The impact of different unravelings in a monitored system of free fermions

Abstract

We consider a free-fermion chain undergoing dephasing, described by two different random-measurement protocols (unravelings): a quantum-state-diffusion and a quantum-jump one. Both protocols keep the state in a Slater-determinant form, allowing to address quite large system sizes. We find a bifurcation in the distribution of the measurement operators along the quantum trajectories, that's to say, there is a point where the shape of this distribution changes from unimodal to bimodal. The value of the measurement strength where this phenomenon occurs is similar for the two unravelings, but the distributions and the transition have different properties reflecting the symmetries of the two measurement protocols. We also consider the scaling with the system size of the inverse participation ratio of the Slater-determinant components and find a power-law scaling that marks a multifractal behaviour, in both unravelings and for any nonvanishing measurement strength.

9 pages, 5 figures; contribution to the EPJB topical issue "Quantum phase transitions and open quantum systems: A tribute to Prof. Amit Dutta"

References in corpus (57)

• Quantum trajectories and open many-body quantum systems
• Theory of the phase transition in random unitary circuits with measurements
• Measurement-induced criticality in random quantum circuits
• Critical properties of the measurement-induced transition in random quantum circuits
• Entanglement transition in a monitored free fermion chain -- from extended criticality to area law
• Scalable probes of measurement-induced criticality
• Measurement-Induced Entanglement Transitions in the Quantum Ising Chain: From Infinite to Zero Clicks
• Entanglement phase transitions in measurement-only dynamics
• Measurement and entanglement phase transitions in all-to-all quantum circuits, on quantum trees, and in Landau-Ginsburg theory
• Measurement-induced quantum criticality under continuous monitoring
• Measurement-induced criticality in (2+1)-d hybrid quantum circuits
• Entanglement Transitions from Stochastic Resetting of Non-Hermitian Quasiparticles
• SYK meets non-Hermiticity II: measurement-induced phase transition
• Entanglement Transition in the Projective Transverse Field Ising Model
• Fate of measurement-induced phase transition in long-range interactions
• Symmetry enriched phases of quantum circuits
• Entanglement and dynamics of diffusion-annihilation processes with Majorana defects
• Dissipative Floquet Dynamics: from Steady State to Measurement Induced Criticality in Trapped-ion Chains
• Emergent conformal symmetry in non-unitary random dynamics of free fermions
• Universality of entanglement transitions from stroboscopic to continuous measurements
• Growth of entanglement entropy under local projective measurements
• Universal behavior beyond multifractality of wave-functions at measurement--induced phase transitions
• Measurement-induced entanglement transitions in many-body localized systems
• Measurement-induced dynamics of many-body systems at quantum criticality
• Theory of free fermions under random projective measurements
• Measurement-induced criticality and entanglement clusters: a study of 1D and 2D Clifford circuits
• Measurement-induced phase transitions in $(d+1)$-dimensional stabilizer circuits
• Topological transitions with continuously monitored free fermions
• How Dynamical Quantum Memories Forget
• Nonlinear sigma models for monitored dynamics of free fermions
• Entanglement dynamics in hybrid quantum circuits
• Monitored Open Fermion Dynamics: Exploring the Interplay of Measurement, Decoherence, and Free Hamiltonian Evolution
• Transitions in the learnability of global charges from local measurements
• Disordered monitored free fermions
• Entanglement transitions with free fermions
• Entanglement topological invariants for one-dimensional topological superconductors
• Full counting statistics as probe of measurement-induced transitions in the quantum Ising chain
• Generalized quantum measurements with matrix product states: Entanglement phase transition and clusterization
• Topology, criticality, and dynamically generated qubits in a stochastic measurement-only Kitaev model
• Dynamics of measured many-body quantum chaotic systems
• Coherence requirements for quantum communication from hybrid circuit dynamics
• Purification Timescales in Monitored Fermions
• Fermionic Linear Optics Revisited
• Majorana Loop Models for Measurement-Only Quantum Circuits
• Neural-Network Decoders for Measurement Induced Phase Transitions
• Many-body Dynamics in Monitored Atomic Gases Without Post-Selection Barrier
• Entanglement phases, localization and multifractality of monitored free fermions in two dimensions
• Finite-time teleportation phase transition in random quantum circuits
• Entanglement transitions and quantum bifurcations under continuous long-range monitoring
• Keldysh Nonlinear Sigma Model for a Free-Fermion Gas under Continuous Measurements
• Statistical mechanics model for Clifford random tensor networks and monitored quantum circuits
• Topological entanglement properties of disconnected partitions in the Su-Schrieffer-Heeger model
• Diagrammatic method for many-body non-Markovian dynamics: memory effects and entanglement transitions
• Interactions and integrability in weakly monitored Hamiltonian systems
• Entanglement dynamics with string measurement operators
• Detecting topological phase transitions through entanglement between disconnected partitions in a Kitaev chain with long-range interactions
• Disconnected entanglement entropy as a marker of edge modes in a periodically driven Kitaev chain

Cited by in corpus (12)

• Measurement-induced transitions for interacting fermions
• Monitored fermions with conserved $\mathrm{U}(1)$ charge
• Measurement-induced symmetry restoration and quantum Mpemba effect
• Chaos and magic in the dissipative quantum kicked top
• Nonstabilizerness in the unitary and monitored quantum dynamics of XXZ-staggered and SYK models
• Nonstabilizerness of a Boundary Time Crystal
• Semiclassical Quantum Trajectories in the Monitored Lipkin-Meshkov-Glick Model
• Field theory for monitored Brownian SYK clusters
• Measurement-induced phase transition in periodically driven free-fermionic systems
• Entanglement behavior and localization properties in monitored fermion systems
• Entanglement transition in unitary system-bath dynamics
• Theoretical Limits of Protocols for Distinguishing Different Unravelings