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Related papers: Prony methods for extracting excited states

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We show that our procedure of constructing excited-state energy functionals by splitting k-space, employed so far to obtain exchange energies of excited-states, is quite general. We do so by applying the same method to construct modified…

Atomic and Molecular Clusters · Physics 2010-02-17 M. Hemanadhan , Manoj K. Harbola

Accurate phase estimation in the presence of unknown phase diffusive noise is a crucial yet challenging task in noisy quantum metrology. This problem is particularly interesting due to the detrimental impact of the associated noise. Here,…

Quantum Physics · Physics 2024-07-12 Jayanth Jayakumar , Monika E. Mycroft , Marco Barbieri , Magdalena Stobińska

We consider excited vortex states, which are vortex states left inside a superconductor once the external applied magnetic field is switched off and whose energy is lower than of the normal state. We show that this state is paramagnetic and…

Superconductivity · Physics 2016-07-20 Rodolpho Ribeiro Gomes , Mauro M. Doria , Antonio R. de C. Romaguera

We show that, in certain circumstances, exact excitation energies appear as locally site-independent (or flat) modes if one records the excitation spectrum of the effective Hamiltonian while sweeping through the lattice in the variational…

Strongly Correlated Electrons · Physics 2017-08-24 Natalia Chepiga , Frédéric Mila

Jarzynski's equality provides an elegant and powerful tool to directly compute differences in free energy in Monte Carlo simulations and it can be readily extended to lattice gauge theories to compute a large set of physically interesting…

High Energy Physics - Lattice · Physics 2018-04-18 Alessandro Nada , Michele Caselle , Marco Panero

In this paper we consider excited state g-functions, that is, overlaps between boundary states and excited states in boundary conformal field theory. We find a new method to calculate these overlaps numerically using a variation of the…

High Energy Physics - Theory · Physics 2015-06-03 Gabor Takacs , Gerard Watts

A set of density functionals coming from different rungs on Jacob's ladder are employed to evaluate the electronic excited states of three Ru(II) complexes. While most studies on the performance of density functionals compare the vertical…

In this paper, we consider the problem of state estimation through observations possibly corrupted with both bad data and additive observation noises. A mixed $\ell_1$ and $\ell_2$ convex programming is used to separate both sparse bad data…

Information Theory · Computer Science 2011-05-04 Weiyu Xu , Meng Wang , Ao Tang

Early work extending the Kohn-Sham theory to excited states utilized an ensemble average of the Hamiltonian considered as a functional of the corresponding average density. We propose and develop an alternative that utilizes the matrix…

Atomic Physics · Physics 2007-05-23 Abraham Klein , Reiner M. Dreizler

Several approximations are tested by calculating the ground-state energy and the energy of the first excited $0^{+}$ state using an exactly solvable model with two symmetric levels interacting via a pairing force. They are the BCS…

Nuclear Theory · Physics 2009-09-29 Nguyen Dinh Dang

Monte Carlo techniques with importance sampling have been extensively applied to lattice gauge theory in the Lagrangian formulation. Unfortunately, it is extremely difficult to compute the excited states using the conventional Monte Carlo…

High Energy Physics - Lattice · Physics 2017-08-23 Xiang-Qian Luo , H. Jirari , H. Kroger , K. Moriarty

In this study, a method for quantum state readout and feature extraction is developed using quantum overlap-based fitting of function expansions. The approach involves the quantum calculation of quantum overlaps between a target quantum…

Excited-state properties of highly correlated systems are key to understanding photosynthesis, luminescence, and the development of novel optical materials, but accurately capturing their interactions is computationally costly. We present…

Quantum Physics · Physics 2024-08-21 Irma Avdic , David A. Mazziotti

In this talk we discuss a novel method, that we have presented in Ref. [1], to extract hadronic spectral densities from lattice correlators by using deep learning techniques. Hadronic spectral densities play a crucial role in the study of…

High Energy Physics - Lattice · Physics 2024-01-12 Michele Buzzicotti , Alessandro De Santis , Nazario Tantalo

Lattice QCD has matured to a degree where it is now possible to study excited hadrons as they truly appear in nature, as short-lived resonant enhancements decaying into multiple possible final states. Through variational analysis of…

High Energy Physics - Lattice · Physics 2018-09-21 Jozef J. Dudek

Recent work found that an analysis formalism based on the Lanczos algorithm allows energy levels to be extracted from Euclidean correlation functions with faster ground-state convergence than effective masses, convergent estimators for…

High Energy Physics - Lattice · Physics 2025-09-12 Daniel C. Hackett , Michael L. Wagman

Based on the MPS formalism, we introduce an ansatz for capturing excited states in finite systems with open boundary conditions, providing a very efficient method for computing, e.g., the spectral gap of quantum spin chains. This method can…

Strongly Correlated Electrons · Physics 2022-06-09 Maarten Van Damme , Robijn Vanhove , Jutho Haegeman , Frank Verstraete , Laurens Vanderstraeten

Employing the maximum entropy method we extract the spectral functions from meson correlators at four lattice spacings in quenched QCD with the Wilson quark action. We confirm that the masses and decay constants, obtained from the position…

We propose an improvement of the differential method for the computation of the equation of state of QCD from lattice simulations. In contrast to the earlier differential method our technique yields positive pressure for all temperatures…

High Energy Physics - Lattice · Physics 2015-06-25 Rajiv V. Gavai , Sourendu Gupta , Swagato Mukherjee

We have developed a simple algorithm for defining a single proxy state which accounts for state truncation in the sum-over-states calculations of the dispersion of the molecular hyperpolarizabilities. The transition strengths between the…

Optics · Physics 2018-12-26 Sean Mossman , Mark G. Kuzyk