English
Related papers

Related papers: Quantum kinetic energy densities: An operational a…

200 papers

This paper describes a simple, causally deterministic model of quantum measurement based on an amplitude threshold detection scheme. Surprisingly, it is found to reproduce many phenomena normally thought to be uniquely quantum in nature. To…

Quantum Physics · Physics 2021-04-28 Brian R. La Cour

A quantum electrodynamical time-dependent density functional theory framework is applied to describe strongly coupled light--matter interactions in cavity environments. The formalism utilizes a tensor product approach, coupling real-space…

Chemical Physics · Physics 2025-11-27 Yetmgeta Aklilu , Matthew Shepherd , Cody L. Covington , Kalman Varga

A satisfactory theory of quantum gravity may necessitate a drastic modification of our perception of space-time, by giving it a foamy structure at distances comparable to the Planck length. It is argued in this essay that the experimental…

General Relativity and Quantum Cosmology · Physics 2009-09-11 John. Ellis , N. E. Mavromatos , D. V. Nanopoulos

Proximity measurements probe whether pairs of particles are close to one another. We consider the impact of post-selected random proximity measurements on a quantum fluid of many distinguishable particles. We show that such measurements…

Quantum Physics · Physics 2025-08-01 Pushkar Mohile , Paul M. Goldbart

An analysis of errors in measurement yields new insight into the penetration of quantum particles into classically forbidden regions. In addition to ``physical" values, realistic measurements yield ``unphysical" values which, we show, can…

High Energy Physics - Theory · Physics 2009-10-22 Y. Aharonov , S. Popescu , D. Rohrlich , L. Vaidman

Quantum control of atoms at ultrashort distances from surfaces would open a new paradigm in quantum optics and offer a novel tool for the investigation of near-surface physics. Here, we investigate the motional states of atoms that are…

Quantum Physics · Physics 2021-04-23 Daniel Hümmer , Oriol Romero-Isart , Arno Rauschenbeutel , Philipp Schneeweiss

A Hamiltonian based approach using spatially localized projection operators is introduced to give precise meaning to the chemically intuitive idea of the electronic energy on a quantum subsystem. This definition facilitates the study of…

Quantum Physics · Physics 2015-06-11 Yaser R. Khan , Paul Brumer

Quantum molecular dynamics is applied to study the ground state properties of nuclear matter at subsaturation densities. Clustering effects are observed as to soften the equation of state at these densities. The structure of nuclear matter…

We propose and analyze a scanning microscope to monitor `live' the quantum dynamics of cold atoms in a Cavity QED setup. The microscope measures the atomic density with subwavelength resolution via dispersive couplings to a cavity and…

Quantum Physics · Physics 2019-02-26 Dayou Yang , Catherine Laflamme , Denis Vasilyev , Mikhail Baranov , Peter Zoller

For theoretical approach of quantum measurements it is proposed a set of reconsidered conjectures. The proposed approach implies linear functional transformations for probability density and current but preserves the expressions for…

Quantum Physics · Physics 2007-05-23 S. Dumitru

We establish a physically meaningful representation of a quantum energy density for use in Quantum Monte Carlo calculations. The energy density operator, defined in terms of Hamiltonian components and density operators, returns the correct…

Materials Science · Physics 2013-08-09 Jaron T. Krogel , Min Yu , Jeongnim Kim , David M. Ceperley

Quantum correlations in a physical system are usually studied with respect to a unique (fixed) decomposition of the system into subsystems, without fully exploiting the rich structure of the state-space. Here, we show several examples in…

Quantum Physics · Physics 2016-07-20 Guido Bellomo , Angelo Plastino , Angel R. Plastino

I apply the scattering approach within the framework of macroscopic quantum electrodynamics to derive the variances and mean values of the energy density and intensity for a system of an arbitrary object in an arbitrary environment. To…

Mesoscale and Nanoscale Physics · Physics 2023-12-15 Florian Herz

In a two-dimensional approximation, the probability density and current for a photoelectron near the localization of a quantum vortex are theoretically investigated. The wave function in the momentum representation, which we found earlier,…

Quantum Physics · Physics 2024-02-08 N. V. Larionov , Yu. L. Kolesnikov

We describe in a qualitative way a possible picture of the Measurement Process in Quantum Mechanics, which takes into account: 1. the finite and non zero time duration T of the interaction between the observed system and the microscopic…

Quantum Physics · Physics 2018-02-20 Sergio Doplicher

Building on the "quantum inequalities" introduced by Ford, I argue that the negative local energies encountered in quantum field theory can only be observed by detectors with positive energies at least as great in magnitude. This means that…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Adam D. Helfer

The quantum random number generation based on laser phase noise, which is featured with high generation rate and ease for photonic integration, has been extensively investigated and demonstrated. Despite these advancements, a theoretical…

Quantum Physics · Physics 2026-04-17 Jinlu Liu , Jie Yang , Yu Gao , Guowei Zhang , Yan Pan , Heng Wang , Yuyang Ding , Yang Li , Wei Huang , Bingjie Xu , Wei Chen

Many-body localization, the persistence against electron-electron interactions of the localization of states with non-zero excitation energy density, poses a challenge to current methods of theoretical and numerical analysis. Numerical…

Disordered Systems and Neural Networks · Physics 2014-11-06 Bela Bauer , Chetan Nayak

Maximum likelihood estimation is one of the most used methods in quantum state tomography, where the aim is to reconstruct the density matrix of a physical system from measurement results. One strategy to deal with positivity and unit trace…

We introduce two methods for estimating the density matrix for a quantum system: Quantum Maximum Likelihood and Quantum Variational Inference. In these methods, we construct a variational family to model the density matrix of a mixed…

Quantum Physics · Physics 2019-04-15 Kyle Cranmer , Siavash Golkar , Duccio Pappadopulo