Advanced Seminar on Condensed Matter Physics

Wintersemester 2015/2016

go to Sommersemester 2016
Prof. Dr. RĂ¼diger Klingeler
INF 227, SR 1.403
Friday 11:15-13:00 h

15.1.2016 11:15
Dr. Alexander Tsirlin, Experimental Physics VI, Center for Electronic Correlations and Magnetism, University of Augsburg, Germany
INF 227, SR 1.403

Magnetic systems with low-dimensional and frustrated geometries of exchange interactions can host unusual ground states, such as spin liquids, where no long-range magnetic order occurs even at zero temperature. The spin-liquid ground state has been predicted for several magnetic models in two dimensions, but its experimental observations are scarce.

In this talk, I will discuss the quest for the spin-liquid ground state in bulk magnetic insulators, where quantum magnetic behavior is observed. The talk will cover several simple frustrated geometries in two dimensions:

  1. real-world manifestations of the Heisenberg model on the frustrated square lattice in vanadium oxides;

  2. novel physics of the Heisenberg model on the kagome lattice probed in copper minerals;

  3. Kitaev model on the honeycomb lattice in layered van-der-Waals crystals of a-RuCl3.

I will demonstrate which challenges the bulk materials present, and which material-specific deviations from the ideal models become relevant when low-temperature magnetism is considered.