Coulomb oscillations in three-layer graphene nanostructures (2008)
Guettinger, J., Stampfer, C., Molitor, F., Graf, D., Ihn, T., Ensslin, K.
We present transport measurements on a tunable three-layer graphene single electron transistor (SET). The device consists of an etched three-layer graphene flake with two narrow constrictions...
Raman imaging of doping domains in graphene on SiO2 (2007)
Stampfer, C., Wirtz, L., Jungen, A., Graf, D., Molitor, F., Hierold, C., ...
We present spatially resolved Raman images of the G and 2D lines of single-layer graphene flakes. The spatial fluctuations of G and 2D lines are correlated and are thus shown to be affiliated with...
Tunable Coulomb blockade in nanostructured graphene (2007)
Stampfer, C., Guettinger, J., Molitor, F., Graf, D., Ihn, T., Ensslin, K.
We report on Coulomb blockade and Coulomb diamond measurements on an etched, tunable single-layer graphene quantum dot. The device consisting of a graphene island connected via two narrow graphene...
Raman imaging and electronic properties of graphene (2007)
Molitor, F., Graf, D., Stampfer, C., Ihn, T., Ensslin, K.
Graphite is a well-studied material with known electronic and optical properties. Graphene, on the other hand, which is just one layer of carbon atoms arranged in a hexagonal lattice, has been...
Local gating of a graphene Hall bar by graphene side gates (2007)
Molitor, F., Güttinger, J., Stampfer, C., Graf, D., Ihn, T., Ensslin, K.
We have investigated the magnetotransport properties of a single-layer graphene Hall bar with additional graphene side gates. The side gating in the absence of a magnetic field can be modeled by...
Phase coherent transport in a side-gated mesoscopic graphite wire (2007)
Graf, D., Molitor, F., Ihn, T., Ensslin, K.
We investigate the magnetotransport properties of a thin graphite wire resting on a silicon oxide substrate. The electric field effect is demonstrated with back and side gate electrodes. We study the...
IKOPA - Kulturwandel in klein- und mittelständischen Unternehmen (2007)
Generally, small companies regard management concepts very critically. Changes have to promise tangible profit and must be easily integrable into everyday business. Fraunhofer IPK is meeting these...
Spatially Resolved Raman Spectroscopy of Single- and Few-Layer Graphene (2006)
Graf, D., Molitor, F., Ensslin, K., Stampfer, C., Jungen, A., Hierold, C., ...
We present Raman spectroscopy measurements on single- and few-layer graphene flakes. Using a scanning confocal approach we collect spectral data with spatial resolution, which allows us to directly...
Local oxidation of Ga[Al]As heterostructures with modulated tip-sample voltages (2006)
Graf, D., Frommenwiler, M., Studerus, P., Ihn, T., Ensslin, K., Driscoll, D. C., ...
Nanolithography based on local oxidation with a scanning force microscope has been performed on an undoped GaAs wafer and a Ga[Al]As heterostructure with an undoped GaAs cap layer and a shallow...
Magnetic Field Dependence of CDW Phases in Per2M(mnt)2 (M=Pt, Au) (2005)
Brooks, J. S., Graf, D., Choi, E. S., Almeida, M., Dias, J. C., Henriques, R. T., ...
Recently the authors discovered that the suppression of the charge density wave (CDW) ground states by high magnetic fields in the organic conductor series Per2M(mnt)2 is followed by additional high...
Magnetic Field Dependent Behavior of the CDW ground state in Per2M(mnt)2 (M = Au, Pt) (2005)
Brooks, J. S., Graf, D., Choi, E. S., Almeida, M., Dias, J. C., Henriques, R. T., ...
The Per2M(mnt)2 class of organic conductors exhibit a charge density wave (CDW) ground state below about 12 K, which may be suppressed in magnetic fields of order 20 to 30 T. However, for both cases...
Graf, D., Choi, E. S., Brooks, J. S., Harrison, N., Murata, K., Konoike, T., ...
We have investigated the magnetic field-induced metal-insulator transition in the tau-phase organic conductors, which occurs in fields above 35 T, and below 14 K, by magnetization, thermoelectric,...
Multi-terminal transport through a quantum dot in the Coulomb blockade regime (2004)
Leturcq, R., Graf, D., Ihn, T., Ensslin, K., Driscoll, D. D., Gossard, A. C.
Three terminal tunnelling experiments on quantum dots in the Coulomb blockade regime allow a quantitative determination of the coupling strength of individual quantum states to the leads. Exploiting...
Graf, D., Choi, E. S., Brooks, J. S., Henriques, Rui T., Almeida, M., Matos, M.
We have measured the high field magnetoresistence and magnetization of quasi-one- dimensional (Q1D) organic conductor (Per)2Pt(mnt)2 (where Per = perylene and mnt = maleonitriledithiolate), which has...
Graf, D., Brooks, J. S., Choi, E. S., Uji, S., Dias, J. C., Almeida, M., ...
The charge density wave (CDW) transition temperature in the quasi-one dimensional (Q1D) organic material of (Per)$_2$Au(mnt)$_2$ is relatively low (TCDW = 12 K). Hence in a mean field BCS model, the...
High magnetic field-induced insulating phase in an organic conductor (2002)
Brooks, J. S., Graf, D., Choi, E. S., Balicas, L., Storr, K., Mielke, C. H., ...
We report electrical transport, skin depth, and magnetocaloric measurements in the tau-series of organic conductors at very high magnetic fields. Above 36 T these materials show a magnetic field...
Disorder-driven magnetic field-dependent phases in an organic conductor (2002)
Storr, K., Graf, D., Brooks, J. S., Balicas, L., Mielke, C., Papavassiliou, G. C.
We report inter-plane ($R_{zz}$) electrical transport measurements in the \tp series of organic conductors at very high magnetic fields. In the field range between 36 and 60 T $R_{zz}$ shows a very...
Storr, K., Balicas, L., Brooks, J. S., Graf, D., Papavassiliou, G. C.
We present an electrical transport study of the 2-dimensional (2D) organic conductor tau-(P-(S,S)-DMEDT-TTF)_2(AuBr)_2(AuBr_2)_y (y = 0.75) at low temperatures and high magnetic fields. The...
Balicas, L., Brooks, J. S., Storr, K., Graf, D., Uji, S., Shinagawa, H., ...
Shubnikov-De Haas effect (SdH) effect and angular dependent magnetoresistance oscillations (AMRO) were observed in the organic superconductor: $\kappa$-(BETS)$_2$FeBr$_4$. In contrast to its...
Surface analysis of SI(111) wafers using 2nd-harmonic generation (1994)
Hillrichs, G., Graf, D., Marowsky, G., Roders, O., Schnegg, A., Wagner, P.
Rational primer design greatly improves differential display-PCR (DD-PCR).
Graf, D, Fisher, A G, Merkenschlager, M
Since its conception in 1992, differential display PCR (DD-PCR) has attracted widespread interest. Theoretically an attractive cloning approach, it combines the comparative analysis of several...
Phosphoinositide 3-kinase-dependent Ras activation by tauroursodesoxycholate in rat liver.
Kurz, A K, Block, C, Graf, D, Dahl, S V, Schliess, F, Häussinger, D
Ursodesoxycholic acid, widely used for the treatment of cholestatic liver disease, causes choleretic, anti-apoptotic and immunomodulatory effects. Here the effects on choleresis of its taurine...
Rational primer design greatly improves differential display-PCR (DD-PCR).
Graf, D, Fisher, A G, Merkenschlager, M
Since its conception in 1992, differential display PCR (DD-PCR) has attracted widespread interest. Theoretically an attractive cloning approach, it combines the comparative analysis of several...
Phosphoinositide 3-kinase-dependent Ras activation by tauroursodesoxycholate in rat liver.
Kurz, A K, Block, C, Graf, D, Dahl, S V, Schliess, F, Häussinger, D
Ursodesoxycholic acid, widely used for the treatment of cholestatic liver disease, causes choleretic, anti-apoptotic and immunomodulatory effects. Here the effects on choleresis of its taurine...