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We present an approach to simulating quantum computation based on a classical model that directly imitates discrete quantum systems. Qubits are represented as harmonic functions in a 2D vector space. Multiplication of qubit representations…

Quantum Physics · Physics 2009-06-30 Steven Peil

The theory relevant to the study of matter in equilibrium with the radiation field is thermal quantum electrodynamics (TQED). We present a formulation of the theory, suitable for non relativistic fluids, based on a joint functional integral…

Quantum Physics · Physics 2009-11-13 Pascal R. Buenzli , Philippe A. Martin , Marc D. Ryser

We employ Non-equilibrium Green's functions (NEGF) to describe the real-time dynamics of an adsorbate-surface model system exposed to ultrafast laser pulses. For a finite number of electronic orbitals, the system is solved exactly and…

Mesoscale and Nanoscale Physics · Physics 2016-05-04 E. Boström , M. Hopjan , A. Kartsev , C. Verdozzi , C. -O. Almbladh

Quantum simulation methods based on density-functional theory are currently deemed unfit to cope with atomic heat transport within the Green-Kubo formalism, because quantum-mechanical energy densities and currents are inherently ill-defined…

Materials Science · Physics 2016-01-20 Aris Marcolongo , Paolo Umari , Stefano Baroni

Quantum diffusion is studied via dissipative Madelung hydrodynamics. Initially the wave packet spreads ballistically, than passes for an instant through normal diffusion and later tends asymptotically to a sub-diffusive law. It is shown…

Quantum Physics · Physics 2011-04-21 Roumen Tsekov

In this paper we make attempt to obtain a description of the Quantum Hall Effect (both integer and fractional) by means of electron's Green functions of three-dimensional (planar) electrodynamics. We show that expression for the free…

Strongly Correlated Electrons · Physics 2007-05-23 Podist A. Kurashvili

We consider quantum decoherence in solid-state systems by studying the transverse dynamics of a single qubit interacting with a fermionic bath and driven by external pulses. Our interest is in investigating the extent to which the lost…

Mesoscale and Nanoscale Physics · Physics 2008-07-10 R. M. Lutchyn , L. Cywinski , Cody P. Nave , S. Das Sarma

Numerical modeling of radio-frequency waves in plasma with sufficiently high spatial and temporal resolution remains challenging even with modern computers. However, such simulations can be sped up using quantum computers in the future.…

Plasma Physics · Physics 2022-06-27 I. Novikau , E. A. Startsev , I. Y. Dodin

Potential non-relativistic Quantum Electrodynamics and the Keldysh-Schwinger formalism is used to derive Kadanoff-Baym-like equations for two-body field correlators. These cover the out-off-equilibrium dynamics and spectrum of heavy…

High Energy Physics - Theory · Physics 2021-10-13 Tobias Binder

The advent of hybrid computing platforms consisting of quantum processing units integrated with conventional high-performance computing brings new opportunities for algorithm design. By strategically offloading select portions of the…

This work presents a selective review of results concerning the mathematical interface between the classical and quantum aspects encountered in problems such as the nuclear mean-field dynamics or quantum Brownian motion. It is shown that…

Quantum Physics · Physics 2018-01-09 M. Grigorescu

The simulation of quantum transport in a realistic, many-particle system is a nontrivial problem with no quantitatively satisfactory solution. While real-time propagation has the potential to overcome the shortcomings of conventional…

Mesoscale and Nanoscale Physics · Physics 2015-10-16 Justin E. Elenewski , Yanxiang Zhao , Hanning Chen

Quantum Key Distribution has become a mature quantum technology that has outgrown dedicated links and is ready to be incorporated into the classical infrastructure. In this scenario with multiple potential nodes, it is crucial having…

Quantum Physics · Physics 2024-02-20 Lidia Ruiz , Juan Carlos Garcia-Escartin

In a previous paper, a project of constructing quantum models of classical properties has been started. The present paper concludes the project by turning to classical mechanics. The quantum states that maximize entropy for given averages…

Quantum Physics · Physics 2015-05-13 P. Hajicek

The objective of this paper is to describe a simple phenomenological approach for including incoherent dephasing processes in quantum transport models. The presented illustrative numerical results show this model provides the flexibility of…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Roksana Golizadeh-Mojarad , Supriyo Datta

We explore how the fundamental problems in quantum molecular dynamics can be modelled using classical simulators (emulators) of quantum computers and the actual quantum hardware available to us today. The list of problems we tackle includes…

Quantum Physics · Physics 2025-07-29 Tamila Kuanysheva , Brian Kendrick , Lukasz Cincio , Dmitri Babikov

Owing to the computational complexity of electronic structure algorithms running on classical digital computers, the range of molecular systems amenable to simulation remains tightly circumscribed even after many decades of work. Quantum…

Quantum Physics · Physics 2022-05-18 Alexis Ralli , Michael I. Williams , Peter V. Coveney

Using the nonequilibrium Green's function (NEGF) formalism, we propose a microscopic theory for near-field radiative heat transfer between metal plates. Tight-binding models for the electrons are coupled to the electromagnetic field…

Mesoscale and Nanoscale Physics · Physics 2016-07-12 Jian-Sheng Wang , Jiebin Peng

Can quantum computers effectively simulate the propagation and scattering of electromagnetic waves in a classical plasma? This chapter introduces some of the basic concepts in mathematics and physics essential to answering that question.…

Quantum Physics · Physics 2026-04-30 Abhay K. Ram , Efstratios Koukoutsis , George Vahala , Kyriakos Hizanidis

We present a generalized approach for computing electron conductance and I-V characteristics in multiterminal junctions from first-principles. Within the framework of Keldysh theory, electron transmission is evaluated employing an O(N)…

Materials Science · Physics 2015-05-13 Kamal K. Saha , Wenchang Lu , J. Bernholc , Vincent Meunier