Shining light on Superconducting collective modes in 2D transition metal dichalcogenides – SUPER2DTMD

Light control of a material’s properties is an emerging field with potentially far-reaching applications. Within this field enhancing or modifying superconductivity (SC) holds a special place ever since the discovery of a superconducting-like state in several materials well above their equilibrium SC temperature. The dynamics of superconductors when driven out-of-equilibrium is governed by their collective mode spectrum, and in particular the SC amplitude mode which is an analog of the Higgs mode of high-energy physics. These SC collective modes give fingerprints of the nature of the ground state and its coupling to other intertwined states, but also provide a path to dynamically drive or even control SC order.

Light control of SC can be achieved following two distinct routes. The first one is to drive the relevant collective modes to dynamically modify materials properties such as the SC pairing potential and explore new regions of the free energy landscape inaccessible via static means. A second promising route is to dress the SC collective modes with “vacuum” photons exploiting strong-light matter coupling in cavities. The field of light control SC is still in its infancy, and none of these routes has been experimentally demonstrated up to now.

SUPER2DTMD propose to follow those two routes and use 2D transition metal dichalcogenides (TMD) as an ideal platform to demonstrate control of SC via coupling collective modes to light. TMDs offer a fertile playground to explore novel exotic states of matter with, e.g., topological order due to their quasi-2D character and strong spin-orbit coupling. Using complementary THz and Raman spectroscopic tools, SUPER2DTMD will first aim at better understanding the collective modes spectrum of TMDs and reveal possible exotic SC orders in 2D. It will then investigate SC TMD in the unchartered regimes of periodically driven non-equilibrium and strong light-matter coupling.