Proc Natl Acad Sci U S A
December 2024
Recent experiments suggest a new paradigm toward novel colossal magnetoresistance (CMR) in a family of materials EuM[Formula: see text]X[Formula: see text] (M [Formula: see text] Cd, In, Zn; X [Formula: see text] P, As), distinct from the traditional avenues involving Kondo-Ruderman-Kittel-Kasuya-Yosida crossovers, magnetic phase transitions with structural distortions, or topological phase transitions. Here, we use angle-resolved photoemission spectroscopy and density functional theory calculations to explore their origin, particularly focusing on EuCd[Formula: see text]P[Formula: see text]. While the low-energy spectral weight royally tracks that of the resistivity anomaly near the temperature with maximum magnetoresistance ([Formula: see text]) as expected from transport-spectroscopy correspondence, the spectra are completely incoherent and strongly suppressed with no hint of a Landau quasiparticle.
View Article and Find Full Text PDFMotivated by the pair-density-wave (PDW) state found in the one-dimensional Kondo-Heisenberg chain, we report on a determinant quantum Monte Carlo study of pair fields for a two-dimensional half-filled Hubbard layer coupled to an itinerant, noninteracting layer with one electron per site. In a specific range of interlayer hopping, the pairing vertex associated with PDW order becomes more attractive than that for uniform d-wave pairing, although both remain subdominant to the leading antiferromagnetic correlations at half filling. Our result sheds light on where one potentially may find a PDW state in such a model.
View Article and Find Full Text PDFUnderstanding electron-phonon coupling in noncentrosymmetric materials is critical for controlling the internal fields which give rise to Rashba interactions. We apply time- and angle-resolved photoemission spectroscopy (trARPES) to study coherent phonons in the surface and bulk regions of the polar semiconductor BiTeCl. Aided by ab initio calculations, our measurements reveal the coupling of out-of-plane A_{1} modes and an in-plane E_{2} mode.
View Article and Find Full Text PDFACS Appl Mater Interfaces
September 2024
In this work, we build a computationally inexpensive, data-driven model that utilizes atomistic structure information to predict the reactivity of interfaces between any candidate solid-state electrolyte material and a Li metal anode. This model is trained on data from molecular dynamics (AIMD) simulations of the time evolution of the solid electrolyte-Li metal interfaces for 67 different materials. Predicting the reactivity of solid-state interfaces with techniques remains an elusive challenge in materials discovery and informatics, and previous work on predicting interfacial compatibility of solid-state Li-ion electrolytes and Li metal anodes has focused mainly on thermodynamic convex hull calculations.
View Article and Find Full Text PDFA 36-year-old woman with a medical history of opioid use disorder and frequent urinary tract infections presented to the ED from her opioid use disorder clinic, where she was found to have an oxygen saturation by pulse oximetry (Spo) of 82% on room air. Starting 3 days before presentation, the patient's family noted worsening pale complexion and blue lips at rest. These findings of cyanosis had occurred a few times before and always resolved within a couple days without any medical intervention.
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