*Carte non disponible*

**Day / Time**

Date(s) - 10/11/2015*13 h 00 min - 14 h 00 min*

**Category**

Mardi 10 novembre 2015 à 13.00 heures

Ecole de physique – Auditoire Stückelberg

**Jörg Schmiedmayer**

Professor

Vienna University of Technology

Institute of Atomic and Subatomic Physics

**Atom chips: a way to study isolated quantum systems**

Atom chips allow to trap and manipulate cold atoms and create interacting isolated quantum systems.

This allow to study fundamental questions such as what is the temperature for such systems and whether such systems can thermalize after their parameters have been brutally changed (quench).

In particular interfering two isolated one-dimensional quantum gases allows to study how the coherence created between the two many body systems by a splitting process slowly degrades by coupling to the many internal degrees of freedom available

I will describe the physics of such systems and discuss the interference experiments in which the above questions can be studied. I will show in particular that for a sudden quench the system reaches a pre-thermalized state, ressembling a thermal state but for which the temperature is not relatied to the initial temperature of the system. I will also show how correlation functions up to 10th order can be experimentally measured allowing for a precise characterisation of its properties. Based on these studies we conjecture that our experiments points to a universal way through which relaxation in isolated many body quantum systems proceeds if the low energy dynamics is dominated by long lived excitations (quasi particles).