Skip navigation

Enhanced binding of a quantum particle coupled to a scalar quantized field

Oberseminar Darmstadt

Date: 05.12.2024

Time: 15:00–16:15 h

A quantum particle coupled to a quantised field behaves as if it were effectively heavier than its actual mass. Enhanced binding refers to the phenomenon that due to this effective mass of the particle, the system admits a ground state, unlike the uncoupled system. Feynman-Kac formulas allow for a probabilistic interpretation of the problem: one studies a pinned Brownian motion with a Gibbs-type reweighting. The reweighting incorporates two factors: a reward for paths that stay close to the origin and a reward for paths that look locally the same. The strength of the second reward is determined by a system parameter called the coupling strength. We are interested in the behaviour of the path at t=0 (taking the pinning at -T and T) for T large. Our main contribution is that for large enough coupling, these distributions do not vanish in a neighbourhood around 0. This can be interpreted as the particle localising, which implies the existence of a ground state in the quantum system. Joint work with Volker Betz and Mark Sellke.

Speaker

Tobias Schmidt, TU Darmstadt

Place

S2|15 Raum 315
Schlossgartenstraße 7, 64289 Darmstadt

Organizers

Technische Universität Darmstadt

Fachbereich Mathematik - Stochastik
Schlossgartenstraße 7
64289 Darmstadt
Telefon: +49 6151 16-23380
Telefax: +49 6151 16-23381
info(at)stochastik-rhein-mainde


Organizing partners

Goethe-Universität Frankfurt am Main, Johannes Gutenberg-Universität Mainz, Justus-Liebig-Universität Gießen

For this event, no registration is necessary. PDF- Link