Publications by Markus Etzkorn

Extracting transport channel transmissions in scanning tunneling microscopy using superconducting excess current

Klaus Kern, Markus Etzkorn, Jacob Senkpiel

Transport through quantum coherent conductors, such as atomic junctions, is described by conduction channels. Information about the number of channels and their transmissions can be extracted from various sources, such as multiple Andreev reflections, dyna ...

AMER PHYSICAL SOC2022

Gigahertz Frame Rate Imaging of Charge-Injection Dynamics in a Molecular Light Source

Klaus Kern, Markus Etzkorn, Anna Maria Roslawska, Abhishek Grewal

Light sources on the scale of single molecules can be addressed and characterized at their proper sub-nanometer scale by scanning tunneling microscopy-induced luminescence (STML). Such a source can be driven by defined short charge pulses while the lumines ...

AMER CHEMICAL SOC2021

Single channel Josephson effect in a high transmission atomic contact

Klaus Kern, Markus Etzkorn, Jacob Senkpiel

The Josephson effect in scanning tunneling microscopy (STM) is an excellent tool to probe the properties of a superconductor on a local scale. We use atomic manipulation in a low temperature STM to create mesoscopic single channel contacts and study the Jo ...

NATURE PUBLISHING GROUP2020

Robustness of Yu-Shiba-Rusinov resonances in the presence of a complex superconducting order parameter

Klaus Kern, Markus Etzkorn, Jacob Senkpiel

Robust quantum systems rely on having a protective environment with minimized relaxation channels. Super-conducting gaps play an important role in the design of such environments. The interaction of localized single spins with a conventional superconductor ...

AMER PHYSICAL SOC2019

Single Charge and Exciton Dynamics Probed by Molecular-Scale-Induced Electroluminescence

Klaus Kern, Markus Etzkorn, Christoph Grosse, Anna Maria Roslawska

American Chemical Society (ACS)2018

Giant apparent lattice distortions in STM images of corrugated sp2-hybridised monolayers

Laurent Claude, Harald Brune, Alfredo Pasquarello, François Patthey, Stefano Rusponi, Anne Lehnert, Quentin Dubout, Markus Etzkorn, Donat Fabian Natterer

We report on the strengths and limitations of scanning tunnelling microscopy (STM) when used for characterising atomic-scale features of quasi two-dimensional materials, such as graphene and single layers of hexagonal boron nitride, which may present stron ...

Institute of Physics (IoP) and Deutsche Physikalische Gesellschaft2016

Critical Josephson current in the dynamical Coulomb blockade regime

Klaus Kern, Markus Etzkorn, Maximilian Assig, Matthias Alexander Eltschka

The current-voltage characteristics of a voltage-biased Josephson junction in the low conductance regime of an ultra-low temperature scanning tunneling microscope (STM) is dominated by sequential charge tunneling. Using P(E) theory we show that the Josephs ...

Amer Physical Soc2016

A nanoscale gigahertz source realized with Josephson scanning tunneling microscopy

Klaus Kern, Markus Etzkorn, Maximilian Assig, Matthias Alexander Eltschka

Using the AC Josephson effect in the superconductor-vacuum-superconductor tunnel junction of a scanning tunneling microscope (STM), we demonstrate the generation of GHz radiation. With the macroscopic STM tip acting as a lambda/4-monopole antenna, we first ...

Amer Inst Physics2015

Superconducting scanning tunneling microscopy tips in a magnetic field: Geometry-controlled order of the phase transition

Klaus Kern, Markus Etzkorn, Maximilian Assig, Matthias Alexander Eltschka

The properties of geometrically confined superconductors significantly differ from their bulk counterparts. Here, we demonstrate the geometrical impact for superconducting scanning tunneling microscopy (STM) tips, where the confinement ranges from the atom ...

Amer Inst Physics2015

Probing Absolute Spin Polarization at the Nanoscale

Klaus Kern, Markus Etzkorn, Maximilian Assig, Matthias Alexander Eltschka

Probing absolute values of spin polarization at the nanoscale offers insight into the fundamental mechanisms of spin-dependent transport. Employing the Zeeman splitting in superconducting tips (Meservey-Tedrow-Fulde effect), we introduce a novel spin-polar ...

Amer Chemical Soc2014

Dynamic Control of Plasmon Generation by an Individual Quantum System

Klaus Kern, Markus Etzkorn, Uta Schlickum, Romain Froidevaux, Alexander Kabakchiev, Theresa Lutz, Christoph Grosse

Controlling light on the nanoscale in a similar way as electric currents has the potential to revolutionize the exchange and processing of information. Although light can be guided on this scale by coupling it to plasmons, that is, collective electron osci ...

Amer Chemical Soc2014

A 10 mK scanning tunneling microscope operating in ultra high vacuum and high magnetic fields

Klaus Kern, Markus Etzkorn, Maximilian Assig

We present design and performance of a scanning tunneling microscope (STM) that operates at temperatures down to 10 mK providing ultimate energy resolution on the atomic scale. The STM is attached to a dilution refrigerator with direct access to an ultra h ...

Amer Inst Physics2013

Quantitative mapping of fast voltage pulses in tunnel junctions by plasmonic luminescence

Klaus Kern, Markus Etzkorn, Christoph Grosse

An optical read-out technique is demonstrated that enables mapping the time-dependent electrostatic potential in the tunnel junction of a scanning tunneling microscope with millivolt and nanosecond accuracy. We measure the time-dependent intensity of plasm ...

Amer Inst Physics2013

Combined ARPES and STM study of Pb/Au(111) Moiré structure: One overlayer, two symmetries

Harald Brune, Klaus Kern, Marco Grioni, Markus Etzkorn, Emmanouil Frantzeskakis, Alberto Crepaldi

The structural and electronic properties of a Pb monolayer (ML) grown on Au(111) are investigated by scanning tunneling microscopy (STM) and angle resolved photoelectron spectroscopy (ARPES). We find an incommensurate Moire structure with an approximate (5 ...

Amer Physical Soc2013

Magnetocrystalline anisotropy energy of Co and Fe adatoms on the (111) surfaces of Pd and Rh

Harald Brune, Pietro Gambardella, Stefano Rusponi, Anne Lehnert, Géraud Moulas, Markus Etzkorn

We performed a combined theoretical and experimental investigation of the orbital magnetism and magnetocrystalline anisotropy of isolated Co and Fe adatoms on Pd(111) and Rh(111). Theoretical calculations of the spin and orbital moments are based on ab ini ...

2010

Measurement of Fast Electron Spin Relaxation Times with Atomic Resolution

Markus Etzkorn

Single spins in solid-state systems are often considered prime candidates for the storage of quantum information, and their interaction with the environment the main limiting factor for the realization of such schemes. The lifetime of an excited spin state ...

American Association for the Advancement of Science2010

Magnetic anisotropy of Fe and Co adatoms and Fe clusters magnetically decoupled from Ni_{3}Al(111) by an alumina bilayer

Harald Brune, Stefano Rusponi, Anne Lehnert, Markus Etzkorn

The magnetic properties of individual Fe and Co atoms as well as of small Fe clusters adsorbed on two atomic layers of Al2O3 grown on Ni3Al(111) have been investigated by x-ray absorption spectroscopy and x-ray magnetic circular dichroism. We find ratios o ...

2010

High magnetic moments and anisotropies for FexCo1 - x monolayers on Pt(111)

Harald Brune, Pietro Gambardella, Stefano Rusponi, Anne Lehnert, Géraud Moulas, Markus Etzkorn

2008