Regensburg 2019 – wissenschaftliches Programm
MA 45.5: Vortrag
Donnerstag, 4. April 2019, 11:45–12:00, H15
Spin selective tunneling processes between Yu-Shiba-Rusinov states — •Haonan Huang1, Jacob Senkpiel1, Robert Drost1, Ciprian Padurariu2, Simon Dambach2, Björn Kubala2, Juan Carlos Cuevas3, Alfredo Levy Yeyati3, Joachim Ankerhold2, Christian R. Ast1, and Klaus Kern1,4 — 1MPI für Festkörperforschung, Stuttgart, Germany — 2Institut für komplexe Quantensysteme, Universität Ulm, Ulm, Germany — 3Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, Spain — 4EPFL, Switzerland
A Yu-Shiba-Rusinov (YSR) state is a pair of in-gap states resulting from the interaction of magnetic atoms with a superconductor. We are experimentally able to introduce any YSR state of desired energy position and peak heights to the apex of a superconducting vanadium STM tip, and then use this novel tip to characterize sample YSR defects to study spin selective tunneling. YSR-YSR tunneling happens resonantly when the bias voltage is at the sum of tip and sample YSR energies. If the temperature is finite, there is thermal occupation of the originally empty YSR state, which results in thermally assisted YSR-YSR tunneling that happens at the difference of tip and sample YSR energies. The relative spin orientation will change the intensity of both processes, and Green's function theory can readily explain the spin selection rules. We use a mK-STM to study the YSR-YSR tunneling processes from 15mK to 1K, and the temperature dependence of thermal and normal YSR-YSR processes gives insight of their spin dynamics.