Personal tools
/ Research / Condensed Matter Physics / CMP Events / Order by singularity

Order by singularity

— filed under: ,
Date and time Aug 16, 2019
from 11:00 AM to 12:30 PM
Location 60 St. George Street, MP 1115
Host Yong Baek Kim

Ganesh Ramachandran

Institute of Mathematical Sciences, Chennai

We present a paradigm for effective descriptions of quantum magnets. Typically, a magnet has many classical ground states — configurations of spins (as classical vectors) that have the least energy. The set of all such ground states forms an abstract space. At low energies, the physics of the quantum magnet maps to that of a single particle moving in this space. A particularly interesting example is the XY tetrahedral magnet. Here, the ground state space is a 'non-manifold’ as it self-intersects at singularities. These singularities behave like impurity potentials to create bound states. The low energy physics of the magnet is entirely determined by these bound states. We call this phenomenon 'order by singularity’. This leads to a preference for certain classical ground states over others purely due to topology. Unlike order-by-disorder, this effect persists even in the classical limit.
Reference: arXiv:1903.01499
Contact Name
Document Actions