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Related papers: A Time-Dependent Random State Approach for Large-s…

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To simulate thermalizing systems at long times, the most straightforward approach is to calculate the thermal properties at the corresponding energy. In a quantum many-body system of size $N$, for local observables and many initial states,…

Statistical Mechanics · Physics 2024-06-11 Yichen Huang

Time-dependent density functional theory (TDDFT) is rapidly emerging as a premier method for solving dynamical many-body problems in physics and chemistry. The mathematical foundations of TDDFT are established through the formal existence…

Quantum Physics · Physics 2014-08-22 J. D. Whitfield , M. -H. Yung , D. G. Tempel , S. Boixo , A. Aspuru-Guzik

We present a universal technique for quantum state estimation based on the maximum-likelihood method. This approach provides a positive definite estimate for the density matrix from a sequence of measurements performed on identically…

Quantum Physics · Physics 2009-10-31 K. Banaszek , G. M. D'Ariano , M. G. A. Paris , M. F. Sacchi

Time-dependent orbital-free DFT is an efficient method for calculating the dynamic properties of large scale quantum systems due to the low computational cost compared to standard time-dependent DFT. We formalize this method by mapping the…

Chemical Physics · Physics 2021-06-09 Kaili Jiang , Michele Pavanello

One of the potential applications of a quantum computer is solving quantum chemical systems. It is known that one of the fastest ways to obtain somewhat accurate solutions classically is to use approximations of density functional theory.…

Quantum Physics · Physics 2020-11-18 Thomas E. Baker , David Poulin

Reliable and robust convergence to the electronic ground state within density functional theory (DFT) Kohn-Sham (KS) calculations remains a thorny issue in many systems of interest. In such cases, charge sloshing can delay or completely…

Computational Physics · Physics 2020-04-07 Cedric Flamant , Grigory Kolesov , Efstratios Manousakis , Efthimios Kaxiras

The Liouville-Lanczos approach to linear-response time-dependent density-functional theory is generalized so as to encompass electron energy-loss and inelastic X-ray scattering spectroscopies in periodic solids. The computation of virtual…

Materials Science · Physics 2015-06-16 Iurii Timrov , Nathalie Vast , Ralph Gebauer , Stefano Baroni

We establish a large deviation principle for time dependent trajectories (paths) of the empirical density of $N$ particles with long range interactions, for homogeneous systems. This result extends the classical kinetic theory that leads to…

Statistical Mechanics · Physics 2022-01-19 Ouassim Feliachi , Freddy Bouchet

This paper gives an introduction to the Keldysh formalism, with emphasis on its usefulness in time-dependent density functional theory. In the first part we introduce the Keldysh contour and the one-particle Green function defined on this…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Robert van Leeuwen , Nils Erik Dahlen , Gianluca Stefanucci , Carl-Olof Almbladh , Ulf von Barth

Starting from an independent-particle model with a finite and arbitrary set of single-particle energies, we develop an analytical approximation to the many-body level density $\rho_A(E)$ and to particle-hole densities. We use exact…

Nuclear Theory · Physics 2013-09-30 Adriana Pálffy , Hans A. Weidenmüller

We derive a self-consistent local variant of the Thomas-Fermi approximation for (quasi-)two-dimensional (2D) systems by localizing the Hartree term. The scheme results in an explicit orbital-free representation of the electron density and…

Strongly Correlated Electrons · Physics 2013-02-04 E. Rasanen , S. Pittalis , G. Bekcioglu , I. Makkonen

The frequency dependent conductance of a two-dimensional quantum wire is computed using a current conserving formalism. The correction to the dc-conductance due to a time-dependent potential is related to the local partial density of states…

Condensed Matter · Physics 2009-10-28 Jian Wang , Hong Guo

A new method to calculate level densities for non-interacting Fermions within the constant-spacing model with a finite number of states is developed. We show that asymptotically (for large numbers of particles or holes) the densities have…

Nuclear Theory · Physics 2013-01-08 Adriana Pálffy , Hans A. Weidenmüller

We develop a theory for a generic instability of a Fermi liquid in dimension d>1 against the formation of a Luttinger-liquid-like state. The density of states at the Fermi level is the order parameter for the ensuing quantum phase…

Strongly Correlated Electrons · Physics 2013-10-01 T. R. Kirkpatrick , D. Belitz

Relativistic mean field theory is formulated with the Green's function method in coordinate space to investigate the single-particle bound states and resonant states on the same footing. Taking the density of states for free particle as a…

Nuclear Theory · Physics 2015-06-23 T. T. Sun , S. Q. Zhang , Y. Zhang , J. N. Hu , J. Meng

In order to obtain a reasonably accurate and easily implemented approach to many-electron calculations, we will develop a new Density Functional Theory (DFT). Specifically, we derive an approximation to electron density, the first term of…

Materials Science · Physics 2010-04-23 Gregory C. Dente

The nuclear energy density functional method at finite temperature is a useful tool for studies of nuclear structure at high excitation, and also for researches of nuclear matter involved in explosive stellar phenomena and neutron stars.…

Nuclear Theory · Physics 2023-03-02 Takashi Nakatsukasa

We investigate the time an electronic excitation travels in a supermolecular setup using a measurement process in an open quantum-system framework. The approach is based on the stochastic Schr\"odinger equation and uses a Hamiltonian from…

Materials Science · Physics 2013-12-09 Dirk Hofmann , Heiko Appel , Massimiliano Di Ventra , Stephan Kümmel

The self consistent version of the density functional theory is presented, which allows to calculate the ground state and dynamic properties of finite multi-electron systems. An exact functional equation for the effective interaction, from…

Materials Science · Physics 2017-08-23 M. Ya. Amusia , A. Z. Msezane , V. R. Shaginyan

The density of states of continuous models is known to span many orders of magnitudes at different energies due to the small volume of phase space near the ground state. Consequently, the traditional Wang-Landau sampling which uses the same…

Statistical Mechanics · Physics 2013-11-20 Yang Wei Koh , Hwee Kuan Lee , Yutaka Okabe
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