Abstract :

Spin liquids are intriguing magnetic states of matter that are neither ordered (like ferromagnets or antiferromagnets) nor disordered (like paramagnets), and require new concepts such as fractionalised excitations and emergent gauge fields for their description. A complete understanding of such states is still lacking and many fundamental questions remain. Quenched disorder can nucleate defects with unusual properties and thus reveal the hidden collective excitations of such spin liquid states. In this talk, I will first give a brief introduction to spin liquids and then explain how disorder can act as a powerful probe for the diagnosis of certain types of spin liquids by (a) producing spin textures with fractionalised moments and (b) leading to a topological spin glass which shows signatures of both spin liquidity and glassiness.

ABOUT THE SPEAKER:

Arnab Sen obtained his B.Sc. (Hons) in physics from St. Stephen's College, Delhi in 2003 and Ph.D. from the TIFR in 2009. He was then research associate at Boston University from 2009 to 2011 and postdoctoral fellow at the Max Planck Institute for the Physics of Complex Systems from 2011 to 2013. In September 2013, he became a faculty member at the Department of Theoretical Physics in the Indian Association for the Cultivation of Science, Kolkata. His research interests are mainly in the fields of strongly correlated systems and statistical mechanics. Some recent focus areas of his research include frustrated magnets and spin liquids, unconventional phase transitions beyond the Landau Ginzburg paradigm, entanglement properties of many-body systems and numerical many-body physics.