Nanoscale magnetic imaging of chemically modulated FeCo nanowires

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Using the data sample of 2.7×109 ψ(3686) events collected with the BESIII detector at the BEPCII collider, we present an observation of the Ξ(1530)0 polarization in the decay ψ(3686)→Ξ(1530)0Ξ¯(1530)0 with a significance larger than 20σ compared with all other tested hypotheses. The helicity amplitudes for the process ψ(3686)→Ξ(1530)0Ξ¯(1530)0 and the moduli of form factors including electric charge, magnetic dipole, electric quadrupole, and magnetic octupole are measured for the first time by performing an

Pixelated differential phase contrast (DPC) is a four-dimensional scanning transmission electron microscopy (4D-STEM) technique in which the position of the transmitted beam is tracked to reconstruct the electromagnetic fields of a sample. Although it can provide (semi-) quantitative information for a range of different applications, the measurements are greatly affected by the microscope's optical and acquisition settings in terms of sensitivity, accuracy, and spatial resolution, particularly when measurin

Multilayered synthetic antiferromagnets (SAFs) are artificial three-dimensional (3D) architectures engineered to create novel, complex, and stable spin textures. Noninvasive and quantitative nanoscale magnetic imaging of the two-dimensional stray field profile at the sample surface is essential for understanding the fundamental properties of the spin-structure and being able to tailor them to achieve new functionalities. However, the deterministic detection of spin textures and their quantitative characteri

Spin-wave excitations are fundamental to understanding the behavior of magnetic materials and hold promise for future information and communication technologies. Yet, modeling these accurately in transition-metal compounds remains challenging, starting from the self-interaction errors affecting localized and partially filled d orbitals in density-functional theory (DFT) with (semi)local functionals. In this work, we compare three advanced first-principles approaches for computing magnetic exchange parameter

Quantum computers promise to revolutionise our approach to complex calculations by leveraging the unique properties of their fundamental information units: the qubits. Features such as superposition and entanglement - absent in classical computing - enable an exponential increase in processing power, unlocking faithful simulations of natural phenomena and faster solutions to combinatorial problems. However, engineering a physical system capable of storing fragile quantum information while allowing for preci

The first observations of ion cyclotron emission (ICE) in the TCV tokamak are reported. The measured ICE frequency closely follows the deuterium ion cyclotron frequency at the magnetic axis, with temporal variations consistent with equilibrium evolution and associated shifts of the magnetic axis. Core ICE is observed primarily during phases with combined electron cyclotron resonance heating (ECRH) and neutral beam injection (NBI). In most discharges the second harmonic dominates, while in others higher harm

We present a recent upgrade of the incoherent Thomson scattering (TS) diagnostic for the Resonant Antenna Ion Device (RAID), a linear plasma source based on helicon excitation operated at the Swiss Plasma Center at Ecole Polytechnique Fédérale de Lausanne. By operating in the visible range, which facilitates the recording of the spectrally resolved TS signal with a gated camera, this system has greatly enhanced the ability to characterize the plasmas generated by RAID in argon, helium, deuterium, and hydrog

Nonlinear 3D magnetohydrodynamic (MHD) modeling of shattered pellet injection (SPI) in JET tokamak plasmas is performed with the JOREK code. The study focuses on the validation of simulation result with respect to experimental observations, addressing in particular figures of merit for the efficiency of the SPI, as a technique to mitigate thermal loads by injecting radiative impurities like neon during the thermal quench (TQ) phase of disruptions. A set of JET pulses with neon/deuterium atomic mixture ratio

The Fast Ion Loss Detector (FILD), installed on TCV in 2020 was redesigned and upgraded several times throughout this PhD. The collimator apertures were reduced to increase the energy resolution, a faster CMOS camera was intalled, a novel fast camera (up to 4 MHz) was installed to access microsecond velocity-space mapping, two more slits were added on the bottom partof the FILD head accessing to all magnetic field configurations, a bandpass optical filter was installed to reduce residual light contamination

The recently developed van der Waals magnets provide a promising platform for spintronics and magnonics. Here, we report the observation of surface magnon propagation in the van der Waals antiferromagnet CrSBr. We find a nearly unidirectional propagation of antiferromagnetic magnon modes, which emerge near the anticrossing of the optical and acoustic magnon bands, in agreement with our theory of magnetostatic waves in antiferromagnets. The propagation direction can be reversed by switching the magnetic fiel

Sample preparation remains a bottleneck for protein structure determination by cryo-electron microscopy. A frequently encountered issue is that proteins adsorb to the air–water interface of the sample in a limited number of orientations. This makes it challenging to obtain high-resolution reconstructions, or may even cause projects to fail altogether. We have previously observed that laser flash melting and revitrification of cryo-EM samples reduces preferred orientation for large, symmetric particles. Here

Strong electron correlations drive Mott insulator transitions. Yet, there exists no framework to classify Mott insulators by their degree of correlation. Cuprate superconductors, with their tunable doping and rich phase diagrams, offer a unique platform to investigate the evolution of these interactions. However, spectroscopic access to a clean half-filled Mott-insulating state is lacking in compounds with the highest superconducting onset temperature. To fill this gap, we introduce a pristine, half-filled

Transition metal dichalcogenides (TMDs) are semiconductor Van der Waals materials that can be obtained as stable monolayers (ML), characterized by bandgap values from visible to near infrared range. With decreasing thickness from bulk to MLs, TMDs show a transition from indirect to direct bandgap, which combined to strong exciton binding energies makes them propitious for optoelectronic applications. Their atomically flat, dangling bond free surfaces and weak interlayer van der Waals bonding enable stable e

In fundamental interactions research, dipolar magnets are particularly interesting to study since they provide a large spectrum of quantum phenomena [1-2]. Magnetic dipolar interaction are omnipresent in magnetic systems. However, in most of materials, various exchange interactions within the crystal environment hide the purely dipolar interaction. It has been shown [2-3] that in LiRF4 family, where R is a rare earth element the exchange interactions with nearest neighbours can be neglected. Moreover, by si

Recently, hybrid organic-inorganic metal halide perovskites have gained prominence as potent light harvesters in thin film solid-state photovoltaics. In particular the solar-to-electric power conversion efficiency (PCE) of devices using CH3NH3PbI3 as sensitizer has increased from 3 to 20.1% within only a few years. This key material can be prepared by solution processing from PbI2 and CH3NH3I in one step or by sequential deposition. In the latter case an electron capturing support such as TiO2 is first cove

Depending on the materials and processing parameters, composite materials consisting of an insulating matrix and a conductive filler may be electrically insulating, resistive or conducting. Previously, we had manufactured composites consisting of a resin and a conducting magnetic filler, and shown that polymerisation under magnetic field could achieve oriented conductors, with essentially unidirectional electrical conduction. In this work, we explore the possibility of replacing the resin matrix by a thermo

We present a theory stating how to overcome the classical Rayleigh-resolution limit. It is based upon a new resolution criterion in phase of coherent imaging process and its spatial resolution is thought to be only SNR limited. Recently, the experimental observation of systematically occurring phase singularities in coherent imaging of sub-Rayleigh distanced objects has been reported.1 The phase resolution criterion relies on the unique occurrence of phase singularities. A priori, coherent imaging system's

Combinatorial high-vacuum chemical vapor deposition (HV-CVD) was used to identify the conditions required to obtain hafnium-doped lithium niobate thin films on sapphire {001} substrates. Niobium tetraethoxydimethylaminoethoxide (Nb(OEt)(4)(dmae)), lithium tert-butoxide (Li(OBut)), and hafnium tert-butoxide (Hf(OBut)(4)) were used as precursors. X-ray diffraction (XRD) and transmission electron microscopy (TEM) indicated that a single phase of textured {001} Hf-doped lithium niobate film was obtained under c

The thermal conductivity κ of the iron-arsenide superconductor LiFeAs (Tc 18 K) was measured in single crystals at temperatures down to T50 mK and in magnetic fields up to H=17 T, very close to the upper critical field Hc218 T. For both directions of the heat current, parallel and perpendicular to the tetragonal c axis, a negligible residual linear term κ/T is found as T→0, showing that there are no zero-energy quasiparticles in the superconducting state. The increase in κ with magnetic field is the same fo

(001)-epitaxial SrTiO3 films were grown on (La, Sr)(Al, Ta)O-3 substrates for investigating the impact of biaxial strain on the antiferrodistortive (AFD) structural phase transition in SrTiO3. The films were fully constrained by the substrates, which resulted in the large in-plane compressive strain of -0.9%. The AFD transition temperature estimated using temperature controlled x-ray diffraction and transmission electron microscope was over 150K higher than the theoretical prediction, but rather supported t

Nanoscale magnetic imaging of chemically modulated FeCo nanowires

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Observation of Ξ (1530)0 Polarization and Determination of Its Electric and Magnetic Moments in ψ (3686) → Ξ (1530)0 Ξ ¯ (1530)0

Assessing the electric field sensitivity measured by pixelated differential phase contrast imaging in vacuum both in the absence of external fields and under field-bound conditions

Nanoscale NV-Center Magnetometry of a Synthetic Three-Dimensional Spin Texture

Comparative Study of Magnetic Exchange Parameters and Magnon Dispersions in Nio and Mno From First Principles

Spin Qubits in Germanium: Driving through Noise and Anisotropies

First observations of ion cyclotron emission in the TCV tokamak

High resolution incoherent Thomson scattering diagnostic for the Resonant Antenna Ion Device (RAID) helicon plasmas

Validation of 3d Mhd Simulations of Ne/d2 Mixed Shattered Pellet Injection in Jet

Study of the fast-ion confinement via velocity-space resolved measurements in several plasma scenarios in the TCV tokamak

Surface Magnon Propagation in a van der Waals Antiferromagnet

Laser flash melting cryo-EM samples to overcome preferred orientation

Magnetic Excitations of a Half-Filled Tl-based Cuprate

Engineering GaAs nanostructures for heterointegration with 2D transition metal dichalcogenides

High Resolution Fourier Transform Infrared Spectroscopy of the Quantum Magnet LiTmF4

Mesoscopic photosystems for solar light harvesting and conversion: facile and reversible transformation of metal-halide perovskites

Magnetically tuneable thermoplastic resistive composites

Beyond the lateral resolution limit by phase imaging

Combinatorial High-Vacuum Chemical Vapor Deposition of Textured Hafnium-Doped Lithium Niobate Thin Films on Sapphire

Isotropic three-dimensional gap in the iron arsenide superconductor LiFeAs from directional heat transport measurements

Antiferrodistortive Structural Phase Transition in Compressively-Strained Epitaxial SrTiO3 Film Grown on (La, Sr)(Al, Ta)O-3 Substrate