Publications associées à Residual entropy

Fully solvable finite simplex lattices with open boundaries in arbitrary dimensions

Finite simplex lattice models are used in different branches of science, e.g., in condensed-matter physics, when studying frustrated magnetic systems and non-Hermitian localization phenomena; or in chemistry, when describing experiments with mixtures. An n ...

Amer Physical Soc2023

Tensor network investigation of frustrated Ising models

Jeanne Colbois

In spin systems, geometrical frustration describes the impossibility of minimizing simultaneously all the interactions in a Hamiltonian, often giving rise to macroscopic ground-state degeneracies and emergent low-temperature physics. In this thesis, combin ...

EPFL2022

Level crossings and chiral transitions in transverse-field Ising models of adatom and Rydberg chains

Ivo Aguiar Maceira

This thesis is motivated by recent experiments on systems described by extensions of the one-dimensional transverse-field Ising (TFI) model where (1) finite-size properties of Ising-ordered phases -- specifically, ground state level crossings -- were obser ...

EPFL2022

Solving frustrated Ising models using tensor networks

Frédéric Mila, Jeanne Colbois

Motivated by the recent success of tensor networks to calculate the residual entropy of spin ice and kagome Ising models, we develop a general framework to study frustrated Ising models in terms of infinite tensor networks that can be contracted using stan ...

2021

Multiple Magnetic Bilayers and Unconventional Criticality without Frustration in BaCuSi2O6

Frédéric Mila, Bruce Normand, Gregory Scott Tucker, Christian Rüegg, Nicolas Laflorencie

The dimerized quantum magnet BaCuSi2O6 was proposed as an example of "dimensional reduction" arising near the magnetic-field-induced quantum critical point (QCP) due to perfect geometrical frustration of its interbilayer interactions. We demonstrate by hig ...

2020

Predicting polymorphism in molecular crystals using orientational entropy

Pablo Miguel Piaggi, Michele Parrinello

We introduce a computational method to discover polymorphs in molecular crystals at finite temperature. The method is based on reproducing the crystallization process starting from the liquid and letting the system discover the relevant polymorphs. This id ...

National Academy of Sciences2018

Dimerization and exotic criticality in spin-S chains

Natalia Chepiga

In this thesis we have studied the emergence of spontaneously dimerized phases in frustrated spin-S chains, with emphasis on the nature of the critical lines between the dimerized and non-dimerized phases. The main numerical method used in this thesis is t ...

EPFL2017

Exchange anisotropy as mechanism for spin-stripe formation in frustrated spin chains

Helmuth Berger

We investigate the spin-stripe mechanism responsible for the peculiar nanometer modulation of the incommensurate magnetic order that emerges between the vector-chiral and the spin-density-wave phase in the frustrated zigzag spin-1/2 chain compound beta-TeV ...

Amer Physical Soc2016

Low-temperature spin dynamics of a valence bond glass in Ba2YMoO6

Henrik Moodysson Rønnow, Julian Piatek

We carried out ac magnetic susceptibility measurements and muon spin relaxation spectroscopy on the cubic double perovskite Ba2YMoO6, down to 50 mK. Below similar to 1 K the muon relaxation is typical of a magnetic insulator with a spin-liquid type ground ...

Institute of Physics (IoP) and Deutsche Physikalische Gesellschaft2013

Atomic structure of the two intermediate phase glasses SiSe4 and GeSe4

Alfredo Pasquarello

The microscopic origin of the intermediate phase in two prototypical covalently bonded A(x)B(1-x) network glass forming systems, where A=Ge or Si, B=Se, and 0

2009

Determination of the single-ion anisotropy energy in a S=5/2 kagome antiferromagnet using x-ray absorption spectroscopy

Henrik Moodysson Rønnow, Goran Nilsen

We report x-ray absorption and x-ray linear dichroism measurements at the Fe L-2,L-3 edges of the geometrically frustrated systems of potassium and hydronium iron jarosite. Comparison with simulated spectra, involving ligand-field multiplet calculations mo ...

2009

Exotic phases of quantum frustrated magnets : magnetization plateaus, nematic order and supersolid phases

Julien Dorier

In this work, we study two examples of frustrated magnetic systems whose degrees of freedom are spins (or pseudo-spins) on two-dimensional lattices. The first part presents the results obtained for the quantum compass model on a square lattice. This model ...

EPFL2008

Quantum helimagnetism of the frustrated spin-(1)/(2) chain LiCuVO4

Henrik Moodysson Rønnow, Mechthild Enderle

Inelastic neutron scattering, susceptibility, and high-field magnetization identify LiCuVO4 as a nearest-neighbour ferromagnetic, next-nearest-neighbour frustrated, quasi-one-dimensional helimagnet, which is largely influenced by quantum fluctuations. Comp ...

IOP Publishing - EPL Association2005