Publications (13)
Normalized gradient flow optimization in the training of ReLU artificial neural networks
Simon Eberle, Arnulf Jentzen, Adrian Riekert +1
The training of artificial neural networks (ANNs) is nowadays a highly relevant algorithmic procedure with many applications in science and industry. Roughly speaking, ANNs can be…
Resolving the positions of defects in superconducting quantum bits
Alexander Bilmes, Anthony Megrant, Paul Klimov +4
Solid-state quantum coherent devices are quickly progressing. Superconducting circuits, for instance, have already been used to demonstrate prototype quantum processors comprising…
Rabi noise spectroscopy of individual two-level tunneling defects
Shlomi Matityahu, Jürgen Lisenfeld, Alexander Bilmes +4
Understanding the nature of two-level tunneling defects is important for minimizing their disruptive effects in various nano-devices. By exploiting the resonant coupling of these d…
Electric field spectroscopy of material defects in transmon qubits
Jürgen Lisenfeld, Alexander Bilmes, Anthony Megrant +6
Superconducting integrated circuits have demonstrated a tremendous potential to realize integrated quantum computing processors. However, the downside of the solid-state approach i…
Acoustic properties of metallic glasses at low temperatures -- tunneling systems and their dephasing
Arnold MeiÃner, Tim Voigtländer, Saskia M. MeiÃner +4
The low temperature acoustic properties of bulk metallic glasses measured over a broad range of frequencies rigorously test the predictions of the standard tunneling model. The str…
Dynamical Decoupling of Quantum Two-Level Systems by Coherent Multiple Landau-Zener Transitions
Shlomi Matityahu, Hartmut Schmidt, Alexander Bilmes +5
Increasing and stabilizing the coherence of superconducting quantum circuits and resonators is of utmost importance for various technologies ranging from quantum information proces…
Probing individual tunneling fluctuators with coherently controlled tunneling systems
Saskia M. MeiÃner, Arnold Seiler, Jürgen Lisenfeld +2
Josephson junctions made from aluminium and its oxide are the most commonly used functional elements for superconducting circuits and qubits. It is generally known that the disorde…
The Singular Set of Higher Dimensional Unstable Obstacle Type Problems
John Andersson, Henrik Shahgholian, Georg Weiss
In this paper we will investigate the singular points of the following unstable free boundary problem: {equation}\label{Eq} Îu= -Ï_{\{u>0\}} \quad\quad\textrm{in} B_1(0) {equatio…
Transmission-line resonators for the study of individual two-level tunneling systems
Jan David Brehm, Alexander Bilmes, Georg Weiss +2
Parasitic two-level tunneling systems (TLS) emerge in amorphous dielectrics and constitute a serious nuisance for various microfabricated devices, where they act as a source of noi…
Electronic Decoherence of Two-Level Systems in a Josephson Junction
Alexander Bilmes, Sebastian Zanker, Andreas Heimes +5
The sensitivity of superconducting qubits allows for spectroscopy and coherence measurements on individual two-level systems present in the disordered tunnel barrier of an $\mathrm…
Observation of directly interacting coherent two-level systems in a solid
Jürgen Lisenfeld, Grigorij J. Grabovskij, Clemens Müller +3
Parasitic two-level tunneling systems originating from structural material defects affect the functionality of various microfabricated devices by acting as a source of noise. In pa…
Classification of global solutions to the obstacle problem in the plane
Anthony Salib, Georg Weiss
Global solutions to the obstacle problem were first completely classified in two dimensions by Sakai using complex analysis techniques. Although the complex analysis approach produ…
Decoherence spectroscopy with individual two-level tunneling defects
Jürgen Lisenfeld, Alexander Bilmes, Shlomi Matityahu +7
Recent progress with microfabricated quantum devices has revealed that an ubiquitous source of noise originates in tunneling material defects that give rise to a sparse bath of par…