Spikes in Poissonian quantum trajectories

Physical Review A: Atomic, Molecular, and Optical physics. 2025. Vol. 111. No. 4. Article 042215.

Sherry A., Бернардан С. Ж., Dhar A., Aritra K., Chetrite R.

We consider the dynamics of a continuously monitored qubit in the limit of strong measurement
rate where the quantum trajectory is described by a stochastic master equation with Poisson noise.
Such limits are expected to give rise to quantum jumps between the pointer states associated with
the non-demolition measurement. A surprising discovery in earlier work [Tilloy et al., Phys. Rev.
A 92, 052111 (2015)] on quantum trajectories with Brownian noise was the phenomena of spikes
observed in between the quantum jumps. Here, we show that spikes are observed also for Poisson
noise. We consider three cases where the non-demolition is broken by adding, to the basic strong
measurement dynamics, either unitary evolution or thermal noise or additional measurements. We
present a complete analysis of the spike and jump statistics for all three cases using the fact that
the dynamics effectively corresponds to that of stochastic resetting. We provide numerical results
to support our analytic results.

Ключевые слова: Quantum measurements, Quantum Zeno dynamics, Quantum correlations, foundations & formalism