相关论文: Ultrafast THz Faraday Rotation in Graphene
We present measurements of the transient photoconductivity in pentacene single crystals using optical-pump THz-probe spectroscopy. We have measured the temperature and fluence dependence of the mobility of the photoexcited charge carriers…
We study the generation of THz radiation from the acceleration of ultrafast photoexcited charge carriers in graphene in the presence of a DC electric field. Our model is based on calculating the transient current density from the…
The ultrafast relaxation and recombination dynamics of photogenerated electrons and holes in epitaxial graphene are studied using optical-pump Terahertz-probe spectroscopy. The conductivity in graphene at Terahertz frequencies depends on…
Optical pump-terahertz probe spectroscopy has been used to investigate ultrafast photo-induced charge carrier transport in 3.4 $\mu$m wide graphene ribbons upon scaling the optical pump intensity. For low pump fluences, the deposited pump…
We employ ultrabroadband terahertz (THz) spectroscopy to expose the high-frequency transport properties of Dirac fermions in monolayer graphene. By controlling the carrier concentration via tunable electrical gating, both equilibrium and…
We investigated ultrafast carrier dynamics in graphene with near-infrared transient absorption measurement after intense half-cycle terahertz pulse excitation. The terahertz electric field efficiently drives the carriers, inducing large…
We theoretically study the population inversion and negative dynamic conductivity in intrinsic graphene in the terahertz (THz) frequency range upon pulse photoexcitation with near-/mid-infrared wavelength. The threshold pulse energy…
We investigated negative photoconductivity in graphene using ultrafast terahertz techniques. Infrared transmission was used to determine the Fermi energy, carrier density and mobility of p-type CVD graphene samples. Time-resolved terahertz…
Dynamics of plasmons in nanoribbons of (hydrogen intercalated) quasi-free-standing single layer graphene is studied by terahertz spectroscopy both in the steady state and upon photoexcitation by an ultrashort near infrared laser pulse. The…
We demonstrate terahertz (THz) imaging and spectroscopy of a 15x15-mm^2 single-layer graphene film on Si using broadband THz pulses. The THz images clearly map out the THz carrier dynamics of the graphene-on-Si sample, allowing us to…
We theoretically investigate the ultrafast terahertz(THz) properties of monolayer graphene. The analytical formulations of the photon carrier, electric polarization and optical current are obtained by solving the Bloch-equations in present…
We report on the observation of the circular transversal terahertz photoconductivity in monolayer graphene supplied by a back gate. The photoconductivity response is caused by the free carrier absorption and reverses its sign upon switching…
THz Time-Resolved Photoconductivity is used to probe carrier dynamics in the dilute III-V nitride GaP0.49As0.47N0.036. In these measurements a femtosecond optical pump-pulse excites electron-hole pairs, and a delayed THz pulse measures the…
We study broadband terahertz (THz) conductivity and ultrafast photoconductivity spectra in lithographically fabricated multilayer epitaxial graphene nanoribbons grown on C- face of 6H-SiC substrate. THz near-field spectroscopy reveals local…
We performed terahertz magneto-optical spectroscopy of FeSe thin film to elucidate the charge carrier dynamics. The measured diagonal (longitudinal) and off-diagonal (Hall) conductivity spectra are well reproduced by two-carrier Drude…
The carrier dynamics of photoexcited electrons in the vicinity of the surface of (NH4)2S-passivated GaAs were studied via terahertz (THz) emission spectroscopy and optical-pump THz-probe spectroscopy. THz emission spectroscopy measurements,…
Using a spatially structured, optical pump pulse with a THz probe pulse, we are able to determine spatial variations of the ultrafast THz photoconductivity with sub-wavelength resolution (75 $\mu m \approx \lambda/5$ at 0.8 THz) in a planar…
Using ultrafast optical pump-probe spectroscopy, we have measured carrier relaxation times in epitaxial graphene layers grown on SiC wafers. We find two distinct time scales associated with the relaxation of nonequilibrium photogenerated…
Using synchronized near-infrared (NIR) and terahertz (THz) lasers, we have performed picosecond time-resolved THz spectroscopy of transient carriers in semiconductors. Specifically, we measured the temporal evolution of THz transmission and…
We consider a graphene sheet encapsulated in a two-dimensional metallic grating and a substrate ($\mathrm{Al_{2}O_{3}}$) and subjected to an external magnetic field (in Faraday configuration). The grating consists of a thin perfectly…