QSE Quantum Seminar: Emergent quantum coherence in random magnets allows to probe slow quantum dynamics

Please join us for the QSE Center Quantum Seminar with Prof. Markus Müller of the Paul Scherrer Institute, who will speak, on Thursday, January 18 about "Emergent quantum coherence in random magnets allows to probe slow quantum dynamics".
Location: CE 1 101

Pizzas will be available before the seminar at 12:00. All PhDs, postdocs, students, and PIs are welcome to join us.

TITLE: Emergent quantum coherence in random magnets allows to probe slow quantum dynamics

ABSTRACT: 
Local excitations in magnetic materials are usually expected to be highly incoherent, since they dephase very quickly due to mutual interactions. However, there are interesting exceptions to this common lore. Our joint experimental and theoretical study of the random rare-earth magnet LiY_{1−x}Tb_xF_4 reveals that a combination of hyperfine interactions, external magnetic fields and substantial disorder allows excitations on pairs of Tb sites to retain coherence for remarkably long times, as they can be well shielded from the dominant decoherence channels. The remaining decoherence turns out to probe the slow dynamics in the neighborhood of these degrees of freedom, which thus act as quantum sensors.This is particularly interesting as a means to probe the nearly many-body localized dynamics of strongly disordered dipolar magnets.

BIO: 
Markus Müller is a theoretical physicist working on a broad range of topics between quantum condensed matter and the statistical physics of disordered systems. He did his undergraduate studies at ETH Zürich, followed by a PhD in Orsay, Paris. After postdoctoral fellowships at Rutgers and Harvard University, and an SNF junior professorship in Geneva he joined the International Center of Theoretical Physics in Trieste in 2009, where he established himself as an expert on many-body localization, quantum glasses, quantum transport and out-of-equilibrium physics. In 2015 he moved to the Paul Scherrer Institute, where one of his main interests are the manifold magnetic incarnations of the interplay between disorder, interactions and quantum fluctuations.