News

g-factorcontrib

Published in PRL: Isotropic and Anisotropic g-Factor Corrections in GaAs Quantum Dots

The spin splitting defines the energy of the spin qubit and is one of the fundamental properties of a spin in a B-field. Here, we measure and separate the isotropic and anisotropic corrections to the g-factor in two GaAs devices, finding…
ML tuning

On arXiv: Machine Learning Tuning of Silicon and SiGe-based Quantum Devices

Device-to-device variability and disorder in spin qubits makes it currently necessary to individually tune each device in a large-dimensional gate space to find the optimal conditions for qubit operation. We take a key step with a…
BZTeleBasel

BZ Basel Interview and TeleBasel Videoreport on Exclusion of CH from Horizon Europe Program

The recent exclusion of Switzerland from the EU reserach program Horizon Europe has lead to an interview with Dominik appearing in BZ Basel and also on Telebasel. The Lab is also featured nicely on the video, which also shows Omid…
QMULT

Quantum Matter at Ultralow Temperatures, Institute of Physics Online Event

The online meeting Quantum Matter at Ultralow Temperatures is taking plase July 20-21, organized by Edward Laird, Samuli Autti (Lancaster) and Attila Geresdi (Chalmers) and supported by the Institute of Physics and Condensed Matter division…
LukasSchenk

Matura Thesis Presentation Lukas Schenk

From Mon May 31 to Fri, Jun 25, Lukas Schenk from the Gymnasium Thun was working on his Matura Thesis in our laboratory, investigating the quality of various dielectrics via capacitance spectroscopy in special test capacitors which Lukas…
learning

npj Quantum Information: Finding bias triangles with deep reinforcement learning

Deep reinforcement learning is an emerging machine learning approach which can teach a computer to learn from actions and rewards similar to the way humans learn from experience. Here, we use this approach for fully automatic identification…
Mobility Curves

On arXiv: High mobility SiMOSFETs fabricated in a full 300mm CMOS process

The quality of SiMOSFET gate stacks plays a key role for hosting spin qubits. Here, we report a record electron mobility of 17'500 cm2/Vs with sub-10nm oxide, indicating a relatively low disorder FET. We find very good agreement with the…
section

Published in PRB: Low-symmetry nanowires for enhanced Dresselhaus spin-orbit interaction

While the Dresselhaus SOI is suppressed for select zinc-blende nanowire growth directions and confinements, some configurations allow for a strong Dresselhaus SOI. A similarly strong Rashba term can be gate-induced, providing a means to…
EPGHS-8

Emergent Phenomena in Quantum Hall Systems 8 Online Workshop

The 8-th International Workshop on Emergent Phenomena in Quantum Hall Systems, organized by Mansour Shayegan at Princeton University, started off today with Invited Guest and Nobel Loreate Klaus von Klitzing giving the opening speech. The…
Rahel

Rahel Kaiser has joined the group to work on MSc thesis

Rahel Kaiser (Nanoscience BSc, Basel) joined the group today to work on her masters thesis, focusing on Ge/Si nanowire qubits in our spin qubit team, in collaboration with Taras Patlatiuk as a co-advisor. Welcome to the group, Rahel, and…
Rafael

Rafael Eggli defended his MSc Thesis

Rafael Eggli presented the results of his MSc thesis "Charge Sensing with Silicon Quantum Dots" to the group today on zoom and in neuer HS1, with Andreas Kuhlmann as co-advisor. Rafael not only set up a complete new VTI system with 6 coaxes…
Miguels talk

March Meeting 2021 taking place online...

Conferences such as the March Meeting of the American Physical Society are a great opportunity to present results, meet other scientists, get exposed to questions, and engage in dialogue... particularly when the next speaker did not appear…
finFET

On arXiv: A spin qubit in a fin field-effect transistor

Scaling up is quantum computing's greatest challenge. Silicon fin field-effect transistors (finFETs) are the pinnacle of decades of large scale integration and scaling to billions of transistors each of few-nm size. Here, we demonstrate…
APS MM 2021

APS March Meeting 2021 Online: Zumbühl Group Talks

A30.03 Mobility limiting factors in Si-MOSFETs in full CMOS process Tim Camenzind (Mon 2:00 pm - 5:00 pm) session link J29.10 Isotropic and Anisotropic g-factor Corrections in GaAs Quantum Dots Simon Svab (Tue 9:00 pm - 12 am), session link…
finFET

Published as Editor's pick in APL: Silicon quantum dots with a self-aligned gates

We present silicon finFET quantum dots with perfectly self-aligned 2nd gate layer and gate lengths down to 15 nm. The fabrication is industry compatible and scalable and gives very high quality devices. We observe Pauli spin blockade and…