Alexis JOUAN - Personal Website

Postdoc at the University of Sydney

In 2018, I joined the Quantum Nanoscience Laboratory (QNL) as a postdoctoral researcher. The laboratory, lead by David Reilly, is situated in the Nanoscience Hub at the University of Sydney. The team is working in close collaboration with Microsoft Quantum.

My project was focused on dispersive gate sensing (DGS) in low dimensional systems. The advantage of this technique is the ability to probe the compressibility of an electronic system using gates. With Marie-Claire Jarratt (PhD student), we performed a DGS measurement of a quantum point contacts formed in GaAs 2DEGs [PRA 2020]. In parallel, I have been working with Andrew Dzurak's team at UNSW on dispersive gate sensing for readout of spin qubits in Silicon. Together with Anderson West and Bas Hensen, we have demonstrated the single shot readout of the electron spin in a double quantum dot in Silicon [Nat. Nano. 2019].

Topological Josephson Junctions

In 2019, I focused on building Josephson junctions in topological materials (InAs) using new fabrication techniques and characterize them at low temperature in the Nanoscience Hub facilities.

This work that I undertook in collaboration with Microsoft was pursuing a simple goal: how can we sculpt materials at the nanometer-scale without creating defects that lower the quality of the device? Reaching the ballistic limit is indeed crucial to be able to control topological excitations in condensed matter systems. Using anodization is a possible solution since it allows one to transform good metals into good insulators locally, without creating significant defects. In a recent APL publication [APL 2021], we demonstrate the fabrication of a Josephson junction in an InAs 2D electron gas using this method.

Postdoc at ENS Lyon

In 2020, in joined the Quantum Circuit group of Benjamin Huard and Audrey Bienfait. I worked on the effect of a dispersive readout on a Fluxonium qubit. This superconducting qubit is promissing for quantum computing because of its long lifetimes and fast qubit gates. Our experiments demonstrate in detail the effect of the readout on the transition rates.