots|
|Franziska Maier, Christoph Kloeffel, and Daniel Loss.|
Phys. Rev. B 87, 161305(R); arXiv:1302.5027.
We theoretically consider g factor and spin lifetimes of holes in a longitudinal Ge/Si core/shell nanowire quantum dot that is exposed to external magnetic and electric fields. For the ground states, we find a large anisotropy of the g factor which is highly tunable by applying electric fields. This tunability depends strongly on the direction of the electric field with respect to the magnetic field. We calculate the single-phonon hole spin relaxation times T1 for zero and small electric fields and propose an optimal setup in which very large T1 of the order of tens of milliseconds can be reached. Increasing the relative shell thickness or the longitudinal confinement length prolongs T1 further. In the absence of electric fields, the dephasing vanishes and the decoherence time T2 is determined by T2 = 2 T1.
|2.||Effect of strain on hyperfine-induced hole-spin decoherence in quantum dots|
|Franziska Maier and Daniel Loss.|
Phys. Rev. B 85, 195323; arXiv:1203.3876.
We theoretically consider the effect of strain on the spin dynamics of a single heavy-hole (HH) confined to a self-assembled quantum dot and interacting with the surrounding nuclei via hyperfine interaction. Confinement and strain hybridize the HH states, which show an exponential decay for a narrowed nuclear spin bath. For different strain configurations within the dot, the dependence of the spin decoherence time $T_2$ on external parameters is shifted and the non-monotonic dependence of the peak is altered. Application of external strain yields considerable shifts in the dependence of $T_2$ on external parameters. We find that external strain affects mostly the effective hyperfine coupling strength of the conduction band (CB), indicating that the CB admixture of the hybridized HH states plays a crucial role in the sensitivity of $T_2$ on strain.