Attosecond x-ray transient absorption spectroscopy in graphene

Real-time observations of the coherent electron dynamics induced by ultrashort light pulses in condensed-matter systems have remained elusive due to limitations existing attosecond devices. Here we show that transient absorption resulting from an IR-pump/x-ray probe numerical experiment performed graphene unambiguously encodes information pump pulse. First, demonstrate possibility tracking real time injection through Dirac points. Second, derive and a simple semiclassical theory correlates energy structure action Berry phase with strong changes spectrum around Van Hove singularities. Our work opens way development novel imaging techniques condensed matter at timescale.Received 30 October 2020Accepted 27 January 2021DOI:https://doi.org/10.1103/PhysRevResearch.3.013144Published American Physical Society under terms Creative Commons Attribution 4.0 International license. Further distribution this must maintain attribution author(s) published article's title, journal citation, DOI.Published SocietyPhysics Subject Headings (PhySH)Research AreasTransport phenomenaUltrafast phenomenaPhysical SystemsGrapheneTechniquesDensity matrix methodsTransient spectroscopyCondensed Matter, Materials & Applied Physics