Dresden 2014 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 37: Posters: Plasmonics, Electronic Structure and Spin-Orbit Interaction, Semiconductor and Insulator Surfaces, Nanostructures
O 37.95: Poster
Dienstag, 1. April 2014, 18:30–22:00, P2
Structural Transition in Atomic Chains Driven by Transient Doping — •Stefan Polei1, Paul Snijders2, Steve Erwin3, Franz Himpsel4, Karl-Heinz Meiwes-Broer1, and Ingo Barke1 — 1Department of Physics, University of Rostock, D-18051 Rostock, Germany — 2Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA — 3Center for Computational Materials Science, Naval Research Laboratory, Washington, DC 20375, USA — 4Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
Transient, non-equilibrium electronic phases are of great interest for various fields of physics, as they open the door to hidden states of matter that are not accessible by static measurements. In this contribution we present scanning tunneling microscopy (STM) measurements of a reversible structural transition on Si(553)-Au from a 1x3 ground state to a 1x2 excited state upon electron injection from the tip to the surface [1]. It is shown that the 1x2 phase is created by temporary doping of the atom chains. Random telegraph fluctuations between two levels of the tunneling current provide direct access to the dynamics of the phase transition. An intriguing observation is the unusual temperature behavior that results in easier excitation at lower temperatures. As a consequence, the 1x3 ground state is not accessible by STM at low temperatures (e.g. T=5K). In a broader context this implies that a phase observed using STM at the lowest possible temperatures may not be the ground state of the system.
[1] Polei et al., PRL 111, 156801 (2013)