Quantum memory devices with high storage efficiency and bandwidth are essential elements for future quantum networks. Here, we report a storage efficiency greater than 28% in a Tm3+: YAG crystal in elevated temperatur...
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Success in collaborative and competitive environments, where agents must work with or against each other, requires individuals to encode the position and trajectory of themselves and others. Decades of neurophysiologi...
This paper treats resolvent Lq estimate and maximal Lp-Lq regularity for the heat equation with various boundary conditions in an infinite layer. We need to consider two boundary conditions on upper boundary and lower...
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Light with an orbital angular momentum can strongly modify optical transition selection rules when beam size is reduced to subwavelength scale. We demonstrated a method for focusing orbital angular momentum beams belo...
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The commercial future of organic photovoltaics (OPVs) relies on their efficiency and reliability. Recent progress in the field has ensured the achievement of device efficiency comparable to those of commercial silicon...
In vivo imaging of large-scale neuronal activity plays a pivotal role in unraveling the function of the brain’s *** microscopy,a powerful tool for deep-tissue imaging,has received sustained interest in advancing its ...
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In vivo imaging of large-scale neuronal activity plays a pivotal role in unraveling the function of the brain’s *** microscopy,a powerful tool for deep-tissue imaging,has received sustained interest in advancing its speed,field of view and imaging ***,to avoid thermal damage in scattering biological tissue,field of view decreases exponentially as imaging depth *** present a suite of innovations to optimize three-photon microscopy for large field-of-view imaging at depths unreachable by two-photon *** techniques enable us to image neuronal activities of transgenic animals expressing protein calcium sensors in a~3.5-mm diameter field-of-view with single-cell resolution in the deepest cortical layer of mouse *** further demonstrate simultaneous large field-of-view two-photon and three-photon imaging,subcortical imaging in the mouse brain,and whole-brain imaging in adult *** demonstrated techniques can be integrated into typical multiphoton microscopes to enlarge field of view for system-level neural circuit research.
Counterfactuals, or modified inputs that lead to a different outcome, are an important tool for understanding the logic used by machine learning classifiers and how to change an undesirable classification. Even if a c...
Counterfactuals, or modified inputs that lead to a different outcome, are an important tool for understanding the logic used by machine learning classifiers and how to change an undesirable classification. Even if a counterfactual changes a classifier's decision, however, it may not affect the true underlying class probabilities, i.e. the counterfactual may act like an adversarial attack and "fool" the classifier. We propose a new framework for creating modified inputs that change the true underlying probabilities in a beneficial way which we call Trustworthy Actionable Perturbations (TAP). This includes a novel verification procedure to ensure that TAP change the true class probabilities instead of acting adversarially. Our framework also includes new cost, reward, and goal definitions that are better suited to effectuating change in the real world. We present PAC-learnability results for our verification procedure and theoretically analyze our new method for measuring reward. We also develop a methodology for creating TAP and compare our results to those achieved by previous counterfactual methods.
Monoclinic β-Ga2O3 films grown on c-plane sapphire have been shown to exhibit six (2¯01)-oriented domains, which are equally spaced by rotation around the surface normal and equally sized by volume that render t...
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Monoclinic β-Ga2O3 films grown on c-plane sapphire have been shown to exhibit six (2¯01)-oriented domains, which are equally spaced by rotation around the surface normal and equally sized by volume that render the film optical response effectively uniaxial. We derive and discuss an optical model suitable for ellipsometry data analysis of such films. We model mid- and far-infrared ellipsometry data from undoped and electrically insulating films with an effective uniaxial dielectric tensor based on projections of all phonon modes within the rotation domains parallel and perpendicular to the sample normal, i.e., to the reciprocal lattice vector g2¯01. Two effective response functions are described by the model, and found sufficient to calculate ellipsometry data that best match measured ellipsometry data from a representative film. We propose to render either effective dielectric functions, or inverse effective dielectric functions, each separately for electric field directions parallel and perpendicular to g2¯01, by sums of Lorentz oscillators, which permit determination of either sets of transverse optical phonon-mode parameters, or sets of longitudinal optical phonon-mode parameters, respectively. Transverse optical modes common to both dielectric functions can be traced back to single-crystal modes with Bu character, while modes with Au character appear only within the dielectric function for polarization perpendicular to the sample surface. The thereby obtained parameter sets reveal all phonon modes anticipated from averaging over the sixfold-rotation domains of single crystal β-Ga2O3, but with slightly shifted transverse optical, and completely different longitudinal optical phonon modes. Structural analysis of the film revealed virtually strain-free material. We suggest small crystal grains and high density of grain boundaries as a possible origin for the observed transverse optical phonon-frequency shifts with respect to bulk material. The differences in longit
Selective thermal emitters can boost the efficiency of heat-to-electricity conversion in thermophotovoltaic systems only if their spectral selectivity is high. We demonstrate a non-Hermitian metasurface-based selectiv...
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