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Adaptive optics (AO) system performance is improved using post-processing techniques, such as point spread function (PSF) deconvolution. The PSF estimation involves characterization of the different wavefront (WF) error sources in the AO…

Instrumentation and Methods for Astrophysics · Physics 2018-08-29 Florian Ferreira , Eric Gendron , Gérard Rousset , Damien Gratadour

We introduce a novel solver to significantly reduce the size of a geometric operator while preserving its spectral properties at the lowest frequencies. We use chordal decomposition to formulate a convex optimization problem which allows…

Graphics · Computer Science 2020-09-16 Honglin Chen , Hsueh-Ti Derek Liu , Alec Jacobson , David I. W. Levin

First-principles phonon calculations have been widely performed for studying vibrational properties of condensed matter, where the dynamical matrix is commonly constructed via supercell force-constant calculations or the linear response…

Materials Science · Physics 2020-11-11 Chi-Cheng Lee , Chin-En Hsu , Hung-Chung Hsueh

A systematic computational study on the structural, electronic, bonding, and optical properties of orthorhombic ammonium azide (NH$_4$N$_3$) has been performed using planewave pseudopotential (PW-PP) method based on density functional…

Materials Science · Physics 2013-11-07 N. Yedukondalu , Vikas D. Ghule , G. Vaitheeswaran

We propose a sparse grids based adaptive noise reduction strategy for electrostatic particle-in-cell (PIC) simulations. Our approach is based on the key idea of relying on sparse grids instead of a regular grid in order to increase the…

We study the Complex Absorbing Potential (CAP) Method in computing quantum resonances of width $c(h) = O(h^N)$, $N\gg1$. We show that up to $h^{-M}\sqrt{c(h)} +\Oh$ error, $M\gg1$, resonances are perturbed eigenvalues of the CAP Hamiltonian…

Mathematical Physics · Physics 2007-05-23 Plamen Stefanov

We present a real-space method for computing the random phase approximation (RPA) correlation energy within Kohn-Sham density functional theory, leveraging the low-rank nature of the frequency-dependent density response operator. In…

Computational Physics · Physics 2025-04-03 Boqin Zhang , Shikhar Shah , John E. Pask , Edmond Chow , Phanish Suryanarayana

We develop the Fourier-Laplace Inversion of the Perturbation Theory (FLIPT), a novel numerically exact "black box" method to compute perturbative expansions of the density matrix with rigorous convergence conditions. Specifically, the FLIPT…

Chemical Physics · Physics 2020-04-21 Cyrille Lavigne , Paul Brumer

Using a super-operator formulation of linearized time-dependent density-functional theory, the dynamical polarizability of a system of interacting electrons is given a matrix continued-fraction representation whose coefficients can be…

Materials Science · Physics 2009-11-11 B. Walker , A. M. Saitta , R. Gebauer , S. Baroni

Path-integral approach to the tight-binding polaron is extended to multiple optical phonon modes of arbitrary dispersion and polarization. The non-linear lattice effects are neglected. Only one electron band is considered. The…

Strongly Correlated Electrons · Physics 2009-11-11 Pavel Kornilovitch

The electronic and vibrational properties and electron-phonon couplings of one-dimensional materials will be key to many prospective applications in nanotechnology. Dimensionality strongly affects these properties and has to be correctly…

Materials Science · Physics 2023-10-09 Norma Rivano , Nicola Marzari , Thibault Sohier

A linear scaling method for calculation of the static {\em ab inito} response within self-consistent field theory is developed and applied to calculation of the static electric polarizability. The method is based on density matrix…

Materials Science · Physics 2009-11-10 Valery Weber , Anders Niklasson , Matt Challacombe

We present a real-space adaptive-coordinate method, which combines the advantages of the finite-difference approach with the accuracy and flexibility of the adaptive coordinate method. The discretized Kohn-Sham equations are written in…

mtrl-th · Physics 2009-10-28 Francois Gygi , Giulia Galli

This article reviews the current status of lattice-dynamical calculations in crystals, using density-functional perturbation theory, with emphasis on the plane-wave pseudo-potential method. Several specialized topics are treated, including…

Materials Science · Physics 2009-10-31 S. Baroni , S. de Gironcoli , A. Dal Corso , P. Giannozzi

Deep-learning accelerators are increasingly in demand; however, their performance is constrained by the size of the feature map, leading to high bandwidth requirements and large buffer sizes. We propose an adaptive scale feature map…

Computer Vision and Pattern Recognition · Computer Science 2025-03-25 Yuan Yao , Tian-Sheuan Chang

We present an algorithm that extends existing quantum algorithms for simulating fermion systems in quantum chemistry and condensed matter physics to include bosons in general and phonons in particular. We introduce a qubit representation…

Quantum Physics · Physics 2020-10-30 Alexandru Macridin , Panagiotis Spentzouris , James Amundson , Roni Harnik

Unless special conditions apply, the attempt to solve ill-conditioned systems of linear equations with standard numerical methods leads to uncontrollably high numerical error. Often, such systems arise from the discretization of operator…

Numerical Analysis · Mathematics 2021-05-18 Stephan Mohr , Yuji Nakatsukasa , Carolina Urzúa-Torres

We propose a quantum simulation of small-polaron physics using a one-dimensional system of trapped ions acted upon by off-resonant standing waves. This system, envisioned as an array of microtraps, in the single-excitation case allows the…

Quantum Gases · Physics 2012-12-18 Vladimir M. Stojanovic , Tao Shi , C. Bruder , J. Ignacio Cirac

Nonradiative carrier recombination at semiconductor deep centers is of great importance to both fundamental physics and device engineering. In this letter, we provide a revised analysis of K. Huang's original nonradiative multi-phonon (NMP)…

Materials Science · Physics 2020-01-01 Yao Xiao , Zi-Wu Wang , Lin Shi , Xiangwei Jiang , Shu-Shen Li , Lin-Wang Wang

We develop a stochastic formulation of the optimally-tuned range-separated hybrid density functional theory which enables significant reduction of the computational effort and scaling of the non-local exchange operator at the price of…

Chemical Physics · Physics 2016-09-28 Daniel Neuhauser , Eran Rabani , Yael Cytter , Roi Baer