Zobrazeno 1 - 10
of 74
pro vyhledávání: '"Winzer, Torben"'
Autor:
Malic, Ermin, Winzer, Torben, Wendler, Florian, Brem, Samuel, Jago, Roland, Knorr, Andreas, Mittendorff, Martin, König-Otto, Jacob C., Plötzing, Tobias, Neumaier, Daniel, Schneider, Harald, Helm, Manfred, Winnerl, Stephan
Graphene is an ideal material to study fundamental Coulomb- and phonon-induced carrier scattering processes. Its remarkable gapless and linear band structure opens up new carrier relaxation channels. In particular, Auger scattering bridging the valen
Externí odkaz:
http://arxiv.org/abs/1810.06303
Publikováno v:
Phys. Status Solidi B 253, 2303 (2016)
The remarkable gapless and linear band structure of graphene opens up new carrier relaxation channels bridging the valence and the conduction band. These Auger scattering processes change the number of charge carriers and can give rise to a significa
Externí odkaz:
http://arxiv.org/abs/1609.06356
Autor:
Winzer, Torben, Mittendorff, Martin, Winnerl, Stephan, Helm, Manfred, Malic, Ermin, Knorr, Andreas
We present a joint theory-experiment study on the transmission/absorption saturation after ultrafast pulse excitation in graphene. We reveal an unconventional double-bended saturation behavior: Both bendings separately follow the standard saturation
Externí odkaz:
http://arxiv.org/abs/1607.00870
Publikováno v:
Sci. Rep. 5, 16841 (2015)
We present a microscopic study on the impact of doping on the carrier dynamics in graphene, in particular focusing on its influence on the technologically relevant carrier multiplication in realistic, doped graphene samples. Treating the time- and mo
Externí odkaz:
http://arxiv.org/abs/1508.06783
Autor:
Winzer, Torben, Ciesielski, Richard, Handloser, Matthias, Comin, Alberto, Hartschuh, Achim, Malic, Ermin
Publikováno v:
Nano Lett. 15, 1141 (2015)
We present a joint theory-experiment study on ultrafast photoluminescence from photoexcited graphene. Based on a microscopic theory, we reveal two distinct mechanisms behind the occurring photoluminescence: Besides the well-known incoherent contribut
Externí odkaz:
http://arxiv.org/abs/1411.0531
Publikováno v:
Phys. Rev. B 92, 085407 (2015)
In contrast to conventional structures, efficient non-radiative carrier recombination counteracts the appearance of optical gain in graphene. Based on a microscopic and fully quantum-mechanical study of the coupled carrier, phonon, and photon dynamic
Externí odkaz:
http://arxiv.org/abs/1409.8182
Publikováno v:
Phys. Rev. B 90, 075438 (2014)
Topological insulators represent a paradigm shift in surface physics. The most extensively studied Bi$_2$Se$_3$-type topological insulators exhibit layered structures, wherein neighboring layers are weakly bonded by van der Waals interactions. Using
Externí odkaz:
http://arxiv.org/abs/1408.5188
Publikováno v:
Phys. Rev. Lett. 113, 035502 (2014)
We present a microscopic explanation of the controversially discussed transient negative differential transmission observed in degenerate optical pump-probe measurements in graphene. Our approach is based on the density matrix formalism allowing a ti
Externí odkaz:
http://arxiv.org/abs/1404.1609
Autor:
Mittendorff, Martin, Winzer, Torben, Malic, Ermin, Knorr, Andreas, Berger, Claire, de Heer, Walter A., Schneider, Harald, Helm, Manfred, Winnerl, Stephan
Publikováno v:
Nano Lett., 2014, 14 (3)
We investigate the polarization dependence of the carrier excitation and relaxation in epitaxial multilayer graphene. Degenerate pump-probe experiments with a temporal resolution of 30 fs are performed for different rotation angles of the pump-pulse
Externí odkaz:
http://arxiv.org/abs/1312.5860
Publikováno v:
Phys. Rev. B 87, 165413 (2013)
A transient femtosecond population inversion in graphene was recently reported by Li et al., Phys. Rev. Lett. 108, 167401 (2012). Based on a microscopic theory we clarify the underlying microscopic mechanism: Transient gain and population inversion i
Externí odkaz:
http://arxiv.org/abs/1209.4833