# Berlin 2014 – wissenschaftliches Programm

## Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

# Q: Fachverband Quantenoptik und Photonik

## Q 30: Poster: Photonics, laser development and applications, ultrashort laser pulses, quantum effects

### Q 30.77: Poster

### Dienstag, 18. März 2014, 16:30–18:30, Spree-Palais

**Pointer state motion of a particle in a gas environment** — •Lutz Sörgel and Klaus Hornberger — Fakultät für Physik, Universität Duisburg-Essen

A quantum test particle interacting with an ideal gas environment via collisions is a paradigmatic system for understanding the quantum-to-classical transition of particle motion. To describe the general effect of the collisions, in particular, friction and thermalization, the quantum linear Boltzmann equation [1] can be used. Two limiting cases are considered here: the limit of collisional decoherence (i.e. the marker particle is very massive) and the Brownian motion limit of many weak collisions. The pointer states for both cases are identified as the solitonic solutions of the nonlinear equation of motion associated with a particular unraveling of the master equations. Their equations of motion are determined and turn out to be the classical trajectories in phase space.

[1] B. Vacchini, K. Hornberger, Phys. Rep. 478 (2009)