Aldo Coraggio — SISSA #
Long-lived many-body first-detection from Stark localization #
The quantum first-detection problem concerns the statistics of the time at which a system, subject to repeated measurements, is observed in a prescribed target state for the first time. Unlike in its classical counterpart, the measurement back action intrinsic to quantum mechanics can profoundly alter the system dynamics. Here, we show that the first-detection-time statistics for the Stark Hamiltonian is particularly sensitive to the the presence of many fermions. In particular, we show that while, in the single-particle scenario, a measurement protocol that detects the particle in its initial state strongly affects the time evolution at every measurement, in the many-particle case only measurements performed at integer multiples of the Bloch-oscillation period affect the system. We further show that measurements progressively spread the fermionic density and can therefore be used for state preparation.