Publications associées à Model Evidence of an Anisotropic Chiral d plus id-Wave Pairing State for the Water-Intercalated NaxCoO2 center dot yH(2)O Superconductor

Topological photonic transport in disordered scattering networks

This Ph.D. thesis unveils the unique topological phenomena occurring in such networks, focusing on the intricate interplay between their Floquet topology, the presence of disorder, and their unitary scattering at microscopic and macroscopic scales. Using t ...

EPFL2024

Holography and localization of information in quantum gravity

Kyriakos Papadodimas, Alexandre Mathieu Frédéric Belin

Within the AdS/CFT correspondence, we identify a class of CFT operators which represent diff-invariant and approximately local observables in the gravitational dual. Provided that the bulk state breaks all asymptotic symmetries, we show that these operator ...

Springer Nature2024

Benchmark exercise on image-based permeability determination of engineering textiles: Microscale predictions

Véronique Michaud, Baris Çaglar, Guillaume Clément Broggi

Permeability measurements of engineering textiles exhibit large variability as no standardization method currently exists; numerical permeability prediction is thus an attractive alternative. It has all advantages of virtual material characterization, incl ...

2023

From SU(2)5 to SU(2)3 Wess-Zumino-Witten transitions in a frustrated spin-52 chain

Frédéric Mila, Natalia Chepiga

We investigate the properties of a frustrated spin-5/2 chain with next-nearest-neighbor two- and three-site interactions, with two questions in mind: the nature of the transition into the dimerized phase induced by the three-site interaction, and the possi ...

2022

Critical values in an anisotropic percolation on $\mathbb{Z}^2$

Hao Xue

In this thesis, we consider an anisotropic finite-range bond percolation model on

\mathbb{Z}^2

. On each horizontal layer

\{(x,i):x\in\mathbb{Z}\}

for

i\in\mathbb{Z}

, we have edges

\langle(x,i),(y,i)\rangle

for

1\leq|x-y|\leq N

with $N\in\mathbb{N ...

EPFL2021

Nonperturbative Mellin Amplitudes

João Pedro Alves Da Silva

Conformal field theory lies at the heart of two central topics in theoretical high energy physics: the study of quantum gravity and the mapping of quantum field theories through the renormalization group. In this thesis we explore a technique to study conf ...

EPFL2021

Facilitating Experiential Learning in Higher Education Teaching and Supervising in Labs, Fieldwork, Studios, and Projects

Siara Ruth Isaac, Roland John Tormey

This book provides evidence-informed and practical advice on how to design, teach, and facilitate hands-on, experiential learning in practical higher education settings. With rich case studies and carefully considered analysis tasks, all underpinned by res ...

Routledge2021

Evidence of a coupled electron-phonon liquid in NbGe2

Mathieu François Padlewski, Philip Johannes Walter Moll, Matthias Carsten Putzke, Hao Yang

Whereas electron-phonon scattering relaxes the electron's momentum in metals, a perpetual exchange of momentum between phonons and electrons may conserve total momentum and lead to a coupled electron-phonon liquid. Such a phase of matter could be a platfor ...

Nature Portfolio2021

Two-dimensional O(n) models and logarithmic CFTs

Bernardo Zan, Victor Gorbenko

We study O(n)-symmetric two-dimensional conformal field theories (CFTs) for a continuous range of n below two. These CFTs describe the fixed point behavior of self-avoiding loops. There is a pair of known fixed points connected by an RG flow. When n is equ ...

Springer Nature2020

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

Floating, critical, and dimerized phases in a frustrated spin-3/2 chain

Frédéric Mila, Natalia Chepiga

We study spontaneous dimerization and emergent criticality in a spin-3/2 chain with antiferromagnetic nearestneighbor J(1), next-nearest-neighbor J(2), and three-site J(3) interactions. In the absence of three-site interaction J(3), we provide evidence tha ...

2020

Towards the renormalization group flow of Horava gravity in 3+1 dimensions

Sergey Sibiryakov, Mario Herrero Valea

We compute the renormalization group running of the Newton constant and the parameter lambda in (3 + 1)-dimensional projectable Horava gravity. We use the background-field method, expanding around configurations with flat spatial metric, but nonvanishing s ...

American Physical Society2019

Hidden and explicit quantum scale invariance

Mikhail Chapochnikov, Thibault Voumard, Sander Johannes Nicolaas Mooij

There exist renormalization schemes that explicitly preserve the scale invariance of a theory at the quantum level. Imposing a scale-invariant renormalization breaks renormalizability and induces new nontrivial operators in the theory. In this work, we stu ...

American Physical Society2019

Studies in strongly coupled quantum field theories and renormalization group flows

Bernardo Zan

This thesis presents studies in strongly coupled Renormalization Group (RG) flows. In the first part, we analyze the subject of non-local Conformal Field Theories (CFTs), arising as continuous phase transitions of statistical models with long-range interac ...

EPFL2019

Quantum phase transitions beyond Landau-Ginzburg theory in one-dimensional space revisited

Christopher Marc Mudry

The phase diagram of the quantum spin-1/2 antiferromagnetic J(1)-J(2) XXZ chain was obtained by Haldane using bosonization techniques [Haldane, Phys. Rev. B 25, 4925 (1982); 26, 5257 (1982)]. It supports three distinct phases for 0

2019

A structural test for the conformal invariance of the critical 3d Ising model

João Miguel Augusto Penedones Fernandes, Pierre Mathieu Yvernay

How can a renormalization group fixed point be scale invariant without being conformal? Polchinski (1988) showed that this may happen if the theory contains a virial current a non-conserved vector operator of dimension exactly (d - 1), whose divergence exp ...

Springer Nature2019

Field-induced anisotropy in the quasi-two-dimensional weakly anisotropic antiferromagnet [CuCl(pyz)(2)]BF4

Henrik Moodysson Rønnow

We measured NMR and magnetic susceptibility for the quasi-two-dimensional, weakly XY-like, spin-1/2 square-lattice Heisenberg antiferromagnet [CuCl(pyz)(2)]BF4 (pyz = pyrazine = N2C4H4) near the critical temperature. The Neel temperature T-N and the order- ...

2019

Kondo lattice excitation observed using resonant inelastic x-ray scattering at the YbM5 edge

Marco Grioni, Marco Guarise, Thorsten Schmitt

We present a study of the resonant inelastic scattering response of YbInCu4 excited at the tender YbM5 x-ray edge. In the high-temperature, paramagnetic phase, we observe a multiplet structure which can be understood at an ionic level. Upon cooling through ...

AMER PHYSICAL SOC2018

Singlet state formation and its impact on the magnetic structure in the tetramer system SeCuO3

Helmuth Berger, Arnaud Magrez, Krunoslav Prsa, Henrik Moodysson Rønnow, Ivica Zivkovic, Peter Babkevich

We present an experimental investigation of the magnetic structure in a tetramer system SeCuO3 using neutron powder-diffraction and nuclear resonance techniques. We establish a commensurate antiferromagnetic ordering with a propagation vector k = (0, 0, 1) ...

2018

Walking, Weak first-order transitions, and Complex CFTs II. Two-dimensional Potts model at Q > 4

Bernardo Zan, Victor Gorbenko

We study complex CFTs describing fixed points of the two-dimensional Q-state Potts model with Q > 4. Their existence is closely related to the weak first-order phase transition and the "walking" renormalization group (RG) behavior present in the real Potts ...

2018