Justification of the effective fractional Coulomb energy and the extended Brinkman-Rice picture

In order to calculate the effective mass of quasiparticles for a strongly correlated metallic system in which the number of carriers, n, is less than that of atoms (or lattices), l, the metallic system is averaged by one effective charge per atom over all atomc sites. The effective charge of carriers, =(n/l)e={rho}e, and the on-site Coulomb repulsion, U={rho}^2={rho}^2kU_c, are defined and are justified by means of measurement. {rho} is band filling and k is the correlation strength. The effective mass, m^*/m=1/(1-k^2{rho}^4), calculated by the Gutzwiller variational theory, is regarded as the average of the true effective mass in the Brinkman-Rice (BR) picture and is the effect of measurement. The true effective mass has the same value irrespective of {rho}, and is not measured experimentally. The true correlation strength of the BR picture is evaluated as 0.90<k_{BR}<1 for Sr_{1-x}La_xTiO_3 and 0.92<k_{BR}<1 for YBCO. High-Tc superconductivity for YBCO is attributed to the true effective mass caused by the large k_{BR} value. The effective mass explains the metal-insulator transition of the first order on band filling. Furthermore, the pseudogap is predicted in this system.Comment: RevTex, 5 Pages, 1 figure.ep

High-TcT_c mechanism through analysis of diverging effective mass for YaBa2_2Cu3_3O6+x_{6+x} and pairing symmetry in cuprate superconductors

In order to clarify the high-$T_c$ mechanism in inhomogeneous cuprate layer superconductors, we deduce and find the correlation strength not revealed before, contributing to the formation of the Cooper pair and the 2-D density of state, and demonstrate the pairing symmetry in the superconductors still controversial. To the open questions, the fitting and analysis of the diverging effective mass with decreasing doping, extracted from the acquired quantum-oscillation data in underdoped YBCOO$_{6+x}$ superconductors, can provide solutions. Here, the results of the fitting using the extended Brinkman-Rice(BR) picture reveal the nodal constant Fermi energy with the maximum carrier density, a constant Coulomb correlation strength $k_{BR}$=$U/U_c$>0.90, and a growing Fermi arc from the nodal Fermi point to the isotropic Fermi surface with an increasing $x$. The growing of the Fermi arc indicates that a superconducting gap develops with $x$ from the node to the anti-node. The large $k_{BR}$ results from the $d$-wave MIT for the pseudogap phase in lightly doped superconductors, which can be direct evidence for high-$T_c$ superconductivity. The quantum critical point is regarded as the nodal Fermi point satisfied with the BR picture. The experimentally-measured mass diverging behavior is an average effect and the true effective mass is constant. As an application of the nodal constant carrier density, to find a superconducting node gap, the ARPES data and tunneling data are analyzed. The superconducting node gap is a precursor of $s$-wave symmetry in underdoped cuprates. The half-flux quantum, induced by the circulation of $d$-wave supercurrent and observed by the phase sensitive Josephson-pi junction experiments, is not shown due to anisotropic or asymmetric effect appearing in superconductors with trapped flux. The absence of $d$-wave superconducting pairing symmetry is also revealed.Comment: 19 pages, 21 figure

Extended Brinkman-Rice Picture and Its Application to High-Tc Superconductors

This is a full-paper of the paper(Physica C341-348, 259(2000)) published previously. The effective charge and the Coulomb energy are justified by means of measurement. Theoretical calculations of the effective mass depending on band filling are also given by Gutzwiller's variational calculations. On the basis of the concept of measurement, the effective mass is an average of the true effective mass in the Brinkman-Rice(BR) picture for metal phase and is the effect of measurement. The true correlation strength (U/U_c=k_{BR}) in the BR picture is evaluated as 0.92<k_{BR}<1 for YBCO. High-Tc superconductivity is attributed to the true effective mass caused by the large k_{BR} value. Furthermore, the validity of the BR picture is indirectly proved through the extended BR picture.Comment: Latex, 17pages, 3figure

Data Interpolations in Deep Generative Models under Non-Simply-Connected Manifold Topology

Exploiting the deep generative model's remarkable ability of learning the data-manifold structure, some recent researches proposed a geometric data interpolation method based on the geodesic curves on the learned data-manifold. However, this interpolation method often gives poor results due to a topological difference between the model and the dataset. The model defines a family of simply-connected manifolds, whereas the dataset generally contains disconnected regions or holes that make them non-simply-connected. To compensate this difference, we propose a novel density regularizer that make the interpolation path circumvent the holes denoted by low probability density. We confirm that our method gives consistently better interpolation results from the experiments with real-world image datasets.Comment: In AAAI-19 Workshop on Network Interpretability for Deep Learnin

Visual Explanations from Hadamard Product in Multimodal Deep Networks

The visual explanation of learned representation of models helps to understand the fundamentals of learning. The attentional models of previous works used to visualize the attended regions over an image or text using their learned weights to confirm their intended mechanism. Kim et al. (2016) show that the Hadamard product in multimodal deep networks, which is well-known for the joint function of visual question answering tasks, implicitly performs an attentional mechanism for visual inputs. In this work, we extend their work to show that the Hadamard product in multimodal deep networks performs not only for visual inputs but also for textual inputs simultaneously using the proposed gradient-based visualization technique. The attentional effect of Hadamard product is visualized for both visual and textual inputs by analyzing the two inputs and an output of the Hadamard product with the proposed method and compared with learned attentional weights of a visual question answering model.Comment: 8 pages, 5 figures, including appendix, NIPS 2017 Workshop on Visually-Grounded Interaction and Language (ViGIL

Temperature Dependence of Optical Spectra for the CDW Gap and Optical Phonons in BaBiO_3

We have studied the temperature dependence of the optical spectra for the CDW gap and optical phonons in a single crystal of BaBiO_3 and a film deposited by laser ablation. The integrated optical conductivity for optical phonons decreases rapidly with increasing temperature above 150 K, while the single-particle excitation across the CDW gap remains constant.Comment: 3 pages, 5 figures, ISS'9

Quantum Zeno Effect in Quantum Chaotic Systems

We analyzed the effect of frequent measurements on the quantum systems that are chaotic in the classical limit. It is shown that the kicked rotator, a well-known example of quantum chaos, is too special to be used as a testing ground for the effects of the repeated measurements. The abrupt change of state vectors by the delta-kick singular interruptions causes a quantum anti-Zeno effect. However, in more realistic systems with interaction potentials of continuous time dependence the quantum Zeno effect prevails.Comment: 5 pages, 4 figures, submitted to Phys. Rev.

Who Killed My Parked Car?

We find that the conventional belief of vehicle cyber attacks and their defenses---attacks are feasible and thus defenses are required only when the vehicle's ignition is turned on---does not hold. We verify this fact by discovering and applying two new practical and important attacks: battery-drain and Denial-of-Body-control (DoB). The former can drain the vehicle battery while the latter can prevent the owner from starting or even opening/entering his car, when either or both attacks are mounted with the ignition off. We first analyze how operation (e.g., normal, sleep, listen) modes of ECUs are defined in various in-vehicle network standards and how they are implemented in the real world. From this analysis, we discover that an adversary can exploit the wakeup function of in-vehicle networks---which was originally designed for enhanced user experience/convenience (e.g., remote diagnosis, remote temperature control)---as an attack vector. Ironically, a core battery-saving feature in in-vehicle networks makes it easier for an attacker to wake up ECUs and, therefore, mount and succeed in battery-drain and/or DoB attacks. Via extensive experimental evaluations on various real vehicles, we show that by mounting the battery-drain attack, the adversary can increase the average battery consumption by at least 12.57x, drain the car battery within a few hours or days, and therefore immobilize/cripple the vehicle. We also demonstrate the proposed DoB attack on a real vehicle, showing that the attacker can cut off communications between the vehicle and the driver's key fob by indefinitely shutting down an ECU, thus making the driver unable to start and/or even enter the car

Dual topological nodal line and nonsymmorphic Dirac semimetal in three dimensions

Previously known three-dimensional Dirac semimetals (DSs) occur in two types -- topological DSs and nonsymmorphic DSs. Here we present a novel three-dimensional DS that exhibits both features of the topological and nonsymmorphic DSs. We introduce a minimal tight-binding model for the space group 100 that describes a layered crystal made of two-dimensional planes in the $p4g$ wallpaper group. Using this model, we demonstrate that double glide-mirrors allow a noncentrosymmetric three-dimensional DS that hosts both symmetry-enforced Dirac points at time-reversal invariant momenta and twofold-degenerate Weyl nodal lines on a glide-mirror-invariant plane in momentum space. The proposed DS allows for rich topological physics manifested in both topological surface states and topological phase diagrams, which we discuss in detail. We also perform first-principles calculations to predict that the proposed DS is realized in a set of existing materials BaLa$X$B$Y_5$, where $X$ = Cu or Au, and $Y$ = O, S, or Se

Multimodal Dual Attention Memory for Video Story Question Answering

We propose a video story question-answering (QA) architecture, Multimodal Dual Attention Memory (MDAM). The key idea is to use a dual attention mechanism with late fusion. MDAM uses self-attention to learn the latent concepts in scene frames and captions. Given a question, MDAM uses the second attention over these latent concepts. Multimodal fusion is performed after the dual attention processes (late fusion). Using this processing pipeline, MDAM learns to infer a high-level vision-language joint representation from an abstraction of the full video content. We evaluate MDAM on PororoQA and MovieQA datasets which have large-scale QA annotations on cartoon videos and movies, respectively. For both datasets, MDAM achieves new state-of-the-art results with significant margins compared to the runner-up models. We confirm the best performance of the dual attention mechanism combined with late fusion by ablation studies. We also perform qualitative analysis by visualizing the inference mechanisms of MDAM.Comment: Accepted for ECCV 201