Berlin 2024 – scientific programme

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O: Fachverband Oberflächenphysik

O 95: Electronic Structure of Surfaces II: Spectroscopy, Surface States

O 95.10: Talk

Thursday, March 21, 2024, 17:15–17:30, MA 144

Insights into the dominant confinement mechanism and a spatially inhomogeneous broadening effect in quantum corrals — •Marco Weiss, Michael Schelchshorn, Fabian Stilp, Alfred J. Weymouth, and Franz J. Giessibl — Institute of Experimental and Applied Physics, University of Regensburg, Universitätsstraße 31, 93053 Regensburg

Understanding the factors influencing the lifetime of electronic states in artificial quantum structures is of great significance for advancing quantum technologies. This study focuses on CO-based quantum corrals on a Cu(111) surface. Tunneling spectroscopy measurements revealed a strong correlation between the size of the quantum corral and spectral width, characterized by a predominant Gaussian line shape. We attribute this dominant Gaussian-shaped lifetime broadening to the interaction of surface state electrons with the corral boundary.

To further investigate this phenomenon, we constructed corrals of the same size but varying wall densities. Our findings indicate that the energetic behavior of resonant eigenstates in a quantum corral is predominantly dictated by elastic processes, such as tunneling, rather than lossy interactions with the wall, like bulk coupling or inelastic scattering.

Due to our characterization of the interaction between resonant electrons states and their confining boundary, the observations made in our work enhance the understanding of lifetime limiting factors in artificial quantum structures, paving the way for more predictive simulations and more controllable quantum systems.

Keywords: quantum corral; surface state; tunneling spectroscopy; lifetime; resonant electronic states