Doctorat (M/F) - circuits quantiques hybrides

CNRS; France; Sur place; EUR 18 000 - 24 000; Plein temps

Résumé du poste

CNRS – Laboratoire de Physique, ENS de Lyon, invites applications for a First Stage Researcher (R1) position in the Quantum Circuits group.

The project investigates molecular spins integrated on a superconducting chip to realize a microwave quantum memory, with access to nano-fabrication and cryogenic facilities. The candidate will perform measurements at millikelvin temperatures and analyze coherence and coupling to resonators.

Qualifications

• Expertise in high-frequency microwave measurements.
• Experience in scientific computing and Python.
• Proficiency with Git and software engineering practices.
• Ability to work independently and contribute to a thesis project.

Responsabilités

• Measure coherence of molecular spins at millikelvin temperatures.
• Characterize coupling to a low-impedance superconducting resonator.
• Assess molecular spin systems for microwave quantum memory suitability.
• Analyze experimental data and support theory where applicable.

Connaissances

High-frequency microwave measurements

Scientific computing

Software engineering (Python, Git)

Independent work

Formation

PhD candidate

Outils

Python

Git

Description du poste

Organisation/Company CNRS Department Laboratoire de Physique Research Field Mathematics History » History of science Researcher Profile First Stage Researcher (R1) Application Deadline 13 Nov 2026 - 23:59 (UTC) Country France Type of Contract Temporary Job Status Full-time Hours Per Week 35 Offer Starting Date 1 Jan 2027 Is the job funded through the EU Research Framework Programme? Not funded by a EU programme Is the Job related to staff position within a Research Infrastructure? No

Offer Description

Integration into the 'Quantum Circuits' research group within the Physics Laboratory at ENS de Lyon. Access provided to numerical tools, nanofabrication facilities, and cryogenic equipment.

A quantum memory allows for the simultaneous storage of a large number of quantum states and can reduce the qubit overhead of a quantum processor. Ensembles of electron spins coupled to a resonator are a promising candidate for storing propagating microwave states: spin species with long coherence times ensure durable storage, while an inhomogeneously broadened spectral line allows for the addressing of numerous spectral and temporal modes within a single device. Storage efficiency is determined by the coupling between the ensemble and the superconducting resonator used to address it. The ensembles proposed to date rely on crystalline matrices, in which spin density, the nuclear environment, and geometry are fixed during the growth process.
This project replaces the crystal with a deposited molecular film. The spin is implemented via a molecule: its nuclear environment is defined during synthesis, its concentration is determined by mass, and it is integrated onto a pre-fabricated superconducting chip via drop-casting or spin-coating. This thesis will explore several candidates: perchlorotriphenylmethyl and tetrathiatriarylmethyl (trityl) radicals—which exhibit a narrow spectral line and, when isotopically labeled, an addressable nuclear spin—as well as lanthanide complexes, such as Lu(II) or Yb(III) species, whose hyperfine structure offers "clock transitions." Both families combine the potential for long coherence times with structural properties compatible with strong coupling to a planar resonator.
The work will involve measuring the coherence of the selected candidates at millikelvin temperatures—a regime in which none of them have yet been characterized—as well as their coupling to a low-impedance resonator designed to maximize interaction with the spins. The objective of this thesis is a quantitative assessment of the capacity of these molecular spins to reach the regime required for a microwave quantum memory.

Expected knowledge

• Physical sciences (superconductivity, low temperatures, experimental setups, magnetic resonance)
• High-frequency microwave engineering
• Nanofabrication

Operational skills

• Expertise in high-frequency microwave measurements
• Scientific computing
• Software engineering (proficiency in Python, Git)
• Ability to work independently