Femtosecond time-resolved solvation process of a solution: Constraints of vibrational degrees of freedom in the supercooled state

2006 ◽  
Vol 417 (4-6) ◽  
pp. 550-554 ◽  
Author(s):  
Hiroshi Murakami
Keyword(s):  
Degrees Of Freedom ◽  
Time Resolved ◽  
Supercooled State

scholarly journals Probing the interplay between lattice dynamics and short-range magnetic correlations in CuGeO3 with femtosecond RIXS

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
E. Paris ◽  
C. W. Nicholson ◽  
S. Johnston ◽  
Y. Tseng ◽  
M. Rumo ◽  
...  
Keyword(s):  
Short Range ◽  
Degrees Of Freedom ◽  
Time Resolved ◽  
Model Calculations ◽  
Spin Correlations ◽  
Singlet Exciton ◽  
Magnetic Correlations ◽  
Local Lattice ◽  
Frustrated Systems ◽  
A Charge

AbstractInvestigations of magnetically ordered phases on the femtosecond timescale have provided significant insights into the influence of charge and lattice degrees of freedom on the magnetic sub-system. However, short-range magnetic correlations occurring in the absence of long-range order, for example in spin-frustrated systems, are inaccessible to many ultrafast techniques. Here, we show how time-resolved resonant inelastic X-ray scattering (trRIXS) is capable of probing such short-ranged magnetic dynamics in a charge-transfer insulator through the detection of a Zhang–Rice singlet exciton. Utilizing trRIXS measurements at the O K-edge, and in combination with model calculations, we probe the short-range spin correlations in the frustrated spin chain material CuGeO3 following photo-excitation, revealing a strong coupling between the local lattice and spin sub-systems.

scholarly journals Time-resolved observation of spin-charge deconfinement in fermionic Hubbard chains

Science ◽  
2020 ◽  
Vol 367 (6474) ◽  
pp. 186-189 ◽  
Author(s):  
Jayadev Vijayan ◽  
Pimonpan Sompet ◽  
Guillaume Salomon ◽  
Joannis Koepsell ◽  
Sarah Hirthe ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Spatial Separation ◽  
Real Space ◽  
Quantum Gas ◽  
Interacting Particles ◽  
Time Resolved ◽  
One Dimensional ◽  
Quantum Numbers ◽  
Charge Correlations ◽  
The Individual

Elementary particles carry several quantum numbers, such as charge and spin. However, in an ensemble of strongly interacting particles, the emerging degrees of freedom can fundamentally differ from those of the individual constituents. For example, one-dimensional systems are described by independent quasiparticles carrying either spin (spinon) or charge (holon). Here, we report on the dynamical deconfinement of spin and charge excitations in real space after the removal of a particle in Fermi-Hubbard chains of ultracold atoms. Using space- and time-resolved quantum gas microscopy, we tracked the evolution of the excitations through their signatures in spin and charge correlations. By evaluating multipoint correlators, we quantified the spatial separation of the excitations in the context of fractionalization into single spinons and holons at finite temperatures.

scholarly journals Learning the non-equilibrium dynamics of Brownian movies

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Federico S. Gnesotto ◽  
Grzegorz Gradziuk ◽  
Pierre Ronceray ◽  
Chase P. Broedersz
Keyword(s):  
Degrees Of Freedom ◽  
Time Lapse ◽  
Direct Access ◽  
Dynamical Analysis ◽  
Entropy Production Rate ◽  
Microscopy Imaging ◽  
Time Resolved ◽  
Equilibrium Dynamics ◽  
Many Body Systems ◽  
Non Equilibrium

Abstract Time-lapse microscopy imaging provides direct access to the dynamics of soft and living systems. At mesoscopic scales, such microscopy experiments reveal intrinsic thermal and non-equilibrium fluctuations. These fluctuations, together with measurement noise, pose a challenge for the dynamical analysis of these Brownian movies. Traditionally, methods to analyze such experimental data rely on tracking embedded or endogenous probes. However, it is in general unclear, especially in complex many-body systems, which degrees of freedom are the most informative about their non-equilibrium nature. Here, we introduce an alternative, tracking-free approach that overcomes these difficulties via an unsupervised analysis of the Brownian movie. We develop a dimensional reduction scheme selecting a basis of modes based on dissipation. Subsequently, we learn the non-equilibrium dynamics, thereby estimating the entropy production rate and time-resolved force maps. After benchmarking our method against a minimal model, we illustrate its broader applicability with an example inspired by active biopolymer gels.

Investigation of the flight behavior of a flare-stabilized projectile using 6DoF simulations coupled with CFD

2019 ◽  
Vol 30 (9) ◽  
pp. 4185-4201
Author(s):  
Daniel Klatt ◽  
Michael Proff ◽  
Robert Hruschka
Keyword(s):  
Degrees Of Freedom ◽  
Rigid Body Dynamics ◽  
Flight Behavior ◽  
Free Flight ◽  
Aerodynamic Coefficients ◽  
Cfd Simulations ◽  
Time Resolved ◽  
Content Type ◽  
Six Degrees Of Freedom ◽  
Computational Fluid Dynamics Cfd

Purpose The present work aims to investigate the capabilities of accurately predicting the six-degrees-of-freedom (6DoF) trajectory and the flight behavior of a flare-stabilized projectile using computational fluid dynamics (CFD) and rigid body dynamics (RBD) methods. Design/methodology/approach Two different approaches are compared for calculating the trajectory. First, the complete matrix of static and dynamic aerodynamic coefficients for the projectile is determined using static and dynamic CFD methods. This discrete database and the data extracted from free-flight experiments are used to simulate flight trajectories with an in-house developed 6DoF solver. Second, the trajectories are simulated solving the 6DoF motion equations directly coupled with time resolved CFD methods. Findings Virtual fly-out simulations using RBD/CFD coupled simulation methods well reproduce the motion behavior shown by the experimental free-flight data. However, using the discrete database of aerodynamic coefficients derived from CFD simulations shows a slightly different flight behavior. Originality/value A discrepancy between CFD 6DoF/RBD simulations and results obtained by the MATLAB 6DoF-solver based on discrete CFD data matrices is shown. It is assumed that not all dynamic effects on the aerodynamics of the projectile are captured by the determination of the force and moment coefficients with CFD simulations based on the classical aerodynamic coefficient decomposition.

POD Analysis of the Wake Development of a Pivoted Circular Cylinder Undergoing Vortex Induced Vibrations

2017 ◽  
Author(s):  
E. Marble ◽  
C. Morton ◽  
S. Yarusevych
Keyword(s):  
Circular Cylinder ◽  
Degrees Of Freedom ◽  
Structural Response ◽  
Cylinder Wake ◽  
Time Resolved ◽  
Vortex Induced Vibrations ◽  
Image Velocimetry ◽  
Pod Analysis ◽  
Component Particle ◽  
Proper Orthogonal

Vortex Induced Vibrations (VIV) of a pivoted circular cylinder with two degrees of freedom are investigated experimentally, focusing on quantifying the wake topology. Experiments are performed in a water tunnel for a pivoted cylinder with a fixed mass ratio of 10.8, moment of inertia ratio of 87.0–109.5, and a diameter-based Reynolds number of 3100. The reduced velocity was varied from 4.42 to 9.05 by varying the natural frequency of the structure. Velocity measurements were performed via time-resolved, two-component Particle Image Velocimetry (PIV), synchronized with cylinder displacement measurements. Time and phase-averaging are employed to analyze the wake development and relate it to the structural response. Proper Orthogonal Decomposition (POD) is utilized to gain insight into the development of coherent structures in the cylinder wake. The observed shedding patterns agree well with the Morse & Williamson [1] shedding map except for the cases at the boundary between 2P and non-synchronized shedding. The results show that the cylinder follows an elliptical trajectory with equal frequency of oscillation in streamwise and transverse directions. For the 2P regime, the tilt and direction of trajectory affect the formation and development of vortices in the wake. This results in a distinct asymmetry about the wake centerline in time-averaged statistics.

scholarly journals Probing light-driven quantum materials with ultrafast resonant inelastic X-ray scattering

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Matteo Mitrano ◽  
Yao Wang
Keyword(s):  
Degrees Of Freedom ◽  
Spectroscopic Method ◽  
Future Research ◽  
Time Resolved ◽  
X Ray ◽  
Ultrafast Optical ◽  
X Ray Scattering ◽  
Quantum Materials ◽  
Review State ◽  
Ray Scattering

Abstract Ultrafast optical pulses are an increasingly important tool for controlling quantum materials and triggering novel photo-induced phase transitions. Understanding these dynamic phenomena requires a probe sensitive to spin, charge, and orbital degrees of freedom. Time-resolved resonant inelastic X-ray scattering (trRIXS) is an emerging spectroscopic method, which responds to this need by providing unprecedented access to the finite-momentum fluctuation spectrum of photoexcited solids. In this Perspective, we briefly review state-of-the-art trRIXS experiments on condensed matter systems, as well as recent theoretical advances. We then describe future research opportunities in the context of light control of quantum matter.

scholarly journals Coincident angle-resolved state-selective EUV photoelectron spectroscopy of acetylene molecules: a candidate system for time-resolved dynamics

2021 ◽  
Author(s):  
suddhasattwa mandal ◽  
Ram Gopal ◽  
Hemkumar Srinivas ◽  
Alessandro D'Elia ◽  
Arnab Sen ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Degrees Of Freedom ◽  
Dynamical Processes ◽  
Time Resolved

The acetylene-vinylidene system serves as a benchmark for investigations of ultrafast dynamical processes where the coupling of the electronic and nuclear degrees of freedom provides a fertile playground to explore...

scholarly journals Coherent electric field manipulation of Fe3+ spins in PbTiO3

2021 ◽  
Vol 7 (10) ◽  
pp. eabf8103
Author(s):  
Junjie Liu ◽  
Valentin V. Laguta ◽  
Katherine Inzani ◽  
Weichuan Huang ◽  
Sujit Das ◽  
...  
Keyword(s):  
Electric Field ◽  
Degrees Of Freedom ◽  
Coherent Control ◽  
Polar Axis ◽  
Ferric Ion ◽  
Paramagnetic Resonance ◽  
Time Resolved ◽  
Spin Charge Coupling ◽  
Electron Paramagnetic ◽  
Field Manipulation

Magnetoelectrics, materials that exhibit coupling between magnetic and electric degrees of freedom, not only offer a rich environment for studying the fundamental materials physics of spin-charge coupling but also present opportunities for future information technology paradigms. We present results of electric field manipulation of spins in a ferroelectric medium using dilute ferric ion–doped lead titanate as a model system. Combining first-principles calculations and electron paramagnetic resonance (EPR), we show that the ferric ion spins are preferentially aligned perpendicular to the ferroelectric polar axis, which we can manipulate using an electric field. We also demonstrate coherent control of the phase of spin superpositions by applying electric field pulses during time-resolved EPR measurements. Our results suggest a new pathway toward the manipulation of spins for quantum and classical spintronics.

Experimental investigation of freely falling thin disks. Part 1. The flow structures and Reynolds number effects on the zigzag motion

2013 ◽  
Vol 716 ◽  
pp. 228-250 ◽  
Author(s):  
Hongjie Zhong ◽  
Cunbiao Lee ◽  
Zhuang Su ◽  
Shiyi Chen ◽  
Mingde Zhou ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Reynolds Number ◽  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Vortex Pair ◽  
Leading Edge ◽  
Circular Disk ◽  
Stereoscopic Vision ◽  
Time Resolved ◽  
Dipole Vortex

AbstractThis paper describes an experimental investigation of the dynamics of a freely falling thin circular disk in still water. The flow patterns of the disk zigzag motion are studied using dye visualization and particle image velocimetry. Time-resolved disk motions with six degrees of freedom are obtained with a stereoscopic vision method. The flow separation and vortex shedding are found to change with the Reynolds number, $\mathit{Re}$. At high Reynolds numbers a new dipole vortex is shed that is significantly different from Kármán-type vortices. The vortical structures are mainly composed of leading-edge vortices, a counter-rotating vortex pair and secondary trailing-edge vortices. The amplitude of the horizontal oscillation is also dependent on the Reynolds number with a critical Reynolds number ${\mathit{Re}}_{cr} \approx 2000$, where the oscillatory amplitude is proportional to $\mathit{Re}$ for $\mathit{Re}\lt {\mathit{Re}}_{cr} $, but becomes invariant for $\mathit{Re}\gt {\mathit{Re}}_{cr} $. Three-dimensional dipolar vortices were also observed experimentally.

scholarly journals Quantum state tomography of molecules by ultrafast diffraction

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ming Zhang ◽  
Shuqiao Zhang ◽  
Yanwei Xiong ◽  
Hankai Zhang ◽  
Anatoly A. Ischenko ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Quantum State ◽  
Degrees Of Freedom ◽  
Molecular Structures ◽  
Electron Diffraction Data ◽  
Ultrafast Electron Diffraction ◽  
Time Resolved ◽  
Quantum State Tomography ◽  
New Variant ◽  
State Tomography

AbstractUltrafast electron diffraction and time-resolved serial crystallography are the basis of the ongoing revolution in capturing at the atomic level of detail the structural dynamics of molecules. However, most experiments capture only the probability density of the nuclear wavepackets to determine the time-dependent molecular structures, while the full quantum state has not been accessed. Here, we introduce a framework for the preparation and ultrafast coherent diffraction from rotational wave packets of molecules, and we establish a new variant of quantum state tomography for ultrafast electron diffraction to characterize the molecular quantum states. The ability to reconstruct the density matrix, which encodes the amplitude and phase of the wavepacket, for molecules of arbitrary degrees of freedom, will enable the reconstruction of a quantum molecular movie from experimental x-ray or electron diffraction data.

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