Publications associées à Physical pressure and chemical expansion effects on the skyrmion phase in Cu2OSeO3

Molecular intercalation in the van der Waals antiferromagnets FePS3 and NiPS3

Bruce Normand, Xiaoyu Xu, Sheng Xu, Ying Chen, Zeyu Wang, Shuo Li, Weiqiang Yu

We have performed electrochemical treatment of the van der Waals antiferromagnetic materials FePS3 and NiPS3 with the ionic liquid EMIM-BF4, achieving significant molecular intercalation. Mass analysis of the intercalated compounds, EMIMx-FePS3 and EMIMx-N ...

Amer Physical Soc2024

Field-controlled multicritical behavior and emergent universality in fully frustrated quantum magnets

Bruce Normand

Phase transitions in condensed matter are a source of exotic emergent properties. We study the fully frustrated bilayer Heisenberg antiferromagnet to demonstrate that an applied magnetic field creates a previously unknown emergent criticality. The quantum ...

Nature Portfolio2024

Frustrated magnets in the limit of infinite dimensions: Dynamics and disorder-free glass transition

Achille Mauri

We study the statistical mechanics and the equilibrium dynamics of a system of classical Heisenberg spins with frustrated interactions on a d -dimensional simple hypercubic lattice, in the limit of infinite dimensionality d -> infinity . In the analysis we ...

Amer Physical Soc2024

Magnetism of Single Surface Adsorbed Atoms Studied with Radio-Frequency STM

Clément Marie Soulard

This thesis investigates the magnetic properties of single atoms and molecules adsorbed on thin magnesium oxide decoupling layers, grown on a silver single crystal. To address these systems experimentally, we use a low temperature scanning tunneling micros ...

EPFL2024

The magnet feeders for the European DEMO fusion reactor: Conceptual design and recent advances

Rainer Wesche, Frédéric Michel, Roberto Guarino

The magnet feeders are part of the critical systems of a fusion reactor since they represent the interface between the in-cryostat components at 4.5 K and the room-temperature cryogenic plant and power supply. The European DEMO tokamak foresees 16 toroidal ...

2024

Computational fluid dynamics simulations of the heat transfer properties of graphene-based nanolubricants and application to hydrodynamic lubrication

Roberto Guarino

In this paper, we consider experimental data available for graphene-based nanolubricants to evaluate their convective heat transfer performance by means of computational fluid dynamics (CFD) simulations. Single-phase models with temperature-dependent prope ...

Aip Publishing2024

Towards Scalable Electronics: Synthetic 2D Materials for Large-Area 2D Circuit Integration

Zhenyu Wang

In the past decades, a significant increase of the transistor density on a chip has led to exponential growth in computational power driven by Moore's law. To overcome the bottleneck of traditional von-Neumann architecture in computational efficiency, effo ...

EPFL2024

Phase diagram of the J-Jd Heisenberg model on the maple leaf lattice: Neural networks and density matrix renormalization group

Ronny Thomale, Pratyay Ghosh

We microscopically analyze the nearest-neighbor Heisenberg model on the maple leaf lattice through neural quantum state (NQS) and infinite density matrix renormalization group (iDMRG) methods. Embarking to parameter regimes beyond the exact dimer singlet g ...

Amer Physical Soc2024

Local vs. cooperative: Unraveling glass transition mechanisms with SEER

Matthieu Wyart, Wencheng Ji

Which phenomenon slows down the dynamics in supercooled liquids and turns them into glasses is a long-standing question of condensed matter. Most popular theories posit that as the temperature decreases, many events must occur in a coordinated fashion on a ...

National Academy of Sciences2024

How Reproducible is the Synthesis of Zr-Porphyrin Metal-Organic Frameworks? An Interlaboratory Study

Jocelyn Richard Roth, Wendy Lee Queen, Rawan Al Natour

Metal-organic frameworks (MOFs) are a rapidly growing class of materials that offer great promise in various applications. However, the synthesis remains challenging: for example, a range of crystal structures can often be accessed from the same building b ...

Wiley-V C H Verlag Gmbh2024

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

Murunskite - a new class of functional material

Davor Tolj

The subject of the present work is discovery and in-depth characterization of a new class of functional materials. Tuning of the bond polarity and orbital occupation with a goal of establishing balance between localization and delocalization of electrons - ...

EPFL2023

Direct Observation of the Phase Transition in C60 Fullerene

Chengcheng Yan

In the third study, the order-disorder phase transition of single-crystal C60 is studied using time-resolved electron microscopy. Solid C60 undergoes a first-order phase transition upon heating to 260 K. This is a structural transition from the low-tempera ...

EPFL Infoscience2023

Unveiling new quantum phases in the Shastry-Sutherland compound SrCu2(BO3)(2) up to the saturation magnetic field

Frédéric Mila

Under magnetic fields, quantum magnets often undergo exotic phase transitions with various kinds of order. The discovery of a sequence of fractional magnetization plateaus in the Shastry-Sutherland compound SrCu2(BO3)(2) has played a central role in the hi ...

Nature Portfolio2023

Pressure-freezing of dodecane: exploring the crystal structures, formation kinetics and phase diagrams for colossal barocaloric effects in n-alkanes

Tomasz Poreba

Barocaloric (BC) materials provide cheaper and more energy efficient alternatives to traditional refrigerants. Some liquid alkanes were recently shown to exhibit a colossal BC effect, matching the entropy changes in commercial vapour-liquid refrigerants. D ...

Royal Soc Chemistry2023

Spin Textures in 2D Magnets

Lukas Powalla

The continuous reduction of the structural size in nanotechnology slowed down over the last decade, approaching the natural limit of single atoms as building blocks of matter. Therefore, intensive research is directed toward exploring new frontiers, in par ...

EPFL2023

Broadband spectroscopy and inelastic light scattering on the canted antiferromagnet hematite for antiferromagnetic magnonics

Mohammad Hamdi

Collective spin excitations propagating in magnetically ordered materials are called spin waves (SWs) or magnons. They are promising for low-power and beyond-CMOS information processing, which do not suffer from the ohmic losses. SWs in ferromagnets (antif ...

EPFL2023

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

Charge multipole correlations and order in Cs2TaCl6

Henrik Moodysson Rønnow, Ivica Zivkovic, Jana Pásztorová, Jian Rui Soh

We examine the role of charge, structural, and spin degrees of freedom in the previously poorly understood phase transition in the 5d1 transition-metal double perovskite Cs2TaCl6 using a combination of computational and experimental techniques. Our heat ca ...

AMER PHYSICAL SOC2023

The influence of the gas on the dynamics of cavitation bubbles

Davide Bernardo Preso

Cavitation bubbles, extensively investigated in fluid mechanics, present enduring challenges in hydraulic machinery, while holding considerable potential for practical applications in biomedicine and sonochemistry. Despite more than a century of research, ...

EPFL2023