English
Related papers

Related papers: Measuring the Density Matrix by Local Addressing

200 papers

Traditional antenna pattern measurements involve minimizing the impact of multipath propagation in the measurement environment. In contrast, this work introduces a measurement approach that uses rather than mitigates multipath propagation.…

Signal Processing · Electrical Eng. & Systems 2025-07-08 Daniel D. Stancil

Density ratio estimation in high dimensions can be reframed as integrating a certain quantity, the time score, over probability paths which interpolate between the two densities. In practice, the time score has to be estimated based on…

Machine Learning · Computer Science 2025-06-13 Hanlin Yu , Arto Klami , Aapo Hyvärinen , Anna Korba , Omar Chehab

We propose a method to probe the local density of states (LDOS) of atomic systems that provides both spatial and energy resolution. The method combines atomic and tunneling techniques to supply a simple, yet quantitative and operational,…

Mesoscale and Nanoscale Physics · Physics 2018-11-22 Daniel Gruss , Chih-Chun Chien , Julio Barreiro , Massimiliano Di Ventra , Michael Zwolak

We propose and investigate a procedure to measure, at least in principle, a positive quantum version of the local kinetic energy density. This procedure is based, under certain idealized limits, on the detection rate of photons emitted by…

Quantum Physics · Physics 2009-11-11 J. G. Muga , D. Seidel , G. C. Hegerfeldt

To quantify the effect of decoherence in quantum measurements, it is desirable to measure not merely the square modulus of the spatial wavefunction, but the entire density matrix, whose phases carry information about momentum and how pure…

Quantum Physics · Physics 2009-10-30 Max Tegmark

The density matrix renormalization group (DMRG) method is applied to the interaction round a face (IRF) model. When the transfer matrix is asymmetric, singular-value decomposition of the density matrix is required. A trial numerical…

Condensed Matter · Physics 2009-10-28 Tomotoshi Nishino

This article provides the first mathematical analysis of the Density Matrix Embedding Theory (DMET) method. We prove that, under certain assumptions, (i) the exact ground-state density matrix is a fixed-point of the DMET map for…

Mathematical Physics · Physics 2023-10-03 Eric Cancès , Fabian M. Faulstich , Alfred Kirsch , Eloïse Letournel , Antoine Levitt

Deep metric learning algorithms have been utilized to learn discriminative and generalizable models which are effective for classifying unseen classes. In this paper, a novel noise tolerant deep metric learning algorithm is proposed. The…

Machine Learning · Computer Science 2019-04-09 Soumyadeep Ghosh , Richa Singh , Mayank Vatsa

In this paper, we aim at tackling the problem of crowd counting in extremely high-density scenes, which contain hundreds, or even thousands of people. We begin by a comprehensive analysis of the most widely used density map-based methods,…

Computer Vision and Pattern Recognition · Computer Science 2018-01-23 Hanhui Li , Xiangjian He , Hefeng Wu , Saeed Amirgholipour Kasmani , Ruomei Wang , Xiaonan Luo , Liang Lin

In high-density crowds, local motion can propagate, amplify, and lead to macroscopic phenomena, including 'density waves'. These density waves only occur when individuals interact, and impulses are transferred to neighbours. How this…

Physics and Society · Physics 2024-03-01 Sina Feldmann , Thomas Chatagnon , Juliane Adrian , Julien Pettré , Armin Seyfried

In this paper I show that any $m$th-degree polynomial function of the elements of the density matrix $\rho$ can be determined by finding the expectation value of an observable on $m$ copies of $\rho$, without performing state tomography.…

Quantum Physics · Physics 2007-05-23 Todd A. Brun

We present a new method for determining the local dark matter density using kinematic data for a population of tracer stars. The Jeans equation in the $z$-direction is integrated to yield an equation that gives the velocity dispersion as a…

Astrophysics of Galaxies · Physics 2016-05-10 Hamish Silverwood , Sofia Sivertsson , Pascal Steger , Justin I. Read , Gianfranco Bertone

Discrete flow mapping was recently introduced as an efficient ray based method determining wave energy distributions in complex built up structures. Wave energy densities are transported along ray trajectories through polygonal mesh…

Computational Physics · Physics 2016-12-21 Janis Bajars , David Chappell , Niels Sondergaard , Gregor Tanner

The combination of deep learning and ab initio materials calculations is emerging as a trending frontier of materials science research, with deep-learning density functional theory (DFT) electronic structure being particularly promising. In…

Stimulated Raman Adiabatic Passage (STIRAP) and its variants, such as multi-state chainwise-STIRAP allow efficiently transferring the populations in multi-state system and have been widely used to prepare ultracold deeply-bound molecules.…

Quantum Physics · Physics 2024-07-30 Jiahui Zhang

The knowledge of the local electronic structure of heterogeneous solid materials is crucial for understanding their electronic, magnetic, transport, optical, and other properties. VASP, one of the mostly used packages for density-functional…

Materials Science · Physics 2022-05-18 Lucas Lodeiro , Tomáš Rauch

Combining multi-spectral satellite data and machine learning has been suggested as a method for monitoring plastic pollutants in the ocean environment. Recent studies have made theoretical progress regarding the identification of marine…

Image and Video Processing · Electrical Eng. & Systems 2023-05-03 Henry Booth , Wanli Ma , Oktay Karakus

Irregularly sampled AR(1) processes appear in many computationally demanding applications. This text provides an analytical expression for the precision matrix of such a process, and gives efficient algorithms for density evaluation and…

Methodology · Statistics 2018-05-30 Benjamin Allévius

We report on a far above saturation absorption imaging technique to investigate the characteristics of dense packets of ultracold atoms. The transparency of the cloud is controlled by the incident light intensity as a result of the…

Optics · Physics 2009-11-13 G. Reinaudi , T. Lahaye , Z. Wang , D. Guery-Odelin

We propose a systematic procedure for the approximation of density functionals in density functional theory that consists of two parts. First, for the efficient approximation of a general density functional, we introduce an efficient ansatz…

Strongly Correlated Electrons · Physics 2016-08-29 Michael Lubasch , Johanna I. Fuks , Heiko Appel , Angel Rubio , J. Ignacio Cirac , Mari-Carmen Bañuls
‹ Prev 1 8 9 10 Next ›