Epitaxial growth of integrated nanostructures for quantum device fabrication (M/F)

Job Description

Thesis Subject

In the frame of the ANR PRC PEPITO, founded by the ANR in collaboration with LETI, NEEL and LAAS, the thesis project aims at the integration of low electron effective mass and strong spin orbit coupling semiconductors on silicon substrate via nanoscale selective area molecular beam epitaxy. These nanostructures will be combined with an epitaxial superconducting metal to achieve high quality nano-hybrids. This would be a real breakthrough for the development of quantum technologies based on gate-tunable superconducting transmons or topologial superconductivity.

Your Work Environment

To overcome the limitations of quantum computers based on conventional superconductors, it is necessary to develop technology that enables the manufacture of quantum bits that are robust against decoherence. Among the technological solutions being considered, bound quasi-particles known as Majorana particles, which can emerge at the ends of a one-dimensional topological superconductor, appear to be a complex but attractive solution. The creation of such a material is theoretically possible by combining a semiconductor nanowire with strong spin-orbit coupling and a conventional superconductor. Initial results in this field have shown the key role of the crystalline quality of the semiconductor/superconductor interface in the observation of a topological superconducting phase. These results were obtained using vertical InSb or InAs nanowires produced by VLS growth and then transferred to a host substrate for subsequent integration into an electronic device. Subsequent developments, notably those achieved by IEMN, LETI and NEEL as part of the Inspiring project, have demonstrated the possibility of using selective epitaxy of planar InAs, InSb or HgTe nanowires to achieve a more robust and reliable technology.
In the Pepito project, we propose, in partnership with LAAS, to add a locally epitaxial superconducting shell to planar nanowires with strong spin-orbit coupling (InAs, InSb, HgTe or BiSb) developed by selective growth. This technology, in addition to furthering the quest for Majorana quasiparticles, also offers prospects for the manufacture of gate-tunable Josephson junctions, which are of great interest for the implementation of qubits with adjustable critical current and reduced crosstalk. The ultimate goal of the project is to integrate these hybrid nanostructures on a silicon substrate to enable monolithic integration with cryogenic CMOS control systems with low heat dissipation. The electronic properties of the integrated hybrid nanostructures will be studied in NEEL using cryogenic magneto-transport measurements on elementary Josephson junction devices. The aim is to highlight the transparency of the hybrid interfaces and the topological phase of these junctions.
In this frame, the hired PhD student will develop the process enabling the selective growth of the different materials investigated by the consortium, focusing on InAs and InSb at IEMN. He will also ensure the characterization of the grown nanostructures using AFM and SEM microscopy and the fabrication of the nano-devices using e-beam lithography, metal evaporation and reactive ion etching techniques.

Constraints and risks

A large part of the thesis activity will involved work in clean room environment.
Suitable candidates should have a Master's degree (or equivalent) in a relevant field and experience in nanofabrication or materials science. Applicants should also have a good level of written and spoken English.

Compensation and benefits

Compensation

2300 € gross monthly

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

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