Ultrafast Dissipative Localization of Electronic Energy in AuPt Superlattices
Abstract
Controlling the spatial distribution of absorbed optical energy is central to nanoscale photothermal chemistry, plasmonics, and ultrafast materials control. Here, we show that a metallic AuPt superlattice concentrates electronic energy in Pt within a few hundred femtoseconds, regardless of the initial energy distribution between the two constituents. Ultrafast X-ray diffraction follows this energy redistribution through the amplitude of a coherent 570 GHz superlattice phonon driven by the stress imbalance at the AuPt interfaces. Despite the nearly homogeneous absorption at 400 nm, the observed lattice motion is identical to that produced by 800 nm excitation, which is absorbed predominantly in Pt. This dissipation driven localization of energy arises from the large electronic heat capacity of Pt and rapid electronic transport through the superlattice, providing a route to femtosecond control of nanoscale energy distributions.
Related
- Electronic Structure and Superconductivity in La1.55Sr0.45CuO4/La2CuO4 Artificial High-Tc Superlattices Probed by Hard and Soft X-ray Spectroscopy
- Impurity-induced loss bursts from anomalous scale-free localization in a non-Hermitian dissipative lattice
- Scintillator-integrated microchannel plate photomultiplier tubes for ultrafast timing over keV–GeV energy scales
- High Energy Density Plasma Nanorod by Collisionless Absorption of Ultrafast Laser Pulse Inside Dielectrics
- Unveiling High-Energy Ultrafast Responses Driven by Fermi-Level Gap Opening in Charge-Density Waves
BibTeX
@misc{walz2026ultrafast,
title = {{Ultrafast Dissipative Localization of Electronic Energy in AuPt Superlattices}},
author = {C. Walz and M. Mattern and J. -E. Pudell and J. Jarecki and L. Mehner and F. -C. Weber and F. Baltrusch and S. P. Zeuschner and M. Herzog and B. Ahn and J. C. Ekström and D. Kroon and A. Jurgilaitis and J. Larsson and M. Kronseder and D. Schick and A. von Reppert and M. Bargheer},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.25426},
eprint = {2609.25426},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.25426},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Ultrafast Dissipative Localization of Electronic Energy in AuPt Superlattices
AU - C. Walz
AU - M. Mattern
AU - J. -E. Pudell
AU - J. Jarecki
AU - L. Mehner
AU - F. -C. Weber
AU - F. Baltrusch
AU - S. P. Zeuschner
AU - M. Herzog
AU - B. Ahn
AU - J. C. Ekström
AU - D. Kroon
AU - A. Jurgilaitis
AU - J. Larsson
AU - M. Kronseder
AU - D. Schick
AU - A. von Reppert
AU - M. Bargheer
PY - 2026
DA - 2026/09/21
PB - arXiv
DO - 10.48550/arxiv.2609.25426
UR - https://arxiv.org/abs/2609.25426
AB - Controlling the spatial distribution of absorbed optical energy is central to nanoscale photothermal chemistry, plasmonics, and ultrafast materials control. Here, we show that a metallic AuPt superlattice concentrates electronic energy in Pt within a few hundred femtoseconds, regardless of the initial energy distribution between the two constituents. Ultrafast X-ray diffraction follows this energy redistribution through the amplitude of a coherent 570 GHz superlattice phonon driven by the stress imbalance at the AuPt interfaces. Despite the nearly homogeneous absorption at 400 nm, the observed lattice motion is identical to that produced by 800 nm excitation, which is absorbed predominantly in Pt. This dissipation driven localization of energy arises from the large electronic heat capacity of Pt and rapid electronic transport through the superlattice, providing a route to femtosecond control of nanoscale energy distributions.
ER -