arXiv subjects

P. Vogl

Publications and source records attributed to P. Vogl.

2 recordsLinked to original sources

arXiv2009

Gate control of low-temperature spin dynamics in two-dimensional hole systems

We have investigated spin and carrier dynamics of resident holes in high-mobility two-dimensional hole systems in GaAs/Al$_{0.3}$Ga$_{0.7}$As single quantum wells at temperatures down to 400 mK. Time-resolved Faraday and Kerr rotation, as well as time-resolved photoluminescence spectroscopy are utilized in our study. We observe long-lived hole spin dynamics that are strongly temperature dependent, indicating that in-plane localization is crucial for hole spin coherence. By applying a gate voltage, we are able to tune the observed hole g factor by more than 50 percent. Calculations of the hole g tensor as a function of the applied bias show excellent agreement with our experimental findings.

cond-mat.mes-hall↗

arXiv1999

Quasi-harmonic vs. ``exact'' surface free energies of Al: a systematic study employing a new interatomic potential

We discuss a computationally efficient classical many-body potential designed to model the Al-Al interaction in a wide range of bonding geometries. We show that the potential yields results in properties in excellent agreement with experiment and ab initio results for a number of bulk and surface properties, among others for surface and step formation energies, and self-diffusion barriers. As an application, free energy calculations are performed for the Al (100) surface by Monte Carlo thermodynamic integration and the quasi-harmonic approximation. Comparison of the latter approximation with the reference Monte Carlo results provides informations on its range of applicability to surface problems at high temperatures.

cond-mat.mtrl-sci↗