Group Seminar via Zoom: Does a disordered Heisenberg spin system thermalize?

Titus Franz, University Heidelberg
Group meeting via video conference (Zoom)
Tuesday, February 01, 9:00 am (MEZ)

Due to the Covid-19 pandemic, the group seminar will be a hybrid event, allowing participants to attend the seminar virtually and in-person. This procedure enables us to continue our research, enhance discussions and exchange important information.

Abstract:

The far-from-equilibrium dynamics of isolated spin systems is generally expected to show thermalization. As a significant exception to this rule, strongly disordered systems can retain retrievable quantum correlations for long times, leading to a rich phenomenology ranging from anomalously slow relaxation to many-body localization (MBL). While this problem is notoriously difficult to study numerically, we can experimentally probe the relaxation dynamics in an isolated spin system realized by a frozen gas of Rydberg atoms. The long-time magnetization as a function of a transverse external field shows striking features, including non-analytic behavior at zero field.
These can be understood from mean-field, perturbative, and spectral arguments. The emergence of these distinctive features seems to disagree with Eigenstate Thermalization Hypothesis (ETH), which indicates that either a better theoretical understanding of thermalization is required or ETH breaks for the here studied quench in a disordered spin system.

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