Publications de Matthias Alexander Eltschka

Critical Josephson current in the dynamical Coulomb blockade regime

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

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, Matthias Alexander Eltschka, Maximilian Assig

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, Matthias Alexander Eltschka, Maximilian Assig

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

Scanning Tunneling Microscopy using Superconducting Tips to Probe Absolute Spin Polarization

Matthias Alexander Eltschka

The interplay of superconductivity and magnetism is investigated for systems with dimensions ranging from the mesoscopic to the atomic scale by scanning tunneling microscopy (STM) at millikelvin temperatures and by numerical calculations. Based on geometri ...

EPFL2015

Probing Absolute Spin Polarization at the Nanoscale

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

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

Nonadiabatic Spin Torque Investigated Using Thermally Activated Magnetic Domain Wall Dynamics

Matthias Alexander Eltschka

Using transmission electron microscopy, we investigate the thermally activated motion of domain walls (DWs) between two positions in Permalloy (Ni80Fe20) nanowires at room temperature. We show that this purely thermal motion is well described by an Arrheni ...

2010