Patrice Kolb


Last Name

Kolb

First Name

Patrice

ORCID

0000-0003-3946-7671

Organisational unit

03925 - Luisier, Mathieu / Luisier, Mathieu

Filters

2023 - 20253
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Publications 1 - 3 of 3
  • Stability of the Many-Body Scars in Fermionic Spin-1/2 Models
    Item type: Journal Article
    Kolb, Patrice; Pakrouski, Kiryl (2023)
    PRX Quantum
    We study the stability of the many-body scars in spin-1/2 fermionic systems under the most typical perturbations in relevant materials. We find that some families of scars are completely insensitive to certain perturbations. In some other cases, they are stable to the first order in perturbation theory. Our analytical results apply to a large class of Hamiltonians that are known [K. Pakrouski et al., Phys. Rev. Res. 3, 043156 (2021)] to support exact many-body scars. For the numerical calculations, we choose the deformed t-J-U model, which includes both Heisenberg and Hubbard interactions. We propose two new stability measures that are based on physical observables rather than the fidelity to the exact initial wave function. They enable the experimental detection of scars and are more reliable from theoretical and numerical perspectives. One of these measures may potentially find applications in other systems where the exact many-body scars are equally spaced in energy. In small systems and at small perturbations, a regime particularly relevant for quantum simulators, we identify and describe an additional stability exhibited by the many-body scars. For larger perturbation strengths, we observe a distinct mode of ergodicity breaking that is consistent with many-body localization.
  • Melting, Bubblelike Expansion, and Explosion of Superheated Plasmonic Nanoparticles
    Item type: Journal Article
    Dold, Simon; Reichenbach, Thomas; Colombo, Alessandro; et al. (2025)
    Physical Review Letters
    We report on time-resolved coherent diffraction imaging of gas-phase silver nanoparticles, strongly heated via their plasmon resonance. The x-ray diffraction images reveal a broad range of phenomena for different excitation strengths, from simple melting over strong cavitation to explosive disintegration. Molecular dynamics simulations fully reproduce this behavior and show that the heating induces rather similar trajectories through the phase diagram in all cases, with the very different outcomes resulting solely from whether and where the stability limit of the metastable superheated liquid is crossed.
  • Three-dimensional femtosecond snapshots of isolated faceted nanostructures
    Item type: Journal Article
    Colombo, Alessandro; Dold, Simon; Kolb, Patrice; et al. (2023)
    Science Advances
    The structure and dynamics of isolated nanosamples in free flight can be directly visualized via single-shot coherent diffractive imaging using the intense and short pulses of x-ray free-electron lasers. Wide-angle scattering images encode three-dimensional (3D) morphological information of the samples, but its retrieval remains a challenge. Up to now, effective 3D morphology reconstructions from single shots were only achieved via fitting with highly constrained models, requiring a priori knowledge about possible geometries. Here, we present a much more generic imaging approach. Relying on a model that allows for any sample morphology described by a convex polyhedron, we reconstruct wide-angle diffraction patterns from individual silver nanoparticles. In addition to known structural motives with high symmetries, we retrieve imperfect shapes and agglomerates that were not previously accessible. Our results open unexplored routes toward true 3D structure determination of single nanoparticles and, ultimately, 3D movies of ultrafast nanoscale dynamics.
Publications 1 - 3 of 3