Ramanujan Auditorium

Dynamical phases of quantum matter in measurement-unitary hybrid dynamics

Sthitadhi Roy

ICTS-TIFR

In general, unitary quantum dynamics in many-body systems leads to information scrambling accompanied by unbounded growth of
entanglement entropies. In layperson’s terms, this corresponds to information present locally in the state getting hidden in complicated
non-local correlations. This is a fundamental obstruction to stabilising new kinds of order or phases of quantum matter which are
manifestly out of equilibrium. In this talk, first I will show that quantum measurements can be used to arrest the entanglement growth
and in fact, drive a dynamical phase transition into a phase where the entanglement continues to be small at all times. After establishing
this, in the second part of the talk, I will describe how specific measurement protocols can be used to absolutely stabilise spatiotemporal
order of the discrete time crystal variety. I will conclude with a brief discussion of how these protocols can be implemented on current
NISQ devices.