Lateral quantum wells at vicinal Au(111) studied with angle-resolved photoemission

Electrons at noble metal surfaces can be confined within terraces leading to one-dimensional surface states. These can be studied with angle-resolved photoemission from vicinal surfaces with regular arrays of (111)-oriented terraces. Here we show the case of Au(23 23 21), which is vicinal to Au(111) and displays L=56 Angstrom wide terraces. The surface state band appears broken up into three quantum well levels that match to those of the infinite quantum well of the same width L. Their parallel momentum dependent photoemission intensity allows mapping the probability density of the confined wave function in reciprocal space using angle-resolved photoemission. By Fourier transformation, their respective experimental wave functions in real space are obtained and compared to the case of the infinite quantum-well, showing excellent agreement. Final state step superlattice diffraction effects have also been observed. Finally, we observe the quenching of the characteristic spin-orbit coupling of Au(111) in the confinement direction. This is another indication of the one-dimensional character of the surface state, as confirmed with first order perturbation theory

Statement in Support of: “Virology under the Microscope—a Call for Rational Discourse”

[Extract] We, members of the Australasian Virology Society, agree with and support the statement entitled “Virology under the Microscope—a Call for Rational Discourse” (1). Like virologists everywhere, we have worked with scientist and clinician colleagues worldwide to develop knowledge, tests, and interventions which collectively have reduced the number of deaths due to COVID-19 and curtailed its economic impact. Such work adds to the extraordinary achievements resulting from virology research that have delivered vaccines and/or antivirals against a long list of diseases and global scourges, including AIDS, smallpox, and polio (1). We believe the question of the origin of SARS-CoV-2 should be approached with an open mind and in consideration of the best scientific evidence available. We concur with the view that the zoonosis hypothesis has the strongest supporting evidence (2–4), and this is a scenario that has been observed repeatedly in the past (5), including in Australia (6). Recent data strongly support the zoonosis hypothesis (7). We share the concern that emotive and fear-based dialogues in this area add to public confusion and can lead to ill-informed condemnation of virology research