Statistical mechanics provides a framework for describing the physics of large, complex
many-body systems using only a few macroscopic parameters to determine the state of the …

Integrable quantum systems of finite size are generically robust against weak enough
integrability-breaking perturbations, but become quantum chaotic and thermalizing if the …

Using numerical exact diagonalization, we study matrix elements of a local spin operator in
the eigenbasis of two different nonintegrable quantum spin chains. Our emphasis is on the …

Strong local disorder in interacting quantum spin chains can turn delocalized eigenmodes
into localized eigenstates, giving rise to many-body localized phases. This is accompanied …

We investigate the operator growth dynamics of the transverse field Ising spin chain in one
dimension as varying the strength of the longitudinal field. An operator in the Heisenberg …

Scrambling is a key concept in the analysis of nonequilibrium properties of quantum many-
body systems. Most studies focus on its characterization via out-of-time-ordered correlation …

Out-of-time-order correlators (OTOCs) have become established as a tool to characterise
quantum information dynamics and thermalization in interacting quantum many-body …

In this work, we use the term``quantum chaos''to refer to spectral correlations similar to those
found in random matrix theory. Quantum chaos can be diagnosed through the analysis of …

The statistics of gap ratios between consecutive energy levels is a widely used tool—in
particular, in the context of many-body physics—to distinguish between chaotic and …

Matrix elements of observables in eigenstates of generic Hamiltonians are described by the
Srednicki ansatz within the eigenstate thermalization hypothesis (ETH). We study a quantum …