Lossless resilient microwave components based on disordered superconductors H/F

Lossless Resilient Microwave Components Based on Disordered Superconductors H/F

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Post-doctorat

Lossless resilient microwave components based on disordered superconductors.

During the last decades, superconducting quantum circuits have shown impressive results fueled by the so-called circuit Quantum ElectroDynamics (cQED) architecture where the quantum signal is carried by photons at microwave frequencies. cQED experiments often rely on the technology of aluminum Josephson Junctions (JJ's) which can be understood as non-linear inductors. This non-linearity allowed the development of numerous non-linear lossless microwave components (tunable resonators, low noise amplifiers, etc.) which became essential tools for state-of-the-art cQED experiments. Yet, as a consequence of being built upon aluminum JJ's, all of these components are restricted to low magnetic field (≲ 250mT), temperature (≲ 250mK), and frequency (≲ 10 GHz), strongly limiting the range of their application. The use of disordered superconductors with a large superconducting gap such as NbN would alleviate these constraints by one order of magnitude.

The goal of the project is to demonstrate that the non‐linearity of large gap disordered superconductors, here NbN, can advantageously replace Al JJ’s in order to offer lossless microwave components to research communities working at large magnetic field (∼ 6 T), temperature (∼ 4 K), and frequency (∼ 100 GHz).

PostDoc candidates are required to have a Ph.D. degree in physics or a related discipline (electrical engineering, nanosciences, etc.). The successful candidate will bring a strong background in some of the following areas: superconducting quantum circuit, superconducting qubits, device nanofabrication, cryogenic experiments, experiment control, and data acquisition. Strong Python programming knowledge is a clear asset. French language proficiency is not necessary. The candidate will work within a team of researchers and will advise graduate and undergraduate students in their research projects.

How to Apply

To apply, please contact Étienne Dumur by email (etienne.dumur@cea.fr) including:

1. a curriculum vitae (including prior research experience and skills acquired as well as names of potential referees)
2. your academic records (Master’s and PhD diploma)
3. a list of publications
4. a short statement of your research interest and how it relates to the project

Site

Grenoble

Référence

2025-35179

The Fundamental Research Department conducts outstanding research in the fields of physics, chemistry, biology, climate, and environmental sciences. Our research group (www.lateqs.fr), hosted at CEA Grenoble, is part of the French national “Plan Quantique” and closely collaborates with in-house theory colleagues. The lab is located on a big scientific campus gathering not only CEA with its strong microelectronics research (300 mm clean room) but also other major scientific institutions such as CNRS (Institut Néel), ERSF (synchrotron), ILL (neutron source), and many high-tech companies as well as the University Grenoble Alpes.

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