Excitation Spectra of Square Lattice Antiferromagnets

Theoretical Explanation of Experimental Observations
1. Auflage 2016
ISBN: 978-3-319-26418-9
Verlag: Springer International Publishing

Buch, Englisch, 176 Seiten, HC runder Rücken kaschiert, Format (B × H): 160 mm x 241 mm, Gewicht: 4203 g

Reihe: Springer Theses

This thesis presents a qualitative advance in our understanding of quantum effects in layered magnetic materials. The nearest neighbor Heisenberg ferromagnetic ranks among the oldest and most fundamental models of quantum many body effects. It has long been established that in one dimension quantum fluctuations lead to a quantum disordered ground state with fractional excitations called spinons." In two dimensions, the ground state of the Heisenberg model displays static order and to first approximation the dynamics can be described as semi-classical spin waves. Through theoretical advances the author demonstrates that at high energy around particular points in reciprocal space these semi-classical spin-waves deconfine into fractional excitations akin to the one-dimensional spinons. He thereby provides the first explanation of a long-standing experimental observation.

In the second half of his thesis Bastien Dalla Piazza develops a unified description of the magnetic excitation spectra of a range of cuprate parent compounds to the high temperature superconductors.

Zielgruppe

Research

Autoren/Hrsg.

Dalla Piazza, Bastien

Fachgebiete

• Technische Wissenschaften Maschinenbau | Werkstoffkunde Technische Mechanik | Werkstoffkunde Materialwissenschaft: Elektronik, Optik
• Naturwissenschaften Physik Thermodynamik Festkörperphysik, Kondensierte Materie
• Naturwissenschaften Physik Elektromagnetismus Magnetismus
• Naturwissenschaften Physik Quantenphysik

Inhaltsverzeichnis

Introduction.- Variational Study of the Square Lattice Anti-ferromagnet Magnetic Zone-Boundary Anomaly.- Modeling the Spin-Wave Dispersion of Insulating Cuprate Materials.

Über Autor(innen)

After
a brief excursion into literature studies at the University of Lausanne, Bastien
Dalla Piazza began his physics studies at the École Polytechnique Fédérale de
Lausanne (EPFL) where he obtained his master’s degree and later his Physics
PhD, having worked on exotic properties of some magnetic materials using
massively parallel supercomputers. Following his PhD, he joined Nanolive SA, a
start-up developing the first commercial implementation of a tomographic phase
microscope.