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Concept

Spinon

Publications associées (24)

Nonlinear optical diode effect in a magnetic Weyl semimetal

Philip Johannes Walter Moll, Chunyu Guo

Diode effects are of great interest for both fundamental physics and modern technologies. Electrical diode effects (nonreciprocal transport) have been observed in Weyl systems. Optical diode effects arising from the Weyl fermions have been theoretically co ...

Nature Portfolio2024

Hole-induced anomaly in the thermodynamic behavior of a one-dimensional Bose gas

Riccardo Rota

We reveal an intriguing anomaly in the temperature dependence of the specific heat of a one-dimensional Bose gas. The observed peak holds for arbitrary interaction and remembers a superfluid-to-normal phase transition in higher dimensions, but phase transi ...

SCIPOST FOUNDATION2022

Static and dynamic properties of non-collinear quantum antiferromagnets explored by neutron scattering

Luc Testa

This thesis is devoted to the investigation of static and dynamic properties of two different sets of quantum magnets with neutron scattering techniques and the help of linear spin wave theory. Both systems are copper-based with spin-1/2, which makes them ...

EPFL2021

Spinon confinement and deconfinement in spin-1 chains

Frédéric Mila, Natalia Chepiga

Motivated by the rich phase diagrams recently unveiled in frustrated spin-1 chains with competing next-nearest-neighbor and four-spin interactions, we investigate the nature of the elementary excitations of spin-1 chains in the vicinity of phase transition ...

2020

Magnetic ground state of the frustrated spin-1/2 chain compound beta-TeVO4 at high magnetic fields

Helmuth Berger, Jonathan White

Frustrated spin-1/2 chains, despite the apparent simplicity, exhibit a remarkably rich phase diagram comprising vector-chiral (VC), spin-density-wave (SDW), and multipolar/spin-nematic phases as a function of the magnetic field. Here we report a study of b ...

2019

Coexisting spinons and magnons in the frustrated zigzag spin-1/2 chain compound beta-TeVO4

Helmuth Berger

We investigate magnetic excitations in the frustrated zigzag spin-1/2 chain compound beta-TeVO4 by inelastic neutron scattering. In the magnetically ordered ground state, the excitation spectrum exhibits coexisting magnon dispersion, characteristic of long ...

AMER PHYSICAL SOC2018

Probing multi-spinon excitations outside of the two-spinon continuum in the antiferromagnetic spin chain cuprate Sr2CuO3

Henrik Moodysson Rønnow, Thorsten Schmitt, Martin Mourigal

One-dimensional (1D) magnetic insulators have attracted significant interest as a platform for studying quasiparticle fractionalization, quantum criticality, and emergent phenomena. The spin-1/2 Heisenberg chain with antiferromagnetic nearest neighbour int ...

Nature Research2018

Kinetic Monte Carlo approach to nonequilibrium bosonic systems

Hugo Pierre Alexandre Flayac, Timothy Chi Hin Liew

We consider the use of a kinetic Monte Carlo approach for the description of nonequilibrium bosonic systems, taking nonresonantly excited exciton-polariton condensates and bosonic cascade lasers as examples. In the former case, the considered approach allo ...

Amer Physical Soc2017

Multivalley engineering in semiconductor microcavities

Hugo Pierre Alexandre Flayac, Timothy Chi Hin Liew

We consider exciton-photon coupling in semiconductor microcavities in which separate periodic potentials have been embedded for excitons and photons. We show theoretically that this system supports degenerate ground-states appearing at non-zero inplane mom ...

Springer Nature2017

Luttinger liquid behavior in the alternating spin-chain system copper nitrate

Felix Groitl

We determine the phase diagram of copper nitrate Cu(NO3)(2)center dot 2.5D(2)O in the context of quantum phase transitions and novel states of matter. We establish this compound as an ideal candidate to study quasi-1D Luttinger liquids, 3D Bose-Einstein-Co ...

American Physical Society2015

Magnons in tetragonal CuO

Henrik Moodysson Rønnow, Frédéric Mila, Marco Grioni, Thorsten Schmitt, Simon Karl Moser, Bastien Dalla Piazza, Noore Elahi Shaik, Sara Fatale

We investigate by resonant inelastic x-ray scattering the magnetic excitations in thin films of tetragonal CuO. We identify a spin wave excitation, dispersing on two cupratelike antiferromagnetic sublattices. Its energy at the boundary of the Brillouin zon ...

2015

Noise-Induced Phenomena in Collective Spinor Polariton Excitations

Hadis Abbaspour

Polaritons are quasiparticles resulting from the strong coupling between photons and excitons embedded in a semiconductor microcavity. The exciton component of polaritons provides strong nonlinear interactions, while their photonic counterpart facilitates ...

EPFL2015

Direct measurement of the bulk spin structure of noncentrosymmetric BiTeCl

Jan Hugo Dil, Stefan Peter Muff

A strong spin-orbit interaction leads to a Rashba-type splitting of the bulk bands of BiTeCl, which results in toroidal Fermi surfaces with distinct spin structures depending on the chemical potential. Here, we present spin-and angle-resolved photoelectron ...

American Physical Society2015

Nonlinear relaxation and selective polychromatic lasing of confined polaritons

Benoît Marie Joseph Deveaud, François Morier-Genoud, Marcia Portella Oberli, Gabriele Grosso, Stéphane Trebaol

Polaritons have often been proposed as promising candidates for the realization of all-optical devices due to the easy manipulation and control of their density and spin. In this paper we present a relaxation mechanism for confined polaritons and its appli ...

Amer Physical Soc2014

Interplay of Dirac fermions and heavy quasiparticles in solids

Thorsten Schmitt

Many-body interactions in crystalline solids can be conveniently described in terms of quasiparticles with strongly renormalized masses as compared with those of non-interacting particles. Examples of extreme mass renormalization are on the one hand graphe ...

Nature Publishing Group2013

Spin-orbital separation in the quasi-one-dimensional Mott insulator Sr2CuO3

Henrik Moodysson Rønnow, Thorsten Schmitt, Martin Mourigal

When viewed as an elementary particle, the electron has spin and charge. When binding to the atomic nucleus, it also acquires an angular momentum quantum number corresponding to the quantized atomic orbital it occupies. Even if electrons in solids form ban ...

2012

Anomalously enhanced photoemission from the Dirac point and other peculiarities in the self-energy of the surface-state quasiparticles in Bi2Se3

Helmuth Berger

Line-shape analysis of the photoemission intensity from the surface states of Bi2Se3 reveals two unusual features: spectral line asymmetry and anomalously enhanced photoemission from the Dirac point. The former can be described by the one-particle spectral ...

2012

Experimental evidence for Luttinger liquid behavior in sufficiently long GaAs V-groove quantum wires

Elyahou Kapon, Alok Rudra, Benjamin Dwir

We have measured the temperature dependence of the conductance of long V-groove quantum wires fabricated using GaAs/AlGaAs heterostructures, in a wide temperature range (200 mK < T < 4.2 K). We find that for our quantum wires the Fermi velocity can be as l ...

2012

Probability density optical tomography of confined quasiparticles in a semiconductor microcavity

Benoît Marie Joseph Deveaud, François Morier-Genoud, Gaël Nardin, Ounsi El Daïf, Taofiq Paraïso, Barbara Pietka, Roland Cerna

We present the optical tomography of the probability density of quasiparticles, the microcavity polaritons, confined in three dimensions by cylindrical traps. Collecting the photoluminescence emitted by the quasimodes under continuous nonresonant laser exc ...

AIP American Institute of Physics2009

Field-controlled magnetic order in the quantum spin-ladder system (Hpip)2CuBr4

Henrik Moodysson Rønnow, Joël Mesot, Bruce Normand, Christian Rüegg, Pierre Bouillot, Daniel Biner

Neutron diffraction is used to investigate the field-induced, antiferromagnetically ordered state in the two-leg spin-ladder material (Hpip)(2)CuBr4. This "classical" phase, a consequence of weak interladder coupling, is nevertheless highly unconventional: ...

2009