Project description DEENESFRITPL Investigating the quantum Higgs mode in superconductors The Higgs mode, otherwise known as the Higgs amplitude mode, is a condensed-matter analogue of the Higgs boson in particle physics. This quantum phenomenon seen in materials occurs when the magnetic field of its electrons fluctuate in a way similar to that of a Higgs boson. Whereas expected to exist in many different systems, the Higgs modes detection is always a challenge as they are often unstable and prone to decay. However, other systems can support these quantum effects without decaying. The aim of the EU-funded HiggS2 project is to further investigate a recently identified potential mechanism that makes the Higgs mode detectable by Raman spectroscopy. Major focus will be placed on studying Higgs mode stability in 2D superconductors. The project's results will provide useful insights into the quantum properties of superconductors. Show the project objective Hide the project objective Objective Collective modes are witnesses of their underlying quantum order, such as superconductivity. Experimental observations of the collective amplitude mode of the superconducting state, named the Higgs mode due to its analogy with the high energy particle, are still scarce and controversial, despite being a fundamental outcome of the theory of superconductivity. Besides, many crucial questions remain open, like the mechanism of its observability, its mere existence in two-dimensional or unconventional superconductors, to name a few. Similarly to the Higgs boson, its detection remains a challenge for physicists. I identified a potential mechanism of observability making the Higgs mode detectable by Raman spectroscopy, based on the interplay between an adjacent quantum order and superconductivity. I propose here to unravel and investigate the full capability of this mechanism, and to develop a new framework for the quest of the Higgs mode. A first objective is to unveil the key ingredients of this observability by diversifying the type of adjacent order. A second objective is to explore the Higgs mode observability and nature in unconventional situations; in exotic superconductors and in the proximity of quantum criticality. As third objective, I change the dimensionality of the systems and investigate the Higgs mode stability in two-dimensional superconductors. I propose to monitor the detectability and nature of the Higgs mode in this careful selection of situations using advanced Raman spectroscopic techniques under extreme conditions at very low temperature, under lattice-density tuning or high magnetic field. This project will establish definitive examples of the observation and mechanism of observability of the Higgs mode in superconductors, while developing its phenomenology to address major problems at the frontier of quantum materials research, with impact beyond mere superconductivity and even condensed matter. Fields of science natural sciencesphysical sciencestheoretical physicsparticle physicshiggs bosonsnatural sciencesphysical scienceselectromagnetism and electronicssuperconductivitynatural sciencesphysical sciencesopticsspectroscopy Programme(s) H2020-EU.1.1. - EXCELLENT SCIENCE - European Research Council (ERC) Main Programme Topic(s) ERC-2019-COG - ERC Consolidator Grant Call for proposal ERC-2019-COG See other projects for this call Funding Scheme ERC-COG - Consolidator Grant Coordinator CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS Net EU contribution € 1 817 028,00 Address Rue michel ange 3 75794 Paris France See on map Region Ile-de-France Ile-de-France Paris Activity type Research Organisations Links Contact the organisation Opens in new window Website Opens in new window Participation in EU R&I programmes Opens in new window HORIZON collaboration network Opens in new window Other funding € 0,00 Beneficiaries (2) Sort alphabetically Sort by Net EU contribution Expand all Collapse all CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS France Net EU contribution € 1 817 028,00 Address Rue michel ange 3 75794 Paris See on map Region Ile-de-France Ile-de-France Paris Activity type Research Organisations Links Contact the organisation Opens in new window Website Opens in new window Participation in EU R&I programmes Opens in new window HORIZON collaboration network Opens in new window Other funding € 0,00 Third-party Legal entity other than a subcontractor which is affiliated or legally linked to a participant. The entity carries out work under the conditions laid down in the Grant Agreement, supplies goods or provides services for the action, but did not sign the Grant Agreement. A third party abides by the rules applicable to its related participant under the Grant Agreement with regard to eligibility of costs and control of expenditure. UNIVERSITE GRENOBLE ALPES France Net EU contribution € 60 560,00 Address 621 avenue centrale 38058 Grenoble See on map Region Auvergne-Rhône-Alpes Rhône-Alpes Isère Activity type Higher or Secondary Education Establishments Links Contact the organisation Opens in new window Participation in EU R&I programmes Opens in new window HORIZON collaboration network Opens in new window Other funding € 0,00