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Related papers: Overcoming positivity violations for density matri…

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The stochastic density functional theory (DFT) [Phys. Rev. Lett. 111, 106402 (2013)] is a valuable linear scaling approach to Kohn-Sham DFT that does not rely on the sparsity of the density matrix. Linear (and often sub-linear) scaling is…

Chemical Physics · Physics 2019-02-20 Ming Chen , Roi Baer , Daniel Neuhauser , Eran Rabani

We study the dynamics of a macroscopic object interacting with a dissipative stochastic environment using an adiabatic perturbation theory. The perturbation theory reproduces known expressions for the friction coefficient and, surprisingly,…

Statistical Mechanics · Physics 2015-10-07 Luca D'Alessio , Yariv Kafri , Anatoli Polkovnikov

Coherent transport by adiabatic passage has recently been suggested as a high-fidelity technique to engineer the centre-of-mass state of single atoms in inhomogenous environments. While the basic theory behind this process is well…

Quantum Physics · Physics 2015-03-19 T. Morgan , B. O'Sullivan , Th. Busch

Positivity violations can complicate estimation and interpretation of causal dose-response curves (CDRCs) for continuous interventions. Weighting-based methods are designed to handle limited overlap, but the resulting weighted targets can…

Methodology · Statistics 2026-02-13 Han Bao , Michael Schomaker

Screened range-separated hybrid (SRSH) functionals within generalized Kohn-Sham density functional theory (GKS-DFT) have been shown to restore a general $1/(r\varepsilon)$ asymptotic decay of the electrostatic interaction in dielectric…

Computational Physics · Physics 2023-06-26 Tammo van der Heide , Bálint Aradi , Ben Hourahine , Thomas Frauenheim , Thomas A. Niehaus

We propose a scheme to prepare arbitrary superpositions of quantum states in double quantum--dots irradiated by coherent microwave pulses. Solving the equations of motion for the dot density matrix, we find that dephasing rates for such…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 T. Brandes , F. Renzoni , R. H. Blick

Coarse-grained (CG) conformational surface hopping (SH) adapts the concept of multisurface dynamics, initially developed to describe electronic transitions in chemical reactions, to accurately describe classical molecular dynamics at a…

Soft Condensed Matter · Physics 2021-02-03 Joseph F. Rudzinski , Tristan Bereau

We shall revisit the conventional adiabatic or Markov approximation, which --contrary to the semiclassical case-- does not preserve the positive-definite character of the corresponding density matrix, thus leading to highly non-physical…

Quantum Physics · Physics 2015-05-13 David Taj , Rita Claudia Iotti , Fausto Rossi

Recently, nonadiabatic geometric quantum computation has been received great attentions, due to its fast operation and intrinsic error resilience. However, compared with the corresponding dynamical gates, the robustness of implemented…

Quantum Physics · Physics 2023-07-12 Cheng-Yun Ding , Li Chen , Li-Hua Zhang , Zheng-Yuan Xue

An apporach for the sensing of small amounts of chemical and biochemical material is presented. A frequency selective surface (FSS) made from asymmetric split ring resonators (aDSR) is excited with free space radiation. Due to interference…

Applied Physics · Physics 2021-04-13 Christian Debus , Peter Haring Bolívar

The impact of coherence on the nonlinear optical response and stationary transport is studied in quantum cascade laser structures. Nonequilibrium effects such as pump-probe signals, the spatio-temporally resolved electron density evolution,…

Mesoscale and Nanoscale Physics · Physics 2009-05-12 C. Weber , A. Wacker , A. Knorr

In this paper, a new efficient and generalized consistency correction method for weakly-compressible smoothed particle hydrodynamics is proposed and successfully implemented in the simulation of violent free-surface flow exhibiting breaking…

Fluid Dynamics · Physics 2024-05-24 Yaru Ren , Pengzhi Lin , Chi Zhang , Xiangyu Hu

We reveal universal dynamical scaling behavior across adiabatic quantum phase transitions (QPTs) in networks ranging from traditional spatial systems (Ising model) to fully connected ones (Dicke and Lipkin-Meshkov-Glick models). Our…

Quantum Physics · Physics 2015-06-18 O. L. Acevedo , L. Quiroga , F. J. Rodríguez , N. F. Johnson

The problem of prediction in functional linear regression is conventionally addressed by reducing dimension via the standard principal component basis. In this paper we show that an alternative basis chosen through weighted least-squares,…

Methodology · Statistics 2009-02-20 Aurore Delaigle , Peter Hall , Tatiyana V. Apanasovich

Mixed states of a quantum system, represented by density operators, can be decomposed as a statistical mixture of pure states in a number of ways where each decomposition can be viewed as a different preparation recipe. However the fact…

Quantum Physics · Physics 2016-01-26 Sandeep K Goyal , Rajeev Singh , Sibasish Ghosh

Density-functional theory (DFT) has revolutionized computer simulations in chemistry and material science. A faithful implementation of the theory requires self-consistent calculations. However, this effort involves repeatedly diagonalizing…

Quantum Physics · Physics 2023-07-17 Taehee Ko , Xiantao Li , Chunhao Wang

Quantum annealers require accurate control and optimized operation schemes to reduce noise levels, in order to eventually demonstrate a computational advantage over classical algorithms. We study a high coherence four-junction capacitively…

For the prototypical example of the Ising chain in a transverse field, we study the impact of decoherence on the sweep through a second-order quantum phase transition. Apart from the advance in the general understanding of the dynamics of…

Quantum Physics · Physics 2007-09-17 Sarah Mostame , Gernot Schaller , Ralf Schützhold

We provide insight into the qubit measurement process involving a switching type of detector. We study the switching-induced decoherence during escape events. We present a simple method to obtain analytical results for the qubit dephasing…

Mesoscale and Nanoscale Physics · Physics 2009-05-20 I. Serban , F. K. Wilhelm

A simple model is considered for an open system consisting of an aggregation of magnetic particles (like greigite) in the presence of a magnetic field (H), and interacting linearly with a bath of 3D harmonic oscillators. Using the…

Mesoscale and Nanoscale Physics · Physics 2012-03-13 A. N. Mitra
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