suspended CVD graphene
semiconducting nanowire
spininjection into graphene
...based on a semiconducting nanowire
device made from NbTiN
for circuit QED
Editors’ Suggestion Simon Zihlmann et al. “Nonequilibrium properties of graphene probed by superconducting tunnel spectroscopy”, Phys. Rev. B 99, 075419 (2019) In a conductor the current is carried by electrons. In a macroscopic conductor, the charge distribution is in local equilibrium,
Wideband and On-Chip Excitation for Dynamical Spin Injection into Graphene Graphene is an ideal material for spin transport, as very long spin-relaxation times and lengths can be achieved even at room temperature. However, electrical spin injection is challenging due to
Simon Zihlmann successfully defended his PhD thesis “Spin and charge relaxation in graphene” on Friday 13th of April. We welcomed Prof. Dr. Bart J. van Wees (Univ. Groningen) and Porf. Dr. Christoph Stampfer (Univ. Aachen) as external PhD committee members.
We have always been open to side-projects leading to applications. One was CNT reinforced composites where we have written an influential patent. The other is the exploration of ion-sensitive field-effect transistors for biochemical sensing. Though there was a substantial literature,
We have demonstrated efficient spin-injection into graphene using h-BN as tunneling barrier. We have used CVD-grown h-BN on CVD graphene, as well as few layer h-BN on a graphene h-BN stack. We have also looked into tunneling barriers made from
Ferromagnetic contacts can induce an exchange field into a nanodevice, but can also be used as a source of spin-polarized electrons and detector. In the latter case, so called tunneling magneto-resistance (TMR) devices are obtained when at least two contacts
We were one of the first group (if not the first) looking into QDs that are coupled to superconductors (SCs).1 Our devices were realized with carbon nanotubes CNTs and semiconducting nanowires (SNWs). In our early studies we were intrigued by
In the framework of the ERC advanced research project QUEST, we have developed a versatile high-frequency setup that works in the frequency window 1-10 GHz and allows for high-resolution reflectance and noise measurements. In order to apply this to high
Our groups has been pioneering shot-noise measurements in nanodevices.1 We have studied noise in various geometries, in the single-electron tunneling device,2 in diffusive wires,3,4 in metallic S-N devices,5 in ballistic cavities6 and in quantum Hall devices where we could demonstrate
Bottom-up grown single-crystalline semiconducting nanowires (SNWs) are very versatile systems, since quantum dots can readily be defined using external finger gate electrodes. Due to the large g-factor and large spin-orbit interaction, SNWs are a hot topic today, since one-dimensional helical