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We investigate the electronic shot noise produced by nanowires of β-Ta, an archetypal “bad” metal with resistivity near the Ioffe–Regel localization limit. The Fano factor characterizing the shot noise exhibits a strong dependence on temperature and is suppressed compared to the expectations for quasiparticle diffusion, but hopping transport is ruled out by the analysis of scaling with the nanowire length. These anomalous behaviors closely resemble those of strange metal nanowires, suggesting that β-Ta may host a correlated electron liquid. This material provides an accessible platform for exploring exotic electronic states of matter.more » « lessFree, publicly-accessible full text available February 1, 2026
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Abstract Photoluminescence from spatially inhomogeneous plasmonic nanostructures exhibits fascinating wavelength-dependent nonlinear behaviors due to the intraband recombination of hot electrons excited into the conduction band of the metal. The properties of the excited carrier distribution and the role of localized plasmonic modes are subjects of debate. In this work, we use plasmonic gap-mode resonators with precise nanometer-scale confinement to show that the nonlinear photoluminescence behavior can become dominated by non-thermal contributions produced by the excited carrier population that strongly deviates from the Fermi-Dirac distribution due to the confinement-induced large-momentum free carrier absorption beyond the dipole approximation. These findings open new pathways for controllable light conversion using nonequilibrium electron states at the nanoscale.more » « less
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Excitation and detection of coherent nanoscale spin waves via extreme ultraviolet transient gratingsThe advent of free electron lasers has opened the opportunity to explore interactions between extreme ultraviolet (EUV) photons and collective excitations in solids. While EUV transient grating spectroscopy, a noncollinear four-wave mixing technique, has already been applied to probe coherent phonons, the potential of EUV radiation for studying nanoscale spin waves has not been harnessed. Here we report EUV transient grating experiments with coherent magnons in Fe/Gd ferrimagnetic multilayers. Magnons with tens of nanometers wavelengths are excited by a pair of femtosecond EUV pulses and detected via diffraction of a probe pulse tuned to an absorption edge of Gd. The results unlock the potential of nonlinear EUV spectroscopy for studying magnons and provide a tool for exploring spin waves in a wave vector range not accessible by established inelastic scattering techniques.more » « less
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In viscous dynamics, velocity is proportional to the force. An ideal memristor is a device whose resistance changes at a rate proportional to the driving input. We present a proof-of-principle demonstration of the connection between viscous dynamics and memristive functionality by utilizing a thin-film ferromagnet/antiferromagnet bilayer, where viscous magnetization dynamics results from the frustration at the magnetic interface, and driving is provided by an external magnetic field. Thanks to the atomic scale of frustration effects, the presented approach is amenable to downscaling. It can also be adapted for electronic driving by spin torque, making it attractive for applications in neuromorphic circuits.more » « less
