Quantum Effects in Atomic Nanofabrication Using Light Forces

Mathematisch-Naturwissenschaftliche Sektion, Fachbereich Physik

A.F. van Etteger, Erich Jurdik

R. Ohmukai, Shinji Urabe, Masayoshi Watanabe

Highly parallel and periodically narrow lines of ytterbium (Yb) atoms were successfully produced on a substrate using a near resonant laser light and direct-write atomic nanofabrication. Yb atoms are a promising material for nanofabrication using atom optics particularly due to their electric conductivity, the laser wavelength required for their manipulation, and the vapor pressure required for their fabrication. Collimated 174Yb atoms were channeled into the nodes of an optical standing wave with dipole force and then deposited onto a substrate. We clearly observed a grating pattern of Yb atoms fabricated on a substrate with a line separation of approximately 200 nm after examining the surface of the substrate with an atomic force microscope. This is the first demonstration of nanofabrication using the atom-optical approach with Yb atoms.

Jabez J. McClelland

Christina M. Spaegele, Mehdi Rezaee, Thomas Werkmeister +8 more

Overcoming the limitations of current nanofabrication techniques to achieve nanoscale feature sizes is essential for achieving new regimes of light-matter interactions at extreme frequencies and length scales. Here, we demonstrate a scalable nanofabrication platform capable of producing in-plane feature sizes down to 1.75 nm, pushing the boundaries of current top-down nanofabrication techniques. Using precise thickness control of atomic layer deposition (ALD) and employing widely spaced oxide nanofins, we transform conventional ALD into a surface structuring method that produces nanolaminates with sub-10 nm periodicities over large areas. The resulting nanostructures can be used as a one-dimensional gate array to control charge carriers in two-dimensional materials. As an initial demonstration, we integrate the platform with graphene and perform electron transport measurements. In the presence of the gate array enabled by the nanolaminate, we observe satellite Dirac peaks consistent with band-structure modulation, suggestive of quantum-confinement effects. Our platform paves the way for exploring previously inaccessible regimes of nanoscale light-matter interactions, holding significant promise for applications in short wavelength optics, electronics, and polaritonics.

Erich Jurdik

Fundamental interaction processes between atoms and photons are exploited to control external degrees of freedom of the atoms. Laser light, when properly tuned near an atomic resonance, exerts such forces that the atoms are repelled from or attracted to the regions with low light intensities. We use these forces to manipulate atom beams on nanometer-scale. In the simplest approach to nanofabrication via atom optics, a laser standing wave serves as a 'mask' through which the atoms are deposited onto a substrate. In this thesis we first present the modeling results on the focusing properties of a standing wave laser field and on the surface diffusion and growth phenomena in laser-focused atomic deposition. The development of our experimental facility for laser-manipulated deposition with chromium atoms (based on the obtained modeling results) is reported on. Thereafter, we demonstrate laser manipulation of chromium atoms and fabrication of nanostructures with these atoms. The results obtained in Nijmegen and also those obtained in collaboration with J.J. McClelland's group from the National Institute of Standards and Technology (Gaithersburg, Maryland, USA) are analyzed with the aim of understanding the role of atom-optical and surface growth phenomena in the fabrication process of laser-focused nanostructures