Alladi Ramakrishnan Hall

Slow quenches, dynamical phase transitions and emergent topology

Amit Dutta

Indian Institute of Technology Kanpur

When a quantum many body system is driven slowly or suddenly across a
quantum critical point, there are non-analyticities in the
subsequent real time evolution of the system manifested in the logarithm
of the Loschmidt echo. These non-analyticities occurring at different
instants of time are so called "dynamical phase transitions".
Analyzing the sudden and slow quenching of a transverse
XY chain, we illustrate what is called a dynamical phase transition.
We also elaborate how a topological order parameter
(given in terms of the Pancharatnam geometric phase) emerge characterizing
such non-equilibrium transitions.