activity
20242026
collaborators

6 papers

cond-mat.stat-mech2026

An introduction to monitored quantum systems and quantum trajectories: spectrum, typicality, and phases

Ryusuke Hamazaki, Ken Mochizuki, Hisanori Oshima +1

Thanks to recent experimental advances in simulating and detecting quantum dynamics with high precision and controllability, our understanding of the physics of monitored quantum s…

quant-ph2025

Transitions of the Lyapunov spectrum and entanglement entropy in monitored quantum dynamics with homogeneous unitary gates

Ken Mochizuki, Ryusuke Hamazaki

We explore the Lyapunov spectrum and entanglement entropy in systems evolved by quantum measurements and spatially homogeneous unitary gates. In models with temporally random and F…

quant-ph2025

Topology and Spectrum in Measurement-Induced Phase Transitions

Hisanori Oshima, Ken Mochizuki, Ryusuke Hamazaki +1

Competition among repetitive measurements of noncommuting observables and unitary dynamics can give rise to a wide variety of entanglement phases. Here, we propose a general framew…

quant-ph2025

Threefold Way for Typical Entanglement

Haruki Yagi, Ken Mochizuki, Zongping Gong

A typical quantum state with no symmetry can be realized by letting a random unitary act on a fixed state, and the subsystem entanglement spectrum follows the Laguerre unitary ense…

quant-ph2025

Measurement-Induced Spectral Transition

Ken Mochizuki, Ryusuke Hamazaki

We show that noisy quantum dynamics exposed to weak measurements exhibit a spectral transition between gapless and gapped phases. To this end, we employ the Lyapunov spectrum obtai…

quant-ph2024

Multifractality in monitored single-particle dynamics

Kohei Yajima, Hisanori Oshima, Ken Mochizuki +1

We study multifractal properties in time evolution of a single particle subject to repeated measurements. For quantum systems, we consider circuit models consisting of local unitar…