Claudia Artiaco

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During the time evolution of many-body quantum systems entanglement grows rapidly, limiting exact simulations
to small-scale systems and small timescales. Quantum information tends, however, to flow towards larger
scales without returning to local scales, such that its detailed large-scale structure does not directly affect local
observables. This allows for the removal of large-scale quantum information in a way that preserves all local
observables and gives access to large-scale and large-time quantum dynamics. To this end, in [2] we proposed
a novel approach that uses the information lattice [1] to organize quantum information into different scales,
allowing us to define local information and information currents which we employ to systematically discard long-
range quantum correlations in a controlled way. The resulting algorithm, which we refer to as local-information
time evolution (LITE), is highly versatile and suitable for investigating large-scale many-body quantum dynamics
in both closed and open systems with diverse hydrodynamic behaviors.
In this talk, I will introduce the information lattice and present results obtained with LITE for the energy
transport in the mixed-field Ising model and the magnetization transport in the XX spin chain with onsite
dephasing, where we accurately determine the power-law exponents and the diffusion constants [2].
Furthermore, I will discuss how the information lattice can be employed to universally characterize generic
many-body quantum states and compute intrinsic correlation lengths [4].
References:
[1] T. Klein Kvorning, L. Herviou, and J. H. Bardarson, Time-evolution of local information: Thermalization
dynamics of local observables, SciPost Phys. 13, 080 (2022).
[2] C. Artiaco, C. Fleckenstein, D. Aceituno Chávez, T. Klein Kvorning, and J. H. Bardarson, Efficient Large-
Scale Many-Body Quantum Dynamics via Local-Information Time Evolution, PRX Quantum 5 (2), 020352
(2024).
[3] K. Harkins et al., Nanoscale engineering and dynamical stabilization of mesoscopic spin textures,
arXiv:2310:05635.
[4] C. Artiaco, T. Klein Kvorning, D. Aceituno Chávez, L. Herviou, and J. H. Bardarson, Universal
Characterization of Quantum Many-Body States through Local Information, arXiv2410:10971.

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KTH Royal Institute of Technology, Stockholm
0.03
Contact: Silvia Pappalardi