Measurement induced phase transitions in monitored fermion systems
Friday 10 December 2021, 3:00pm to 4:00pm
Venue
MS Teams eventOpen to
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Condensed Matter on-line seminar
A wave function exposed to measurements undergoes pure state dynamics, with deterministic unitary and probabilistic measurement induced state updates, defining a quantum trajectory. For many-particle systems, the competition of these different elements of dynamics can give rise to a scenario similar to quantum phase transitions. However, due to the stochastic nature of the wave function, this type of phase transition does not manifest itself in common observables obtained from the averaged density matrix, but instead mainly has been detected via the dynamics of entanglement.
Here we establish a novel type of entanglement transition between a regime of logarithmic entanglement growth, and a quantum Zeno regime obeying an area law, in continuously monitored fermion dynamics. We identify the relevant degrees of freedom driving the phase transition, and derive an effective field theory for it. This yields both a physical picture in terms of a depinning from the measurement operator eigenstates induced by unitary dynamics, and places it into the BKT universality class.
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Speaker
Sebastian Diehl (University of Cologne)
Contact Details
Name | Dr. Michael Thompson |