title: THz saturable absorption in turbostratic multilayer graphene on silicon carbide.
abstract: We investigated the room-temperature Terahertz (THz) response as saturable absorber of turbostratic multilayer graphene grown on the carbon-face of silicon carbide. By employing an open-aperture z-scan method and a 2.9 THz quantum cascade laser as source, a 10% enhancement of transparency is observed. The saturation intensity is several W/cm2, mostly attributed to the Pauli blocking effect in the intrinsic graphene layers. A visible increase of the modulation depth as a function of the number of graphene sheets was recorded as consequence of the low nonsaturable losses. The latter in turn revealed that crystalline disorder is the main limitation to larger modulations, demonstrating that the THz nonlinear absorption properties of turbostratic graphene can be engineered via a proper control of the crystalline disorder and the layers number.
authors.forename: Federica
authors.initials: F
authors.lastname: Bianco
authors.forename: Vaidotas
authors.initials: V
authors.lastname: Miseikis
authors.forename: Domenica
authors.initials: D
authors.lastname: Convertino
authors.forename: Ji-Hua
authors.initials: JH
authors.lastname: Xu
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Castellano
authors.forename: Harvey E
authors.initials: HE
authors.lastname: Beere
authors.forename: David A
authors.initials: DA
authors.lastname: Ritchie
authors.forename: Miriam S
authors.initials: MS
authors.lastname: Vitiello
authors.forename: Alessandro
authors.initials: A
authors.lastname: Tredicucci
authors.forename: Camilla
authors.initials: C
authors.lastname: Coletti