Research Activities
Semiconductor spin qubits: device physics and control
Our goal is to demonstrate scalable device and material platforms for spin qubits where the DiVincenzo criteria are robustly fulfilled. Our activities are based on a feedback loop between advanced simulations, device operation and optimization, and explore different material platforms, such as GaAs and SiGe. more...
Advanced materials for spin-based qubits
The quality and the reproducibility of spin-qubits hosted in gate-defined quantum dots are intimately related to the quality of the host material and of the fabrication technology. In collaboration with external partners, we investigate how material aspects, such as isotopic composition and crystallographic perfection, affects the performance of spin-qubits in Si/SiGe. Furthermore, we exploring the potential of non-conventional materials such as ZnSe for hosting spin-based qubits and for realizing spin-photon interfaces. more...
Long-distance on-chip qubit coupling
The realization of a coherent link between separated qubits on a chip remains one of the main challenges for the realization of a quantum computer based on semiconductor spin qubits. We are working towards the demonstration of a quantum bus (QuBus) that coherently transfers a single electron with an arbitrary spin state between quantum dots separated by 1 to 10 microns. more...
Coherent optical interfaces
Building a quantum network requires being able to interconvert flying qubits encoded into photons into stationary ones (e.g. spin qubits). Currently, qubits with good prospects for scaling to large numbers provide no optical interface, while optically addressable systems appear difficult to scale. We aim at establishing the fundamentals for quantum networks consisting of potentially scalable semiconductor spin qubits in gated GaAs quantum dots. more...
Scalable technologies for multi-qubit devices
A universal quantum computer will likely require millions (if not billions) of qubits. Its feasibility is therefore directly related to the scalability of its building blocks. In collaboration with external partners, we pursue an interdisciplinary approach across physics and engineering to tackle some of the major challenges related to the scalability of spin qubits, which go from identifying scalable device architectures, to high-yield fabrication, to automated tuning, to scalable solutions for the control electronics of the individual qubits. more...
Scanning SQUID microscopy
The activity on scanning SQUID spectroscopy is based on a SQUID microscope operating at temperatures down to 20 mK and optimized for high frequency measurements. The high sensitivity of this instrument makes it a perfect tool for the investigation of quantum phenomena such as persistent currents, molecular magnets, surface spins and topological Majorana-related states. more...