{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"submitter":["Bykov AY"],"funding":["European Commission","Research Councils UK"],"pagination":["3744-3749"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC10979426"],"repository":["biostudies-literature"],"omics_type":["Unknown"],"volume":["24(12)"],"pubmed_abstract":["Ultrafast nonlinearity, which results in modulation of the linear optical response, is a basis for the development of time-varying media, in particular those operating in the epsilon-near-zero (ENZ) regime. Here, we demonstrate that the intraband excitation of hot electrons in the ENZ film results in a second-harmonic resonance shift of ∼10 THz (40 nm) and second-harmonic generation (SHG) intensity changes of >100% with only minor (<1%) changes in linear transmission. The modulation is 10-fold enhanced by a plasmonic metasurface coupled to a film, allowing for ultrafast modulation of circularly polarized SHG. The effect is described by the plasma frequency renormalization in the ENZ material and the modification of the electron damping, with a possible influence of the hot-electron dynamics on the quadratic susceptibility. The results elucidate the nature of the second-order nonlinearity in ENZ materials and pave the way to the rational engineering of active nonlinear metamaterials and metasurfaces for time-varying applications."],"journal":["Nano letters"],"pubmed_title":["Time-Dependent Ultrafast Quadratic Nonlinearity in an Epsilon-Near-Zero Platform."],"pmcid":["PMC10979426"],"funding_grant_id":["EP/Y015673/1","789340"],"pubmed_authors":["Li G","Bykov AY","Zayats AV","Deng J"],"additional_accession":[]},"is_claimable":false,"name":"Time-Dependent Ultrafast Quadratic Nonlinearity in an Epsilon-Near-Zero Platform.","description":"Ultrafast nonlinearity, which results in modulation of the linear optical response, is a basis for the development of time-varying media, in particular those operating in the epsilon-near-zero (ENZ) regime. Here, we demonstrate that the intraband excitation of hot electrons in the ENZ film results in a second-harmonic resonance shift of ∼10 THz (40 nm) and second-harmonic generation (SHG) intensity changes of >100% with only minor (<1%) changes in linear transmission. The modulation is 10-fold enhanced by a plasmonic metasurface coupled to a film, allowing for ultrafast modulation of circularly polarized SHG. The effect is described by the plasma frequency renormalization in the ENZ material and the modification of the electron damping, with a possible influence of the hot-electron dynamics on the quadratic susceptibility. The results elucidate the nature of the second-order nonlinearity in ENZ materials and pave the way to the rational engineering of active nonlinear metamaterials and metasurfaces for time-varying applications.","dates":{"release":"2024-01-01T00:00:00Z","publication":"2024 Mar","modification":"2025-04-22T21:34:35.855Z","creation":"2025-04-06T03:35:08.95Z"},"accession":"S-EPMC10979426","cross_references":{"pubmed":["38483127"],"doi":["10.1021/acs.nanolett.4c00282"]}}