High harmonic spectroscopy of quantum phases in a high-Tc superconductor

Ultrafast carrier dynamics are uniquely sensitive to the correlated interactions within quantum materials as well as their transition to different phases, like the emergence of superconductivity (SC) [1,2].We thank V. Kunets from MMR Technologies and X. Menino at Institut de Ciencies Fotoniques for technical support and Dr. K. Dewhurst and Dr. S. Sharma for help with the ELK code. J.B., U.E., T.P.H.S., T.S., and I.T. acknowledge financial support from the European Research Council (ERC) for ERC Advanced Grant “TRANSFORMER” (grant 788218) and ERC Proof of Concept Grant “miniX” (grant 840010). J.B. and group acknowledge support from FET -OPEN “PETACom” (grant 829153), FET-OPEN “OPTOlogic” (grant 899794), EIC-2021-PATHFINDEROPEN “TwistedNano” (grant 101046424), Laserlab-Europe (grant 654148), Marie Sklodowska-Curie ITN “smart-X” (grant 860553), Plan Nacional PID-PID2020-112664GB-I00-210901, AGAUR for 2017 SGR 1639, “Severo Ochoa” (grant SEV-2015-0522), Fundació Cellex Barcelona, the CERCA Programme/Generalitat de Catalunya, and the Alexander von Humboldt Foundation for the Friedrich Wilhelm Bessel Prize. U.B., T.G., P.T.G., and M.L. acknowledge funding from the ERC for ERC Advanced Grant NOQIA; Agencia Estatal de Investigación (R&D project CEX2019-000910-S, funded by MCIN/AEI/10.13039/501100011033, Plan National FIDEUA PID2019-106901GB-I00, FPI, QUANTERA MAQS PCI2019-111828-2, Proyectos de I+D+I “Retos Colaboración” RTC2019-007196-7); Fundació Cellex; Fundació Mir-Puig; Generalitat de Catalunya through the CERCA program; AGAUR grant 2017 SGR 134; QuantumCAT U16-011424, cofunded by ERDF Operational Program of Catalonia grant 2014-2020; EU Horizon 2020 FET-OPEN OPTOLogic (grant 899794); National Science Centre, Poland (Symfonia grant 2016/20/W/ST4/00314); Marie Skłodowska-Curie grant STREDCH 101029393; “La Caixa” Junior Leaders fellowships (ID100010434); and EU Horizon 2020 under Marie Skłodowska-Curie grant agreement 847648 (LCF/BQ/PI19/11690013, LCF/BQ/PI20/11760031, LCF/BQ/PR20/11770012, and LCF/BQ/PR21/11840013). P.T.G. acknowledges the Polish National Science Center grants 2018/31/N/ST2/01429 and 2020/36/T/ST2/00065 and is supported by the Foundation for Polish Science. Center for Theoretical Physics of the Polish Academy of Sciences is a member of the National Laboratory of Atomic, Molecular and Optical Physics. A.P. and J.A. acknowledge support from the Spanish Ministry of Economy and Competitiveness through the “Severo Ochoa” Programme for Centres of Excellence in R&D (grant SEV-2015-0496), SuMaTe project (RTI2018-095853-B-C21) cofinanced by the European Regional Development Fund, and the Catalan Government grant 2017-SGR-1519. This work was supported by EU COST action NANOCOHYBRI CA16218. M.C. acknowledges financial support from the Guangdong Province Science and Technology Major Project (Future functional materials under extreme conditions - 2021B0301030005). We also acknowledge the Scientific Services at Institut de Ciència de Materials de Barcelona and ICN2.With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).Peer reviewe