High-Performance Electron Spin Resonance Spectroscopy Enabled by High-Temperature Superconductors

Abstract:
Current electron spin resonance (ESR) spectrometers are limited by low sensitivity and large sample volume requirements, restricting investigations at the nanoscale. This PhD project addresses these limitations through the development of a highly sensitive ESR spectrometer leveraging high-temperature superconducting (HTS) resonators. This innovative approach promises to expand the capabilities of ESR for investigating quantum materials, spin dynamics, and other phenomena at the nanometer scale. The project combines cutting-edge microwave engineering, thin film microfabrication, and advanced quantum measurement methodologies. This represents a significant step in bringing ESR technique to the nanoscale

Context :

Electron Spin Resonance (ESR) is a powerful technique for probing the magnetic properties of materials at the atomic level, offering crucial insights into spin states, local environments, and interactions. While fundamental in chemistry, biology, physics, and particularly quantum science, current commercial ESR systems suffer from inadequate sensitivity and large sample volume requirements, hindering investigations of nanostructured materials and limiting applications. The advent of superconducting quantum technologies offers new avenues for overcoming these limitations. This PhD project aims to harness the potential of high-temperature superconductors (HTS) to develop a next-generation ESR spectrometer, promising enhanced sensitivity and operation across a wider temperature range than traditional systems.

This PhD project will develop a novel, high-sensitivity ESR spectrometer utilizing advanced HTS resonators. The core objective is to achieve at least a 1-2 order-of-magnitude improvement in spin sensitivity compared to commercial systems. Specific research areas include:

• Design and Fabrication: Utilizing electromagnetic simulation tools, microfabrication techniques (including optical lithography), and microwave characterization to design and optimize HTS resonators. We will primarily use YBCO thin films for the resonator material, with classical metallic resonators serving as benchmarks.
• Pulsed Microwave Bridge Development: Construction, testing, and optimization of a pulsed microwave bridge with the focus of enabling a wide range of advanced pulse sequences, such as Hahn echoes and nutation experiments. The experimental system will target the 5-40 GHz range, with particular focus on optimizing microwave coupling to small-scale samples.
• Benchmark and Validation: Rigorous comparison of the newly developed spectrometer against state-of-the-art commercial spectrometers using well-known spin-species such as DPPH. This step is crucial to quantify the actual improvement of the instrument.
• Exploring Innovative Samples: Investigation of novel small-scale spin samples, including defects in 2D materials and single spin centers in crystals, using the newly developed techniques.

This project is expected to:

• Achieve a significant, quantifiable enhancement in ESR spin sensitivity, thus opening new avenues for exploring nanoscale phenomena.
• Develop new pulsed ESR methodologies, thereby expanding capabilities to study spin dynamics and quantum phenomena in novel materials.
• Generate high-impact publications and presentations at international conferences, highlighting both technological advancements and new scientific understanding.
• Provide the PhD student with state-of-the-art technical expertise, preparing them for a leading career in cutting-edge quantum technologies research."

The successful candidate will join the Magnetism (MAG) Group at the IM2NP Laboratory which is a renowned research center in Marseille, with all facilities and expertise in materials science, nanotechnology, and condensed matter physics needed. Our environment allowed innovation and interdisciplinary collaboration, offering state-of-the-art tools for spectrometer development and advanced instrumentation.

As part of this project, the candidate will have access to IM2NP’s state-of-the-art platforms for electromagnetic simulations, cryogenic setups, and high-frequency instrumentation. Collaboration within the INFRANALYTICS national platform enhances access to high-performance analytical tools and fosters interactions with experts in spectroscopy and instrumentation across France. This integrated network offers a unique opportunity to work at the frontier of quantum technologies while benefiting from a robust infrastructure for innovation

More information on https://www.im2np.fr/fr/equipe-magnetisme-mag

Beyond the laboratory, Marseille and Provence offer an environment for both professional and personal fulfillment. Marseille, France’s second-largest city, is a vibrant Mediterranean hub renowned for its rich cultural heritage, dynamic lifestyle, and thriving scientific community

The candidate must hold a Master degree in physics, nanosciences, or an equivalent, by the end of summer 2025. He/she should have a solid background in experimental condensed matter and quantum physics and be strongly motivated in instrumental development.

Skills in Python coding would also be appreciated.