Publications associées à Phase géométrique

Phonon Self-Energy Corrections: To Screen, or Not to Screen

First-principles calculations of phonons are often based on the adiabatic approximation and on Brillouinzone samplings that might not always be sufficient to capture the subtleties of Kohn anomalies. These shortcomings can be addressed through corrections ...

American Physical Society2023

Spin Evolution in the Born-Oppenheimer Approximation

Jean-Philippe Ansermet, François Reuse, Klaus Maschke

The first part of this article attempts to highlight in chronological order some prominent papers that have direct connexion with the Born-Oppenheimer approximation. This timeline successively points to the role of level crossing, the notions of gauge fiel ...

WILEY-V C H VERLAG GMBH2022

Effect of collisions on non-adiabatic electron dynamics in ITG-driven microturbulence

Stephan Brunner, Justin Richard Ball

Non-adiabatic electron response leads to significant changes in ion temperature gradient (ITG) eigenmodes, leading, in particular, to fine-structures that are significantly extended along the magnetic field lines at corresponding mode rational surfaces (MR ...

2021

Simultaneous Perturbation Stochastic Approximation of the Quantum Fisher Information

Giuseppe Carleo, Julien Sebastian Gacon, Stefan Woerner

The Quantum Fisher Information matrix (QFIM) is a central metric in promising algorithms, such as Quantum Natural Gradient Descent and Variational Quantum Imaginary Time Evolution. Computing the full QFIM for a model with d parameters, however, is computat ...

VEREIN FORDERUNG OPEN ACCESS PUBLIZIERENS QUANTENWISSENSCHAF2021

Which form of the molecular Hamiltonian is the most suitable for simulating the nonadiabatic quantum dynamics at a conical intersection?

Jiri Vanicek, Seonghoon Choi

Choosing an appropriate representation of the molecular Hamiltonian is one of the challenges faced by simulations of the nonadiabatic quantum dynamics around a conical intersection. The adiabatic, exact quasidiabatic, and strictly diabatic representations ...

2020

Silicon Photonic MEMS Phase-Shifter

Niels Quack, Hamed Sattari, Teodoro Graziosi, Marcell Kristof Kiss

We present a design for an analog phase shifter based on Silicon Photonic MEMS technology. The operation principle is based on a two-step parallel plate electrostatic actuation mechanism to bring a vertically movable suspended tapered waveguide in a first ...

2019

Improved off‐resonance phase behavior using a phase‐inverted adiabatic half‐passage pulse for 13 C MRS in humans at 7 T

Rolf Gruetter, Lijing Xin, Daniel Gallichan, Eulalia Serés Roig

In vivo (13) C MRS at high field benefits from an improved SNR and spectral resolution especially when using surface coils in combination with adiabatic pulses, such as the adiabatic half-passage (AHP) pulse for (13) C excitation. However, the excitation p ...

2019

Linear collisionless dynamics of the GAM with kinetic electrons: Comparison simulations/theory

Alberto Bottino

Barely trapped and passing electrons have been recently predicted to strongly enhance the damping rate of Geodesic Acoustic Modes (GAMs) in tokamak plasmas, while keeping their real frequency almost unchanged as compared to the case with adiabatic electron ...

AMER INST PHYSICS2019

Parameters affecting thermal risk through a kinetic model under adiabatic condition: Application to liquid-liquid reaction system

Thierry Meyer

Risk of thermal runaway for epoxidation is not negligible and should be analyzed and assessed. In industry, epoxidation of vegetable oils is carried out by the oxidation of Prileschajew, involving the in situ production of percarboxylic acid from hydrogen ...

2018

Geometric phases in discrete dynamical systems

Nicolas Piro Mastracchio

In order to study the behaviour of discrete dynamical systems under adiabatic cyclic variations of their parameters, we consider discrete versions of adiabatically-rotated rotators. Parallelling the studies in continuous systems, we generalize the concept ...

Elsevier Science Bv2016