Klos, J. W., Shylau, A. A., Zozoulenko, I. V., Xu, Hengyi, Heinzel, T.
We study the effects of the long-range disorder potential and warping on the conductivity and mobility of graphene ribbons using the Landauer formalism and the tight-binding p-orbital Hamiltonian. We...
Piezoresistance in chemically synthesized polypyrrole thin films (2009)
Barnoss, S., Shanak, H., Bufon, C. Bof, Heinzel, T.
The resistance of chemically synthesized polypyrrole (PPy) thin films is investigated as a function of the pressure of various gases as well as of the film thickness. A physical, piezoresistive...
Quantized magnetic confinement in quantum wires (2009)
Tarasov, A., Hugger, S., Xu, Hengyi, Cerchez, M., Heinzel, T., Zozoulenko, I. V., ...
Ballistic quantum wires are exposed to longitudinal profiles of perpendicular magnetic fields composed of a spike (magnetic barrier) and a homogeneous part. An asymmetric magnetoconductance peak as a...
Edge disorder and localization regimes in bilayer graphene nanoribbons (2009)
Xu, Hengyi, Heinzel, T., Zozoulenko, I. V.
A theoretical study of the magnetoelectronic properties of zigzag and armchair bilayer graphene nanoribbons (BGNs) is presented. Using the recursive Green's function method, we study the band...
Hugger, S., Heinzel, T., Thurn-Albrecht, T.
A poly(styrene-block-methylmethacrylate) diblock copolymer in the hexagonal cylindrical phase has been used as a mask for preparing a periodic gate on top of a Ga[Al]As-heterostructure. A...
Edge disorder induced Anderson localization and conduction gap in graphene nanoribbons (2008)
Evaldsson, M., Zozoulenko, I. V., Xu, Hengyi, Heinzel, T.
We study the effect of the edge disorder on the conductance of the graphene nanoribbons (GNRs). We find that only very modest edge disorder is sufficient to induce the conduction energy gap in the...
Magnetic barrier induced conductance fluctuations in quantum wires (2008)
Hugger, S., Xu, Hengyi, Tarasov, A., Cerchez, M., Heinzel, T., Zozoulenko, I. V., ...
Quasi-ballistic semiconductor quantum wires are exposed to localized perpendicular magnetic fields, also known as magnetic barriers. Pronounced, reproducible conductance fluctuations as a function of...
Magnetoresistance of antidot lattices with grain boundaries (2008)
Klinkhammer, S., Xu, Hengyi, Heinzel, T., Gennser, U., Faini, G., Ulysse, C., ...
The magnetotransport properties of antidot lattices containing artificially designed grain boundaries have been measured. We find that the grain boundaries broaden the commensurability resonances and...
Magnetic barriers in graphene nanoribbons (2008)
Xu, Hengyi, Heinzel, T., Evaldsson, M., Zozoulenko, I. V.
A theoretical study of the transport properties of zigzag and armchair graphene nanoribbons with a magnetic barrier on top is presented. The magnetic barrier modifies the energy spectrum of the...
Magnetic-barrier-induced conductance fluctuations in quantum wires (2008)
Hugger, S., Xu, H.Y., Tarasov, A., Cerchez, M., Heinzel, T., Zozoulenko, I.V, ...
Quasiballistic semiconductor quantum wires are exposed to localized perpendicular magnetic fields, also known as magnetic barriers. Pronounced, reproducible conductance fluctuations as a function of...
Hugger, S., Cerchez, M., Xu, H., Heinzel, T.
Magnetic barriers in two-dimensional electron gases are shifted in B space by homogeneous, perpendicular magnetic fields. The magnetoresistance across the barrier shows a characteristic asymmetric...
Transport properties of chemically synthesized polypyrrole thin films (2007)
The electronic transport in polypyrrole thin films synthesized chemically from the vapor phase is studied as a function of temperature as well as of electric and magnetic fields. We find distinct...
Resonant reflection at magnetic barriers in quantum wires (2007)
Xu, Hengyi, Heinzel, T., Evaldsson, M., Ihnatsenka, S., Zozoulenko, I. V.
The conductance of a quantum wire containing a single magnetic barrier is studied numerically by means of the recursive Greens function technique. For sufficiently strong and localized barriers, Fano...
Effect of edge transmission and elastic scattering on the resistance of magnetic barriers (2007)
Cerchez, M., Hugger, S., Heinzel, T., Schulz, N.
Strong magnetic barriers are defined in two-dimensional electron gases by magnetizing dysprosium ferromagnetic platelets on top of a Ga[Al]As heterostructure. A small resistance across the barrier is...
Cerchez, M., Hugger, S., Heinzel, T., Schulz, N.
Strong magnetic barriers are defined in two-dimensional electron gases by magnetizing dysprosium ferromagnetic platelets on top of a Ga[Al]As heterostructure. A small resistance across the barrier is...
Cerchez, M., Hugger, S., Heinzel, T., Schulz, N.
Strong magnetic barriers are defined in two-dimensional electron gases by magnetizing dysprosium ferromagnetic platelets on top of a Ga[Al]As heterostructure. A small resistance across the barrier is...
Commensurability Effects in Hexagonal Antidot Lattices with Large Antidot Diameters (2005)
Meckler, S., Heinzel, T., Cavanna, A., Faini, G., Gennser, U., Mailly, D.
The observation of a novel type of commensurability resonance in two-dimensional, hexagonal antidot lattices is reported. These resonances have a classical character and occur at magnetic fields...
The HDAC inhibitor valproic acid selectively induces proteasomal degradation of HDAC2. (2003)
Krämer, O.H., Zhu, P., Ostendorff, H.P., Golebiewski, M., Tiefenbach, J., Peters, M.A., ...
Keystone Meeting 'Enzymology of Chromatine and Transcription', Santa Fe, N.M., March 10-13, 2003
Krämer, O.H., Zhu, P., Ostendorff, H.P., Golebiewski, M., Tiefenbach, J., Peters, M.A., ...
The EMBO Journal, 22(2003) S.3411-20
Göttlicher, M., Minucci, S., Zhu, P., Krämer, O.H., Schimpf, A., Giavara, S., ...
The EMBO Journal, 20(2001) S.6969-78
The teratogen valproic acid is a selective inhibitor of a subset of histone deacetylases. (2002)
Zhu, P., Krämer, O.H., Heinzel, T., Göttlicher, M.
43.Frühjahrstagung der Deutschen Gesellschaft für experimentelle und klinische Pharmakologie und Toxikologie (DGPT), Mainz, 12.-14.März 2002
Göttlicher, M., Minucci, S., Zhu, P., Krämer, O.H., Schimpf, A., Giavara, S., ...
43.Frühjahrstagung der Deutschen Gesellschaft für experimentelle und klinische Pharmakologie und Toxikologie (DGPT), Mainz, 12.-14.März 2002
Göttlicher, M., Minucci, S., Zhu, P., Krämer, O.H., Schimpf, A., Giavara, S., ...
93rd Annual Meeting of the American Association for Cancer Research, San Francisco, Calif., April 6-10, 2002
Göttlicher, M., Zhu, P., Werling, U., Sleeman, J., Krämer, O., Heinzel, T.
Nachrichten - Forschungszentrum Karlsruhe, 34(2002) S.69-74
Transport signatures of correlated disorder in a two-dimensional electron gas (2001)
Heinzel, T., Jaeggi, R. D., Ribeiro, E., Waldkirch, M. V., Ensslin, K., Ulloa, S. E., ...
We report electronic transport measurements on two-dimensional electron gases in a Ga[Al]As heterostructure with an embedded layer of InAs self-assembled quantum dots. At high InAs dot densities,...
Energy spectra of quantum rings (2001)
Fuhrer, A., Luescher, S., Ihn, T., Heinzel, T., Ensslin, K., Wegscheider, W., ...
Ring geometries have fascinated experimental and theoretical physicists over many years. Open rings connected to leads allow the observation of the Aharonov-Bohm effect, a paradigm of quantum...
Electronic properties of antidot lattices fabricated by atomic force lithography (2001)
Dorn, A., Fuhrer, A., Ihn, T., Heinzel, T., Ensslin, K., Wegscheider, W., ...
Antidot lattices were fabricated by atomic force lithography using local oxidation. High quality finite 20 x20 lattices are demonstrated with periods of 300 nm. The low temperature magnetoresistance...
Analysis of the resistance in p-SiGe over a wide temperature range (2001)
Senz, V., Ihn, T., Heinzel, T., Ensslin, K., Dehlinger, G., Grützmacher, D., ...
The temperature dependence of a system exhibiting a `metal-insulator transition in two dimensions at zero magnetic field' (MIT) is studied up to 90K. Using a classical scattering model we are able to...
Shot noise by quantum scattering in chaotic cavities (2001)
Oberholzer, Stefan, Sukhorukov, Eugene V., Strunk, Christoph, Schonenberger, Christian, Heinzel, T., Holland, M.
We have experimentally studied shot noise of chaotic cavities defined by two quantum point contacts in series. The cavity noise is determined as (1/4)2e[1] in agreement with theory and can be well...
The Hanbury Brown and Twiss Experiment with Fermions (2001)
Oberholzer, S., Henny, M., Strunk, C., Schonenberger, C., Heinzel, T., Ensslin, K., ...
We realized an equivalent Hanbury Brown and Twiss experiment for a beam of electrons in a two dimensional electron gas in the quantum Hall regime. A metallic split gate serves as a tunable beam...
Shot Noise by Quantum Scattering in Chaotic Cavities (2001)
Heinzel, T., Holland, M., Oberholzer, S., Schönenberger, C., Strunk, C., Sukhorukov, E. V.
Signatures of Spin Pairing in Chaotic Quantum Dots (2001)
Bichler, M., Ensslin, K., Heinzel, T., Lüscher, S., Wegscheider, W.
Histone deacetylase as a therapeutic target. (2001)
Krämer, O.H., Göttlicher, M., Heinzel, T.
Trends in Endocrinology and Metabolism, 12(2001) S.294-300
Senz, V., Heinzel, T., Ihn, T., Lindemann, S., Held, R., Ensslin, K., ...
The temperature dependence of the conductance of a quantum point contact has been measured. The conductance as a function of the Fermi energy shows temperature-independent fixed points, located at...
Transport properties of quantum dots with hard walls (2000)
Fuhrer, A., Luescher, S., Heinzel, T., Ensslin, K., Wegscheider, W., Bichler, M.
Quantum dots are fabricated in a Ga[Al]As-heterostructure by local oxidation with an atomic force microscope. This technique, in combination with top gate voltages, allows us to generate steep walls...
Single hole transistor in a p-Si/SiGe quantum well (2000)
Doetsch, U., Gennser, U., Heinzel, T., Luescher, S., David, C., Dehlinger, G., ...
A single hole transistor is patterned in a p-Si/SiGe quantum well by applying voltages to nanostructured top gate electrodes. Gating is achieved by oxidizing the etched semiconductor surface and the...
Shot Noise by Quantum Scattering in Chaotic Cavities (2000)
Oberholzer, S., Sukhorukov, E. V., Strunk, C., Schonenberger, C., Heinzel, T., Ensslin, K., ...
We have experimentally studied shot noise of chaotic cavities defined by two quantum point contacts in series. The cavity noise is determined as 1/4*2e|I| in agreement with theory and can be well...
Senz, V., Ihn, T., Heinzel, T., Ensslin, K., Dehlinger, G., Grutzmacher, D., ...
We find that temperature dependent screening can quantitatively explain the metallic behaviour of the resistivity on the metallic side of the so-called metal-insulator transition in p-SiGe....
Signatures of spin pairing in a quantum dot in the Coulomb blockade regime (2000)
Luescher, S., Heinzel, T., Ensslin, K., Wegscheider, W., Bichler, M.
Coulomb blockade resonances are measured in a GaAs quantum dot in which both shape deformations and interactions are small. The parametric evolution of the Coulomb blockade peaks shows a pronounced...
Ribeiro,E., Jäggi,R., Heinzel,T., Ensslin,K., Medeiros-Ribeiro,G., Petroff,P. M.
We report the observation of a metal-insulator transition in zero magnetic eld in a two dimensional electron gas under the influence of a plane of InAs self-assembled quantum dots located at 30 Å...
Coexistence of Weak Localization and a Metallic Phase in Si/SiGe Quantum Wells (1999)
Senz, V., Heinzel, T., Ihn, T., Ensslin, K., Dehlinger, G., Gruetzmacher, D., ...
Magnetoresistivity measurements on p-type Si/SiGe quantum wells reveal the coexistence of a metallic behavior and weak localization. Deep in the metallic regime, pronounced weak localization reduces...
Heinzel, T., Salis, G., Held, R., Luescher, S., Ensslin, K., Wegscheider, W., ...
A quantum wire is spatially displaced by suitable electric fields with respect to the scatterers inside a semiconductor crystal. As a function of the wire position, the low-temperature resistance...
In-plane gate single-electron transistor in Ga[Al]As fabricated by scanning probe lithography (1999)
Luescher, S., Fuhrer, A., Held, R., Heinzel, T., Ensslin, K., Wegscheider, W.
A single-electron transistor has been realized in a Ga[Al]As heterostructure by oxidizing lines in the GaAs cap layer with an atomic force microscope. The oxide lines define the boundaries of the...
Furlan, M., Heinzel, T., Jeanneret, B., Lotkhov, S. V., Ensslin, K.
The distribution of nearest-neighbour spacings of Coulomb blockade oscillation peaks in normal conducting aluminum single electron transistors is found to be non-Gaussian. A pronounced tail to...
The Fermionic Hanbury Brown and Twiss Experiment (1999)
Henny, M., Oberholzer, Stefan, Strunk, Christoph, Heinzel, T., Ennslin, K., Holland, M.
A Hanbury Brown and Twiss experiment for a beam of electrons has been realized in a two-dimensional electron gas in the quantum Hall regime. A metallic split gate serves as a tunable beam splitter to...
Metal-Insulator Transition in a 2-Dimensional System with an Easy Spin Axis (1999)
Senz, V., Doetsch, U., Gennser, U., Ihn, T., Heinzel, T., Ensslin, K., ...
The low-temperature resistivity of a SiGe 2-dimensional hole gas has been studied using the gate controlled carrier density as a parameter. A metal-insulator transition is seen both in the...
Mode Spectroscopy and Level Coupling in Ballistic Electron Waveguides (1999)
Salis, G., Heinzel, T., Ensslin, K., Homan, O. J., Bachtold, W., Maranowski, K., ...
A tunable quantum point contact with modes occupied in both transverse directions is studied by magnetotransport experiments. We use conductance quantization of the one-dimensional subbands as a tool...
Variation of elastic scattering across a quantum well (1998)
Salis, G., Wirth, P., Heinzel, T., Ihn, T., Ensslin, K., Maranwoski, K., ...
The Drude scattering times of electrons in two subbands of a parabolic quantum well have been studied at constant electron sheet density and different positions of the electron distribution along the...
Acremann, Y., Heinzel, T., Gini, K. Ensslin E., Melchior, H., Holland, M.
The equilibration length between spin-polarized edge states in the Quantum Hall regime is measured as a function of a gate voltage applied to an electrode on top of the edge channels. Reproducible...
Ribeiro, E., Jaeggi, R., Heinzel, T., Ensslin, K., Medeiros-Ribeiro, G., Petroff, P. M.
A metal-insulator transition in two-dimensional electron gases at B=0 is found in Ga(Al)As heterostructures, where a high density of self-assembled InAs quantum dots is incorporated just 3 nm below...
Statistics of conductance oscillations of a quantum dot in the Coulomb-blockade regime (1997)
Simmel, F., Heinzel, T., Wharam, D. A.
The fluctuations and the distribution of the conductance peak spacings of a quantum dot in the Coulomb-blockade regime are studied and compared with the predictions of random matrix theory (RMT). The...
Bach, I, Rhodes, S J, Pearse, R V, Heinzel, T, Gloss, B, Scully, K M, ...
A pituitary LIM homeodomain factor, P-Lim, is expressed as Rathke's pouch forms and as specific pituitary cell phenotypes are established, suggesting functional roles throughout pituitary...
Bach, I, Rhodes, S J, Pearse, R V, Heinzel, T, Gloss, B, Scully, K M, ...
A pituitary LIM homeodomain factor, P-Lim, is expressed as Rathke's pouch forms and as specific pituitary cell phenotypes are established, suggesting functional roles throughout pituitary...
Atmaca, A, Al-Batran, S-E, Maurer, A, Neumann, A, Heinzel, T, Hentsch, B, ...
Altered histone deacetylase (HDAC) activity has been identified in several types of cancer. This study was designed to determine the safety and maximum tolerated dose (MTD) of valproic acid (VPA) as...