Publications related to Quantum foam

Wigner Gaussian dynamics: Simulating the anharmonic and quantum ionic motion

The atomic motion controls important properties of materials, such as thermal transport, phase transitions, and vibrational spectra. However, simulating the ionic dynamics is exceptionally challenging when quantum fluctuations are relevant (e.g., at low te ...

AMER PHYSICAL SOC2023

Numerical investigation of bound states in quantum magnets

Mithilesh Nayak

Bound-states of particles are an interesting problem in quantum mechanics dating back to 1931 Bethe's solution of spin-1/2 Heisenberg chain. These exotic composite states are realized in quantum magnets and are detectable in inelastic neutron scattering (I ...

EPFL2023

Spinon-like excitations in spin-1/2 quantum antiferromagnets

Irina Safiulina

Quantum magnetism remains a hot topic in condensed matter physics due to its complexity and possible powerful and significant applications in data storage and memory. To understand how the materials can achieve these goals, one should have a clear idea abo ...

EPFL2022

Hamiltonian reconstruction as metric for variational studies

Giuseppe Carleo

Variational approaches are among the most powerful techniques to approximately solve quantum many-body problems. These encompass both variational states based on tensor or neural networks, and parameterized quantum circuits in variational quantum eigensolv ...

2022

Local excitations in amorphous solids

Wencheng Ji

Amorphous solids are structurally disordered. They are very common and include glasses, colloids, and granular materials, but are far less understood than crystalline solids. Key aspects of these materials are controlled by the presence of excitations in w ...

EPFL2021

Quantum spin-liquid states in an organic magnetic layer and molecular rotor hybrid

László Forró, Bálint Náfrádi, Andrea Pisoni, Péter Szirmai, Edoardo Martino, Konstantins Mantulnikovs

The exotic properties of quantum spin liquids (QSLs) have continually been of interest since Anderson's 1973 ground-breaking idea. Geometrical frustration, quantum fluctuations, and low dimensionality are the most often evoked material's characteristics th ...

National Academy of Sciences2020

Ferrimagnetic 120 degrees magnetic structure in Cu2OSO4

Henrik Moodysson Rønnow, Arnaud Magrez, Ivica Zivkovic, Helmuth Berger, Nicola Casati, Lin Yang, Gregory Scott Tucker, Virgile Yves Favre, Romain Sibille

We report magnetic properties of a 3d(9) (Cu2+) magnetic insulator Cu2OSO4 measured on both powder and single crystal. The magnetic atoms of this compound form layers whose geometry can be described either as a system of chains coupled through dimers or as ...

AMER PHYSICAL SOC2020

Exact diagonalization study of the Hubbard-parametrized four-spin ring exchange model on a square lattice

Henrik Moodysson Rønnow, Noore Elahi Shaik, Sofie Janas

We have used exact numerical diagonalization to study the excitation spectrum and the dynamic spin correlations in the s = 1/2 next-next-nearest-neighbor Heisenberg antiferromagnet on the square lattice, with additional four-spin ring exchange from higher- ...

AMER PHYSICAL SOC2019

Floquet dynamics in the quantum measurement of mechanical motion

Tobias Kippenberg, Nicolas Piro Mastracchio, Liu Qiu, Itay Shomroni, Marie Adrienne Ioannou

The radiation-pressure interaction between one or more laser fields and a mechanical oscillator gives rise to a wide range of phenomena: From sideband cooling and backaction-evading measurements to ponderomotive and mechanical squeezing to entanglement and ...

2019

Building a Casimir metrology platform with a commercial MEMS sensor

Matthias Imboden

The Casimir Effect is a physical manifestation of quantum fluctuations of the electromagnetic vacuum. When two metal plates are placed close together, typically much less than a micron, the long wavelength modes between them are frozen out, giving rise to ...

Springer2019

Hydrogen Diffusion and Trapping in α-Iron: The Role of Quantum and Anharmonic Fluctuations

Michele Ceriotti, Bingqing Cheng

We investigate the thermodynamics and kinetics of a hydrogen interstitial in magnetic α-iron, taking account of the quantum fluctuations of the proton as well as the anharmonicities of lattice vibrations and hydrogen hopping. We show that the diffusivity o ...

2018

Gravity, scale invariance and the hierarchy problem

Mikhail Chapochnikov, Andrey Shkerin

Combining the quantum scale invariance with the absence of new degrees of freedom above the electroweak scale leads to stability of the latter against perturbative quantum corrections. Nevertheless, the hierarchy between the weak and the Planck scales rema ...

Springer Nature2018

Development of a monolithic near-field optomechanical system

Ryan Daniel Schilling

In the same year as Einstein's annus mirabilis, English engineer and physicist John Flemming patented the first rectifying diode, which he called the "Flemming valve". Einstein's work on the photoelectric effect would change our understanding of the nature ...

EPFL2018

Linear flavor-wave theory for fully antisymmetric SU( N ) irreducible representations

Frédéric Mila, Pierre Marcel Nataf, Francisco Hyunkyu Kim, Karlo Penc

The extension of the linear flavor-wave theory to fully antisymmetric irreducible representations (irreps) of SU(N) is presented in order to investigate the color order of SU(N) antiferromagnetic Heisenberg models in several two-dimensional geometries. The ...

2017

Probing Entangled States of the Nuclear-Electronic Quantum Magnet LiHoF₄

Ivan Kovacevic

Two objects are entangled when their quantum mechanical wavefunctions cannot be written in a separable product form. Entangling dissimilar quantum objects, or hybridization, has been suggested as a promising route to efficient quantum information processor ...

EPFL2016

The Higgs boson and cosmology

Mikhail Chapochnikov

I will discuss how the Higgs field of the Standard Model may have played an important role in cosmology, leading to the homogeneity, isotropy and flatness of the Universe; producing the quantum fluctuations that seed structure formation; triggering the rad ...

Royal Soc2015

The Role of Quantum Effects on Structural and Electronic Fluctuations in Neat and Charged Water

Michele Ceriotti, Federico Giberti, Michele Parrinello

In this work, we revisit the role of nuclear quantum effects on the structural and electronic properties of the excess proton in bulk liquid water using advanced molecular dynamics techniques. The hydronium ion is known to be a weak acceptor of a hydrogen ...

Amer Chemical Soc2014

Emergence and Detection of Exotic Phases in Spin-1 Systems

Frédéric Alexis Michaud

This work is devoted to the study of spin S = 1 systems, and more precisely to the emergence of exotic quantum phases in such systems, and to the establishment of tools to observe such phases. It is split in four main chapters. In the first chapter, we sho ...

EPFL2013

Evidence for Columnar Order in the Fully Frustrated Transverse Field Ising Model on the Square Lattice

Frédéric Mila, Tommaso Coletta, Sandro Wenzel

Using extensive classical and quantum Monte Carlo simulations, we investigate the ground-state phase diagram of the fully frustrated transverse field Ising model on the square lattice. We show that pure columnar order develops in the low-field phase above ...

2012

Heisenberg uncertainty principle as a probe of entanglement entropy: Application to superradiant quantum phase transitions

Pierre Marcel Nataf

Quantum phase transitions are often embodied by the critical behavior of purely quantum quantities such as entanglement or quantum fluctuations. In critical regions, we underline a general scaling relation between the entanglement entropy and one of the mo ...

Amer Physical Soc2012