arXiv subjects

Sebastian Pedalino

Publications and source records attributed to Sebastian Pedalino.

4 recordsLinked to original sources

arXiv2026

Photoionization of temperature-controlled nanoparticles in a beam: Accurate and efficient determination of ionization energies and work functions

A beam of free alkali metal nanoparticles is produced by a condensation source, passed through a thermalizing tube adjustable over a broad temperature range, and ionized by tunable light. High stability of the particle flux and an automated data acquisition routine allow efficient collection of photoionization yield curves. A careful fit of the data to the universal Fowler function makes it possible to obtain nanoparticle ionization energies, and from those, the metal work functions, with $\sim$0.2% precision. The experimental arrangement, nanoparticle thermalization rates, and ionization threshold analysis are described in detail. The use of ultrapure and temperature-controlled gas-phase nanoparticles facilitates the analysis of electronic properties, such as work functions, and of their interplay with thermal lattice dynamics.

cond-mat.mes-hall↗

arXiv2025

Probing quantum mechanics using nanoparticle Schrödinger cats

The quantum superposition principle is a cornerstone of physics and at the heart of many quantum technologies. Yet, it is still often regarded counterintuitive because we do not observe its key features on the macroscopic scales of our daily lives. It is therefore intriguing to ask how quantum properties persist or change as we increase the size and complexity of objects. A paradigmatic test for this question can be realized by matter-wave interferometry, where the motion of individual massive particles becomes delocalized and needs to be described by a wave function that spans regions far larger than the particle itself. Here we present an experimental platform extending matter-wave interference to a qualitatively new class of materials that can vary widely in mass and size. We specifically demonstrate quantum interference of sodium nanoparticles, which can each contain more than 7'000 atoms at masses greater than 170'000 dalton. They propagate in a Schrödinger cat state with a macroscopicity of $μ$ = 15.5, surpassing all previous experiments by an order of magnitude and providing the most stringent exclusion limit for generic macrorealistic modifications of the Schrödinger equation to date.

quant-ph↗

arXiv2023

Experimental challenges for high-mass matter-wave interference with nanoparticles

We discuss recent advances towards matter-wave interference experiments with free beams of metallic and dielectric nanoparticles. They require a brilliant source, an efficient detection scheme and a coherent method to divide the de Broglie waves associated with these clusters: We describe an approach based on a magnetron sputtering source which ejects an intense cluster beam with a wide mass dispersion but a small velocity spread of 10%. The source is universal as it can be used with all conducting and many semiconducting or even insulating materials. Here we focus on metals and dielectrics with a low work function of the bulk and thus a low cluster ionization energy. This allows us to realize photoionization gratings as coherent matter-wave beam splitters and also to realize an efficient ionization detection scheme. These new methods are now combined in an upgraded Talbot-Lau interferometer with three 266 nm depletion gratings. We here describe the experimental boundary conditions and how to realize them in the lab. This next generation of near-field interferometers shall allow us to soon push the limits of matter-wave interference to masses up to 10 megadaltons.

quant-ph↗

arXiv2022

Nanoscale magnetism probed in a matter-wave interferometer

We explore a wide range of fundamental magnetic phenomena by measuring the dephasing of matter-wave interference fringes upon application of a variable magnetic gradient. The versatility of our interferometric Stern-Gerlach technique enables us to study alkali atoms, organic radicals and fullerenes in the same device, with magnetic moments ranging from a Bohr magneton to less than a nuclear magneton. We find evidence for magnetization of a supersonic beam of organic radicals and, most notably, observe a strong magnetic response of a thermal C$_{60}$ beam consistent with high-temperature atom-like deflection of rotational magnetic moments.

quant-ph↗