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

Fuente: arXiv
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Auteurs principaux: Piccitto, Giulia, Rossini, Davide, Russomanno, Angelo
Format: Preprint
Publié: 2024
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author Piccitto, Giulia
Rossini, Davide
Russomanno, Angelo
author_facet Piccitto, Giulia
Rossini, Davide
Russomanno, Angelo
contents 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.
format Preprint
id arxiv_https___arxiv_org_abs_2402_06597
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle The impact of different unravelings in a monitored system of free fermions
Piccitto, Giulia
Rossini, Davide
Russomanno, Angelo
Quantum Physics
Statistical Mechanics
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.
title The impact of different unravelings in a monitored system of free fermions
topic Quantum Physics
Statistical Mechanics
url https://arxiv.org/abs/2402.06597