Impact of structural chirality on the physical properties of a molecular superconductor

Superconductivity, the ultimate technology for energy savings due to its ability to transport and store energy without loss, also enables the development of quantum devices with unparalleled efficiency and sensitivity. Another strong trend involves the use of classical superconductors (such as aluminum) to form q-bits, the building blocks of current quantum computers. It has recently been proposed that the performance of quantum computers could be boosted by the use of superconducting building blocks that would be topologically protected and therefore more robust (with respect to decoherence processes): www.nature.com/articles/d41586-025-00527-z.

This thesis is based on the recent discovery by N. Avarvari's group in Angers (in collaboration with R. Kato and H. Cui of the Riken Institute in Japan) of a superconducting state induced by the application of moderate pressure (<1.5 GPa) to a molecular solid with a chiral crystal structure. Until now, the only known superconductors with a chiral crystal structure were inorganic, and only one enantiomer could be synthesized, making the detection of the impact of structural chirality on the properties of the superconducting state difficult. Molecular solids lift this significant constraint because a chiral center can be introduced within a molecule during solution synthesis with a well-defined chirality (left-handed or right-handed enantiomer). The synthesized molecule can then be crystallized to obtain the corresponding molecular superconductor, with a fully controlled structural chirality.

Through this project, we propose to study the impact of structural chirality on the physical properties of the superconducting and normal state of a molecular superconductor, whose crystalline structure is chiral. More specifically, we will establish the Temperature-Pressure phase diagram to highlight the different electronic phases competing with superconductivity, and we will study the superconducting diode effect and electrical magneto-chiral anisotropy (see figure).

This thesis proposes first to synthesize single crystals, then to determine the structural properties (pressure XRD, at ICMCB and the large ESRF/SOLEIL instrument), magnetic properties (pressure SQUID), and electronic transport properties (resistivity, Hall effect and quantum oscillations, non-reciprocal transport) under pressure, intense magnetic field, and at sub-Kelvin temperatures. The synthesis of single crystals is fully mastered by our partner Moltech-Angers (N. Avarvari) and its realization at ICMCB will be facilitated by the collaboration with F. Riobé (ICMCB).

The “Institut de Chimie de la Matière Condensée de Bordeaux” (UMR5026) is a Joint Research Unit of the CNRS, of the University of Bordeaux and Bordeaux INP.
The ICMCB has strong expertise in solid state chemistry, materials science and chemical processing. It uses this know-how for the development of new materials and new concepts for materials synthesis, shaping and recycling, covering the application fields energy, environment, health, electronics and photonics. Recently, the ICMCB has also become active in machine learning and artificial intelligence.

We are seeking a highly motivated candidate, interested in superconductivity, with a Master's degree in Physics. This thesis involves the preparation and manipulation of small samples under binocular microscopes. We are therefore seeking a meticulous and agile candidate who particularly enjoys painstaking work. Previous experience (internship) in the field of low-temperature physics and sample preparation would be an asset.