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Concept

Fractionalisation

Publications associées (31)

Neutron spectroscopy in the layered quantum magnet SrCu₂(BO₃)₂ and in transition metal phosphorus trisulfides (MPS₃)

Diane Virginie Marie Lançon

Collective magnetic excitations are a fascinating aspect of condensed matter physics, where neutron scattering can provide valuable insight into the magnetic properties of physical realisations of model systems. This thesis focuses on the excitation spectr ...

EPFL2017

Neutron Larmor diffraction investigation of the rare-earth pyrochlores R2Ti2O7 (R = Tb, Dy, Ho)

Thomas Keller, Felix Groitl

In this work, we present a neutron Larmor diffraction study of the rare-earth pyrochlores R2Ti2O7 with R = Tb, Dy, Ho. We measured the temperature dependence of the lattice parameter with precision 10(-5), between 0.5 and 300 K in each of the three compoun ...

Amer Physical Soc2016

Non-Zhang-Rice Singlet Character of the First Ionization State of T-CuO

Simon Karl Moser

We argue that tetragonal CuO (T-CuO) has the potential to finally settle long-standing modeling issues for cuprate physics. We compare the one-hole quasiparticle (qp) dispersion of T-CuO to that of cuprates, in the framework of the strongly correlated (U-d ...

Amer Physical Soc2016

Fractional excitations in the square-lattice quantum antiferromagnet

Henrik Moodysson Rønnow, Dmitri Ivanov, Bastien Dalla Piazza, Martin Mourigal

Quantum magnets have occupied the fertile ground between many-body theory and low-temperature experiments on real materials since the early days of quantum mechanics. However, our understanding of even deceptively simple systems of interacting spin-1/2 par ...

Nature Publishing Group2015

Universal helimagnon and skyrmion excitations in metallic, semiconducting and insulating chiral magnets

Helmuth Berger, Dirk Grundler

Nearly seven decades of research on microwave excitations of magnetic materials have led to a wide range of applications in electronics(1-4). The recent discovery of topological spin solitons in chiral magnets, so-called skyrmions(5-9), promises high-frequ ...

Nature Publishing Group2015

Theories of Experimentally Observed Excitation Spectra of Square Lattice Antiferromagnets

Bastien Dalla Piazza

The first part of this thesis presents the theoretical study of an anomaly of unknown origin in the excitation spectrum of the Quantumspin-1/2 Heisenberg Square lattice Anti-Ferromagnet. The anomaly manifests itself in Inelastic Neutron Scattering data for ...

EPFL2014

Elementary Excitations of Superfluid Helium Droplets Probed by Ion Spectroscopy

Marcel Drabbels, Xiaohang Zhang

Electronic spectra of molecules in helium droplets reveal spectral features that are related to the elementary excitations of the superfluid helium environment. In order to determine to what extend the interaction strength of the molecule with the helium a ...

Amer Chemical 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

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

The Quantum Magnetism of Individual Manganese-12-Acetate Molecular Magnets Anchored at Surfaces

Klaus Kern, Stephan Rauschenbach, Markus Ternes, Gordon Rinke

The high intrinsic spin and long spin relaxation time of manganese-12-acetate (Mn-12) makes it an archetypical single molecular magnet. While these characteristics have been measured on bulk samples, questions remain whether the magnetic properties replica ...

American Chemical Society (ACS)2012

Phase diagram and continuous pair-unbinding transition of the bilinear-biquadratic S=1 Heisenberg chain in a magnetic field

Frédéric Mila

We investigate the properties of the Heisenberg S = 1 chain with bilinear and biquadratic interactions in a magnetic field using the density-matrix renormalization-group, Bethe ansatz, and field-theoretical considerations. In a large region of the paramete ...

2011