Purification Timescales in Monitored Fermions

Abstract

We investigate the crucial role played by a global symmetry in the purification timescales and the phase transitions of monitored free fermionic systems separating a mixed and a pure phase. Concretely, we study Majorana and Dirac circuits with ${\mathbb{Z}}_2$ and U(1) symmetries, respectively. In the first case, we demonstrate the mixed phase of $L$ sites has a purification timescale that scales as ${\tau }_P\sim L\ln L$. At $1\ll t\ll {\tau }_P$ the system attains a finite residual entropy, that we use to unveil the critical properties of the purification transition. In contrast, free fermions with U(1) manifest a sublinear purification timescale at any measurement rate and an apparent Berezinskii-Kosterlitz-Thouless criticality. We find the mixed phase is characterized by ${\tau }_P\sim L^{\alpha (p)}$, with a continuously varying exponent $\alpha (p)<1$.

7 pgase, 3 figures, 3 pages of supplementary material

References in corpus (26)

• Thermalization and its mechanism for generic isolated quantum systems
• Anderson Transitions
• Random Quantum Circuits
• Critical properties of the measurement-induced transition in random quantum circuits
• Postselection-free entanglement dynamics via spacetime duality
• Experimental Realization of a Measurement-Induced Entanglement Phase Transition on a Superconducting Quantum Processor
• Measurement-induced phase transitions in $(d+1)$-dimensional stabilizer circuits
• Volume-to-Area Law Entanglement Transition in a non-Hermitian Free Fermionic Chain
• Eigenstate Thermalization Hypothesis and Free Probability
• Monitored Open Fermion Dynamics: Exploring the Interplay of Measurement, Decoherence, and Free Hamiltonian Evolution
• Solvable model of deep thermalization with distinct design times
• Controlling entanglement at absorbing state phase transitions in random circuits
• Transitions in the learnability of global charges from local measurements
• Entanglement transitions with free fermions
• Entanglement Steering in Adaptive Circuits with Feedback
• Generalized Deep Thermalization for Free Fermions
• Entanglement enhanced metrology with quantum many-body scars
• Topological order and entanglement dynamics in the measurement-only XZZX quantum code
• Triviality of quantum trajectories close to a directed percolation transition
• Volume-law to area-law entanglement transition in a non-unitary periodic Gaussian circuit
• Measurement induced entanglement transition in two dimensional shallow circuit
• Infinite-randomness criticality in monitored quantum dynamics with static disorder
• KPZ physics and phase transition in a classical single random walker under continuous measurement
• Bridging the gap between classical and quantum many-body information dynamics
• Entanglement structure in the volume-law phase of hybrid quantum automaton circuits
• A universal crossover in quantum circuits governed by a proximate classical error correction transition

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• Entanglement Dynamics in Monitored Systems and the Role of Quantum Jumps
• Measurement-induced transitions beyond Gaussianity: a single particle description
• Entanglement transitions and quantum bifurcations under continuous long-range monitoring
• Measurement-induced transitions for interacting fermions
• Interactions and integrability in weakly monitored Hamiltonian systems
• Postselection-free learning of measurement-induced quantum dynamics
• Measurement-induced symmetry restoration and quantum Mpemba effect
• Density and current statistics in boundary-driven monitored fermionic chains
• Measurement-induced phase transition in a single-body tight-binding model
• Enhanced Entanglement in the Measurement-Altered Quantum Ising Chain
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• Generalized Zeno effect and entanglement dynamics induced by fermion counting
• Localization, fractality, and ergodicity in a monitored qubit
• The impact of different unravelings in a monitored system of free fermions
• A Dyson Brownian motion model for weak measurements in chaotic quantum systems
• Measurement-induced multipartite-entanglement regimes in collective spin systems
• Universal Stochastic Equations of Monitored Quantum Dynamics
• Entanglement transitions induced by quantum-data collection
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• Measurement-Induced Phase Transition in State Estimation of Chaotic Systems and the Directed Polymer
• Topology and Spectrum in Measurement-Induced Phase Transitions
• Field theory for monitored Brownian SYK clusters
• Semiclassical Quantum Trajectories in the Monitored Lipkin-Meshkov-Glick Model
• Multipartite entanglement structure of monitored quantum circuits
• Measurement-induced phase transitions for free fermions in a quasiperiodic potential
• Monitored Fluctuating Hydrodynamics
• Purification Dynamics in a Continuous-time Hybrid Quantum Circuit Model
• Random Quantum Circuits with Time-Reversal Symmetry
• Quantum dynamics of monitored free fermions: Evolution of quantum correlations and scaling at measurement-induced phase transition
• Entanglement transition in unitary system-bath dynamics
• Symmetry and Topology of Monitored Quantum Dynamics
• Transitions of the Lyapunov spectrum and entanglement entropy in monitored quantum dynamics with homogeneous unitary gates
• Absence of measurement- and unraveling-induced entanglement transitions in continuously monitored one-dimensional free fermions
• Controlled Zeno-Induced Localization of Free Fermions in a Quasiperiodic Chain