Publications related to Ising critical exponents

Primary and secondary order parameters in the fully frustrated transverse-field Ising model on the square lattice

Using quantum Monte Carlo simulations and field-theory arguments, we study the fully frustrated transversefield Ising model on the square lattice for the purpose of quantitatively relating two different order parameters to each other. We consider a "primar ...

Amer Physical Soc2024

Eight-vertex criticality in the interacting Kitaev chain

Frédéric Mila, Natalia Chepiga

We show that including pairing and repulsion into the description of one-dimensional spinless fermions, as in the domain wall theory of commensurate melting or the interacting Kitaev chain, leads, for strong enough repulsion, to a line of critical points i ...

AMER PHYSICAL SOC2023

Nonperturbative aspects of scattering amplitudes

Miguel Alexandre Ribeiro Correia

In this thesis we study how physical principles imposed on the S-matrix, such as Lorentz invariance, unitarity, crossing symmetry and analyticity constrain quantum field theories at the nonperturbative level. We start with a pedagogical introduction to the ...

EPFL2023

Thermal Ising Transition in the Spin-1/2 J(1)-J(2) Heisenberg Model

Frédéric Mila, Olivier Clément Romain Gauthé

Using an SU(2) invariant finite-temperature tensor network algorithm, we provide strong numerical evidence in favor of an Ising transition in the collinear phase of the spin-1/2 J(1)-J(2) Heisenberg model on the square lattice. In units of J(2), the critic ...

2022

Inception of Regular Valley Spacing in Fluvial Landscapes: A Linear Stability Analysis

Sara Bonetti, Shashank Kumar Anand

Incipient valley formation in mountainous landscapes is often associated with their presence at a regular spacing under diverse hydroclimatic forcings. Here we provide a formal linear stability theory for a landscape evolution model (LEM) representing the ...

2022

Conformal Field Theory at the Lattice Level: Discrete Complex Analysis and Virasoro Structure

Clément Hongler

Critical statistical mechanics and Conformal Field Theory (CFT) are conjecturally connected since the seminal work of Beliavin et al. (Nucl Phys B 241(2):333-380, 1984). Both exhibit exactly solvable structures in two dimensions. A long-standing question ( ...

SPRINGER2022

A numerical study of the statistics of roughness parameters for fluctuating interfaces

Elisabeth Agoritsas

Self-affine rough interfaces are ubiquitous in experimental systems, and display characteristic scaling properties as a signature of the nature of disorder in their supporting medium, i.e. of the statistical features of its heterogeneities. Different metho ...

2021

A quantum magnetic analogue to the critical point of water

Henrik Moodysson Rønnow, Frédéric Mila, Bruce Normand, Christian Rüegg, Ludger Weber, Ellen Fogh, Mohamed Zayed, Julio Antonio Larrea Jiménez, Kazimierz Conder

At the liquid-gas phase transition in water, the density has a discontinuity at atmospheric pressure; however, the line of these first-order transitions defined by increasing the applied pressure terminates at the critical point(1), a concept ubiquitous in ...

2021

On the fractal structure of soil moisture fields

Andrea Rinaldo

We study the spatial structure of soil moisture fields within savanna ecosystems, whose persistence is vital because it is the driver of the entire ecological structure and function. These include changes in the physical and biogeochemical conditions of th ...

ELSEVIER SCI LTD2021

Gaussian Multiplicative Chaos Through the Lens of the 2D Gaussian Free Field

Juhan Aru

The aim of this review-style paper is to provide a concise, self-contained and unified presentation of the construction and main properties of Gaussian multiplicative chaos (GMC) measures for log-correlated fields in 2D in the subcritical regime. By consid ...

POLYMAT2020

Carving out OPE space and precise O(2) model critical exponents

Alessandro Vichi, Ning Su

We develop new tools for isolating CFTs using the numerical bootstrap. A "cutting surface" algorithm for scanning OPE coefficients makes it possible to find islands in high-dimensional spaces. Together with recent progress in large-scale semidefinite progr ...

Springer Nature2020

Infinitesimal asphericity changes the universality of the jamming transition

Matthieu Wyart, Carolina Brito Carvalho dos Santos

The jamming transition of non-spherical particles is fundamentally different from the spherical case. Non-spherical particles are hypostatic at their jamming points, while isostaticity is ensured in the case of the jamming of spherical particles. This stru ...

IOP PUBLISHING LTD2020

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

DMRG investigation of constrained models: from quantum dimer and quantum loop ladders to hard-boson and Fibonacci anyon chains

Frédéric Mila, Natalia Chepiga

Motivated by the presence of Ising transitions that take place entirely in the singlet sector of frustrated spin-1/2 ladders and spin-1 chains, we study two types of effective dimer models on ladders, a quantum dimer model and a quantum loop model. Buildin ...

2019

Ising Model and Field Theory: Lattice Local Fields and Massive Scaling Limit

Sung Chul Park

This thesis is devoted to the study of the local fields in the Ising model. The scaling limit of the critical Ising model is conjecturally described by Conformal Field Theory. The explicit predictions for the building blocks of the continuum theory (spin a ...

EPFL2019

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

Quantum Critical Regime in a Quadratically Driven Nonlinear Photonic Lattice

Vincenzo Savona, Riccardo Rota, Fabrizio Minganti, Cristiano Ciuti

We study an array of coupled optical cavities in the presence of two-photon driving and dissipation. The system displays a critical behavior similar to that of a quantum Ising model at finite temperature. Using the corner-space renormalization method, we c ...

AMER PHYSICAL SOC2019

Ising Model: Local Spin Correlations and Conformal Invariance

Clément Hongler, Sung Chul Park

We study the 2-dimensional Ising model at critical temperature on a simply connected subset of the square grid Z2. The scaling limit of the critical Ising model is conjectured to be described by Conformal Field Theory; in particular, there is expected to b ...

Springer2019

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

The conformal bootstrap: Theory, numerical techniques, and applications

Alessandro Vichi

Conformal field theories have been long known to describe the fascinating universal physics of scale invariant critical points. They describe continuous phase transitions in fluids, magnets, and numerous other materials, while at the same time sit at the h ...

AMER PHYSICAL SOC2019