Publications related to Inelastic scattering

Spin wave spectra of single crystal CoPS3

Henrik Moodysson Rønnow, Luc Testa, Ursula Bengaard Hansen, Mechthild Enderle

The spin waves in single crystals of the layered van der Waals antiferromagnet CoPS3 have been measured using inelastic neutron scattering. The data show four distinct spin wave branches with large (>14 meV) energy gaps at the Brillouin zone center indicat ...

2023

Quantum state-resolved methane scattering from Ni(111) and NiO(111) by bolometer infrared laser tagging: The effect of surface oxidation

Rainer Beck, Christopher Scott Reilly, Bo-Jung Chen, Patrick Floss

We describe a novel UHV state-to-state molecule/surface scattering apparatus with quan- tum state preparation of the incident molecular beam and angle-resolved quantum state detection of the scattered molecules. State resolved detection is accomplished usi ...

2023

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

Lack of Out-of-Plane Dispersion of the Magnetic Excitations of Charge-Stripe Ordered La2−xSrxNiO4+δ

Paul Gregory Freeman, Alexandra Angeline Turrini

The dependence of the magnetic excitations in the out-of-NiO-plane direction of charge stripe ordered La2-xSrxNiO4+delta x = 0.3 and delta = 0.11 +/- 0.01 were investigated by inelastic neutron scattering. No dispersion was observed for the magnetic excita ...

Physical Soc Japan2022

State-to-state surface scattering of methane studied by bolometric infrared laser tagging detection

Bo-Jung Chen

State-to-state molecule/surface scattering experiments prepare the incident molecules in a specific quantum state and measure the quantum state distribution of the scattered molecules. The comparison of state resolved experiments with theory can serve as s ...

EPFL2022

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

Ultrafast Transverse Modulation of Free Electrons by Interaction with Shaped Optical Fields

Fabrizio Carbone, Ivan Madan, Alexey Sapozhnik, Thomas La Grange, Phoebe Marie Tengdin, Giovanni Maria Vanacore, Ido Kaminer, Simone Gargiulo, Francesco Barantani, Veronica Leccese

Spatiotemporal electron-beam shaping is a bold frontier of electron microscopy. Over the past decade, shaping methods evolved from static phase plates to low-speed electrostatic and magnetostatic displays. Recently, a swift change of paradigm utilizing lig ...

AMER CHEMICAL SOC2022

Atom-surface van der Waals potentials of topological insulators and semimetals from scattering measurements

Davide Campi

The phenomenology of resonant scattering has been known since the earliest experiments upon scattering of atomic beams from surfaces and is a means of obtaining experimental information about the fundamentals of weak adsorption systems in the van der Waals ...

2021

Vibrationally inelastic scattering of HCl from Ag(111)

Jan Daniel Geweke

Using molecular beam cooled samples and quantum state-selective detection, we observe v = 0 -> 1 vibrational transitions when HCl (v = 0) collides with an Ag(111) surface and derive both the incidence energy and surface temperature dependence of the transi ...

AMER INST PHYSICS2020

Unraveling intrinsic correlation effects with angle-resolved photoemission spectroscopy

Marco Vanzini, Vladimir N. Strocov

Interaction effects can change materials properties in intriguing ways, and they have, in general, a huge impact on electronic spectra. In particular, satellites in photoemission spectra are pure many-body effects, and their study is of increasing interest ...

National Academy of Sciences2020

State-to-state methane-surface scattering as a probe of catalytic activity

Rainer Beck, Maarten Eduard van Reijzen, Bo-Jung Chen, Jörn Werdecker

Quantum state-resolved scattering experiments for methane molecules colliding with a catalytically active nickel surface are compared to scattering from a nickel surface passivated by a single layer of graphene. The vibrational state distribution of the sc ...

2020

Magnetic-Field-Induced Bound States in Spin-1/2 Ladders

Frédéric Mila, Mithilesh Nayak

Motivated by the recently observed intriguing mode splittings in a magnetic field with inelastic neutron scattering in the spin ladder compound (C5H12N)(2) CuBr4 (BPCB), we investigate the nature of the spin ladder excitations using a density matrix renorm ...

2020

Differential steric effects in the inelastic scattering of NO(X) plus Ar: spin-orbit changing transitions

Sean Dennis Steven Gordon

Spin-orbit changing transitions for bond-axis oriented collisions of NO(X) with Ar have been investigated with full quantum state selection via a crossed molecular beam experiment at collision energies of 532 cm(-1) and 651 cm(-1). NO(X) molecules were sel ...

2019

Soft-phonon driven hexagonal-orthorhombic phase transition in BaVS3

Helmuth Berger

The lattice dynamics of low-dimensional BaVS3 is reported across the hexagonal-orthorhombic phase transition occurring at T-S = 250 K using a combination of the thermal diffuse scattering of x rays, inelastic x-ray scattering, and density functional theory ...

2019

Time Domain NIRS Optode based on Null/Small Source-Detector Distance for Wearable Applications

Edoardo Charbon, Claudio Bruschini, Samuel Burri, Sreenil Saha

We present the designs of novel optode based probes integrating light detection and light-pulsing electronics in a single CMOS chip with functional blocks such as a fast pulse-laser driver and synchronized single-photon detection circuit, while exploiting ...

IEEE2019

Vibrational Energy Redistribution in a Gas-Surface Encounter: State-to-State Scattering of CH4 from Ni(111)

Rainer Beck, Jörn Werdecker, Maarten Eduard van Reijzen, Bo-Jung Chen

The fate of vibrational energy in the collision of methane (CH4) in its antisymmetric C-H stretch vibration (ν3) with a Ni(111) surface has been studied in a state-to-state scattering experiment. Laser excitation in the incident molecular beam prepared the ...

2018

New Insights into the Verwey Transition in Magnetite

Simone Borroni

Magnetite (Fe

_3

O

_4

) is the first magnetic material discovered by mankind. Despite thousands of years of applications, from the magnetic compass to data storage, and decades of basic research, it remains among the most fascinating materials for physicis ...

EPFL2018

Vibrationally and Rotationally Inelastic Scattering of Methane from Ni(111)

Jörn Werdecker

This thesis presents a quantum-state-resolved molecular beam study of the non-reactive scattering of methane (CH4) from a Ni(111) surface. It is one of the first experimental investigations in which the internal quantum state distribution of a polyatomic m ...

EPFL2018

Magnetic exchange parameters and anisotropy of the quasi-two-dimensional antiferromagnet NiPS3

Diane Virginie Marie Lançon

Neutron inelastic scattering has been used to measure the magnetic excitations in powdered NiPS3, a quasitwo-dimensional antiferromagnet with spin S = 1 on a honeycomb lattice. The spectra show clear, dispersive magnons with a similar to 7 meV gap at the B ...

AMER PHYSICAL SOC2018

Guest dynamics in methane hydrates and hydrogen hydrates under high pressure

Umbertoluca Ranieri

Hydrates of gas are non-stoichiometric inclusion compounds constituted of water and gas. Therein, the water molecules are hydrogen-bonded and form three-dimensional crystalline networks incorporating different kinds of polar or nonpolar guest gas molecules ...

EPFL2018