Publications related to Thermal Evolution of Dirac Magnons in the Honeycomb Ferromagnet CrBr3

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

Exciton migration in two-dimensional materials

Excitons play an essential role in the optical response of two-dimensional materials. These are bound states showing up in the band gaps of many-body systems and are conceived as quasiparticles formed by an electron and a hole. By performing real-time simu ...

Nature Portfolio2024

Resonant Tip-Enhanced Raman Spectroscopy of a Single-Molecule Kondo System

Jiri Dolezal

Tip-enhanced Raman spectroscopy (TERS) under ultrahigh vacuum and cryogenic conditions enables exploration of the relations between the adsorption geometry, electronic state, and vibrational fingerprints of individual molecules. TERS capability of reflecti ...

Amer Chemical Soc2024

Magnon-phonon interactions enhance the gap at the Dirac point in the spin-wave spectra of CrI3 two-dimensional magnets

Iurii Timrov

Recent neutron-diffraction experiments in honeycomb CrI3 quasi-2D ferromagnets have evinced the existence of a gap at the Dirac point in their spin-wave spectra. The existence of this gap has been attributed to strong in-plane Dzyaloshinskii-Moriya or Kita ...

2023

Ultrafast control of emergent quantum matter probed by electron microscopy

Benoît Guilhem Michel Binh Truc

In the quest for controlling materials' properties, light as an external stimulus has a special place as it can create new states of matter and enable their ultrafast manipulation. In particular, spintronics, an exciting emergent field relying on the elect ...

EPFL2023

Structure, Spin Correlations, and Magnetism of the S=1/2 Square-Lattice Antiferromagnet Sr2CuTe1-xWxO6 (0 ≤ x ≤ 1)

Henrik Moodysson Rønnow, Peter Babkevich, Sami Juhani Vasala, Ellen Fogh

Quantum spin liquids are highly entangled magnetic states with exotic properties. The S = 1/2 square-lattice Heisenberg model is one of the foundational models in frustrated magnetism with a predicted, but never observed, quantum spin liquid state. Isostru ...

Amer Chemical Soc2023

Correlated insulator collapse due to quantum avalanche via in-gap ladder states

Xi Chen, Camille Didier Georges Aron

The significant discrepancy observed between the predicted and experimental switching fields in correlated insulators under a DC electric field far-from-equilibrium necessitates a reevaluation of current microscopic understanding. Here we show that an elec ...

Nature Portfolio2023

Magnetic excitations in the topological semimetal YbMnSb2

Jian Rui Soh

We report neutron scattering measurements on YbMnSb2 which shed light on the nature of the magnetic moments and their interaction with Dirac fermions. Using half-polarized neutron diffraction we measured the field-induced magnetization distribution in the ...

AMER PHYSICAL SOC2023

Many-body physics with strongly interacting fermions coupled to light

Victor Youri Helson

This thesis reports on the realization of the first experiments conducted with superfluid, strongly interacting Fermi gases of 6Li coupled to the light field of an optical cavity. In the scope of existing ultracold atomic platforms, this is the first time ...

EPFL2023

Linear and nonlinear magnetization dynamics in permalloy thin films grown on DNA origami and nanopatterned permalloy/YIG hybrid structures

Andrea Mucchietto

Spin waves (SWs) are collective excitations of the spin ensemble in systems with magnetic order. In quantum mechanics, a SW is known as a magnon, which is the quasiparticle describing the quantized nature of these wave-like excitations. Magnonics is the re ...

EPFL2023

Unconventional Flat Chern Bands and 2e Charges in Skyrmionic Moire Superlattices

Oleg Yazyev, Yifei Guan

The interplay of topological characteristics in real space and reciprocal space can lead to the emergence of unconventional topological phases. In this Letter, we implement a novel mechanism for generating higher-Chern flat bands on the basis of twisted bi ...

AMER CHEMICAL SOC2023

Investigation of Electro-Nuclear Spin States in LiHoF4 Using Cavity-Magnon-Polariton Technique

Yikai Yang

LiReF

_4

("Re" stands for the rare-earth element) and their doped derivatives have long been recognized as a family of compounds that exhibit rich phenomena in quantum magnetism, drawing wide attention to them from both fundamental researchers and industr ...

EPFL2023

Twisted chiral superconductivity in photodoped frustrated Mott insulators

Philipp Georg Werner Seeberger, Markus Müller, Jiajun Li

Recent advances in ultrafast pump-probe spectroscopy provide access to hidden phases of correlated matter, including light-induced superconducting states. The theoretical understanding of these nonequilibrium phases remains limited, particularly for correl ...

AMER PHYSICAL SOC2023

Density-wave ordering in a unitary Fermi gas with photon-mediated interactions

Jean-Philippe Brantut, Victor Youri Helson, Kevin Etienne Robert Roux, Hideki Konishi, Timo Zwettler, Elvia Colella

A density wave (DW) is a fundamental type of long-range order in quantum matter tied to self-organization into a crystalline structure. The interplay of DW order with superfluidity can lead to complex scenarios that pose a great challenge to theoretical an ...

NATURE PORTFOLIO2023

Seeding and Emergence of Composite Skyrmions in a van der Waals Magnet

Klaus Kern, Marko Burghard, Lukas Powalla

Topological charge plays a significant role in a range of physical systems. In particular, observations of real-space topological objects in magnetic materials have been largely limited to skyrmions - states with a unitary topological charge. Recently, mor ...

Wiley-V C H Verlag Gmbh2023

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

Machine-learning the electronic density of states: electronic properties without quantum mechanics

Chiheb Ben Mahmoud

The electronic density of states (DOS) quantifies the distribution of the energy levels that can be occupied by electrons in a quasiparticle picture and is central to modern electronic structure theory. It also underpins the computation and interpretation ...

EPFL2023

Topological Effects in Carbon-based Two-dimensional Nanostructures

Yifei Guan

Recent advances on low-dimensional and topological materials has greatly inspired the research in condensed matter physics. This thesis is devoted to the computational and theoretical study of topological effects in two-dimensional materials, especially na ...

EPFL2023

Real space and reciprocal space investigations of the spin dynamics in skyrmion-hosting materials

Le Yu

Magnetic skyrmions are whirl-like spin configurations with particle-like properties protected by non-trivial topology. Due to their unique spin structures and dynamical properties, they have attracted tremendous interests over the past decade, from fundame ...

EPFL2022

Cavity Quantum Electrodynamics with strongly correlated fermions

Kevin Etienne Robert Roux

This thesis presents the first cavity quantum electrodynamics experiments performed with a degenerate gas of

^6

Li with strong atom-atom interactions. The first part of this manuscript describes the design and the building of the apparatus that has been e ...

EPFL2022