scientific publications

Theoretical, numerical, and experimental study of a flying qubit electronic interferometer

Tobias Bautze, Christoph Süssmeier, Shintaro Takada, Christoph Groth, Tristan Meunier, Michihisa Yamamoto, Seigo Tarucha, Xavier Waintal, Christopher Bäuerle

abstract: We discuss an electronic interferometer recently measured by Yamamoto et al. This “flying quantum bit” experiment showed quantum oscillations between electronic trajectories of two tunnel-coupled wires connected via an Aharanov-Bohm ring. We present a simple scattering model as well as a numerical microscopic model to describe this experiment. In addition, we present experimental data to which we confront our numerical results. While our analytical model provides basic concepts for designing the flying qubit device, we find that our numerical simulations allow us to reproduce detailed features of the transport measurements such as in-phase and antiphase oscillations of the two output currents as well as a smooth phase shift when sweeping a side gate. Furthermore, we find remarkable resemblance for the magnetoconductance oscillations in both conductance and visibility between simulations and experiments within a specific parameter range.

Physical Review B 89 (2014), 125432

Superconducting nano-mechanical diamond resonators

Tobias Bautze, Soumen Mandal, Oliver A Williams, Pierre Rodiere, Tristan Meunier and Christopher Bäuerle

abstract: In this work we present the fabrication and characterization of superconducting nano-mechanical resonators made from nanocrystalline boron doped diamond (BDD). The oscillators can be driven and read out in their superconducting state and show quality factors as high as 40,000 at a resonance frequency of around 10 MHz. Mechanical damping is studied for magnetic fields up to 3 T where the resonators still show superconducting properties. Due to their simple fabrication procedure, the devices can easily be coupled to other superconducting circuits and their performance is comparable with state-of-the-art technology.

Carbon 72 (2014), 100-105

Superconductivity in Nanostructured Boron-doped Diamond and its Application to Device Fabrication

Soumen Mandal, Tobias Bautze and Christopher Bäuerle

Nanodiamond 31 (2013), 385

The diamond superconducting quantum interference device

Soumen Mandal, Tobias Bautze, Oliver A Williams, Cecile Naud, Etienne Bustarret, Franck Omnes, Pierre Rodiere, Tristan Meunier, Christopher Bäuerle and Laurent Saminadayar

ACS nano 5 (2011), 7144-7148

Efficient radio frequency filters for space constrained cryogenic setups

Soumen Mandal, Tobias Bautze, Rémi Blinder, Tristan Meunier, Laurent Saminadayar and Christopher Bäuerle

Review of Scientific Instruments 82 (2011), 024704