Publications associées à Static forces and virtual-particle exchange

Universal Casimir attraction between filaments at the cell scale

The electromagnetic Casimir interaction between dielectric objects immersed in salted water includes a universal contribution that is not screened by the solvent and therefore long-ranged. Here, we study the geometry of two parallel dielectric cylinders. W ...

Iop Publishing Ltd2024

Realization of an atomic quantum Hall system in four dimensions

Qi Liu

Modern condensed matter physics relies on the concept of topology to classify matter, from quantum Hall systems to topological insulators. Engineered systems, benefiting from synthetic dimensions, can potentially give access to topological states predicted ...

American Association for the Advancement of Science2024

Reconfigurable nonreciprocal excitation of propagating exchange spin waves in perpendicularly magnetized yttrium iron garnet thin films

Jean-Philippe Ansermet, Haiming Yu, Yu Zhang, Peng Chen, Jilei Chen, Tao Liu, Jinlong Wang, Rundong Yuan

We report the nonreciprocal excitation of propagating forward volume exchange spin waves in yttrium iron garnet (YIG) thin film with perpendicular anisotropy by bringing the in-plane magnetization of Co20Fe60B20 (CoFeB) nanowires to resonance. All-electric ...

Amer Physical Soc2023

Confined dipole and exchange spin waves in a bulk chiral magnet with Dzyaloshinskii-Moriya interaction

Dirk Grundler, Ping Che, Andrea Mucchietto, Helmuth Berger, Jianing Li

The Dzyaloshinskii-Moriya interaction (DMI) has an impact on excited spin waves in the chiral magnet Cu2OSeO3 by means of introducing asymmetry in their dispersion relations. The confined eigenmodes of a chiral magnet are hence no longer the conventional s ...

2021

Nanophotonic structures with optical surface modes for tunable spin current generation

Serguei Sekatski, Pavel Kapralov

We propose a novel type of photonic-crystal (PC)-based nanostructures for efficient and tunable optically-induced spin current generation via the spin Seebeck and inverse spin Hall effects. It has been experimentally demonstrated that optical surface modes ...

ROYAL SOC CHEMISTRY2021

Pure Spin Current and Magnon Chemical Potential in a Nonequilibrium Magnetic Insulator

Kyongmo An, Li Shi

Nonequilibrium phenomena are ubiquitous in nature and in a wide range of systems, including cold atomic gases and solid-state materials. While these phenomena are challenging to describe both theoretically and experimentally, they are essential for the fun ...

American Physical Society2020

Mahan excitons in room-temperature methylammonium lead bromide perovskites

Majed Chergui, László Forró, Endre Horvath, Ana Akrap, Edoardo Baldini, Márton Kollár, Tania Palmieri

In a seminal paper, Mahan predicted that excitonic bound states can still exist in a semiconductor at electron-hole densities above the insulator-to-metal Mott transition. However, no clear evidence for this exotic quasiparticle, dubbed Mahan exciton, exis ...

Nature Publishing Group2020

Perturbative approach to tunneling and quantum interferences in spin clusters

Frédéric Mila, Ivo Aguiar Maceira

Collective tunneling is a ubiquitous phenomenon in finite-size spin clusters that shows up in systems as diverse as molecular magnets or spin clusters adsorbed at surfaces. The basic problem we explore is to understand how small flipping terms can cooperat ...

2020

Koopmans Meets Bethe-Salpeter: Excitonic Optical Spectra without GW

Nicola Marzari, Nicola Colonna, Paolo Umari

The Bethe Salpeter equation (BSE) can be applied to compute from first-principles optical spectra that include the effects of screened electron hole interactions. As input, BSE calculations require single-particle states, quasiparticle energy levels, and t ...

AMER CHEMICAL SOC2019

Elementary excitation in the spin-stripe phase in quantum chains

Helmuth Berger, Jonathan White

Elementary excitations in condensed matter capture the complex many-body dynamics of interacting basic entities in a simple quasiparticle picture. In magnetic systems the most established quasiparticles are magnons, collective excitations that reside in or ...

Springer2019

Graviton scattering and a sum rule for the c anomaly in 4D CFT

Marc Gillioz

4D CFTs have a scale anomaly characterized by the coefficient c, which appears as the coefficient of logarithmic terms in momentum space correlation functions of the energy-momentum tensor. By studying the CFT contribution to 4-point graviton scattering am ...

Springer Nature2018

Spectral properties of a symmetric three-dimensional quantum dot with a pair of identical attractive delta-impurities symmetrically situated around the origin

Fabio Rinaldi

In this presentation, we wish to provide an overview of the spectral features for the self-adjoint Hamiltonian of the three-dimensional isotropic harmonic oscillator perturbed by either a single attractive delta-interaction centered at the origin or by a p ...

St Petersburg Natl Research Univ Information Technologies, Mech & Optics2016

The Hamiltonian of the harmonic oscillator with an attractive delta '-interaction centred at the origin as approximated by the one with a triple of attractive delta-interactions

Fabio Rinaldi

In this note we provide an alternative way of defining the self-adjoint Hamiltonian of the harmonic oscillator perturbed by an attractive delta'-interaction, of strength beta, centred at 0 (the bottom of the confining parabolic potential), that was rigorou ...

Iop Publishing Ltd2016

Magnetic structure and magnon dynamics of the quasi-two-dimensional antiferromagnet FePS3

Henrik Moodysson Rønnow, Diane Virginie Marie Lançon

Neutron scattering from single crystals has been used to determine the magnetic structure and magnon dynamics of FePS3, an S = 2 Ising-like quasi-two-dimensional antiferromagnet with a honeycomb lattice. The magnetic structure has been confirmed to have a ...

Amer Physical Soc2016

Probing the coupling between a doublon excitation and the charge-density wave in TaS2 by ultrafast optical spectroscopy

Arnaud Magrez, Fabrizio Carbone, Edoardo Baldini, Helmuth Berger, Andreas Helmut Christian Mann, Ahmad Odeh

Recently, the switching between the different charge-ordered phases of 1T-TaS2 has been probed by ultrafast techniques, revealing unexpected phenomena such as "hidden" metastable states and peculiar photoexcited charge patterns. Here, we apply broadband pu ...

Amer Physical Soc2016

Two-dimensional short-range interacting attractive and repulsive Fermi gases at zero temperature

Gianluca Bertaina

We study a two-dimensional two-component Fermi gas with attractive or repulsive short-range interactions at zero temperature. We use Diffusion Monte Carlo with Fixed Node approximation in order to calculate the energy per particle and the opposite spin pai ...

Springer2013

Fractional spinon excitations in the quantum Heisenberg antiferromagnetic chain

Henrik Moodysson Rønnow, Martin Mourigal, Jean-Sebastien Caux, Mechthild Enderle

One of the simplest quantum many-body systems is the spin-1/2 Heisenberg antiferromagnetic chain, a linear array of interacting magnetic moments. Its exact ground state is a macroscopic singlet entangling all spins in the chain. Its elementary excitations, ...

Nature Publishing Group2013

Four-lepton production at hadron colliders: aMC@NLO predictions with theoretical uncertainties

Valentin Hirschi, Paolo Torrielli

We use aMC@NLO to study the production of four charged leptons at the LHC, performing parton showers with both HERWIG and PYTHIA6. Our underlying matrix element calculation features the full next-to-leading order O(alpha(S)) result and the O(alpha(2)(S)) c ...

Springer Nature2012

On the Physics of Exciton-Polariton Condensates

Konstantinos Lagoudakis

After the first demonstration of Bose Einstein condensation in the solid state in 2006 and the establishment of exciton polariton condensates in the wider scientific community, an intense interest has been attracted by this phenomenon at both theoretical a ...

EPFL2010

Two-dimensional electrostatic force field measurements with simultaneous topography measurement on embedded interdigitated nanoelectrodes using a force distance curve based method

Patrik Willi Hoffmann, Christian Santschi

Accurate simultaneous measurements on the topography and electrostatic force field of 500 nm pitch interdigitated electrodes embedded in a thin SiO2 layer in a plane perpendicular to the orientation of the electrodes are shown for the first time. A static ...

AIP American Institute of Physics2008