Piot, B. A., Maude, D. K., Gennser, U., Cavanna, A., Mailly, D.
The magnetoresistance of a low carrier density, disordered GaAs based two-dimensional (2D) electron gas has been measured in parallel magnetic fields up to 32 T. The feature in the resistance...
Non-Equilibrium Edge Channel Spectroscopy in the Integer Quantum Hall Regime (2009)
Altimiras, C., Sueur, H. Le, Gennser, U., Cavanna, A., Mailly, D., Pierre, F.
Heat transport has large potentialities to unveil new physics in mesoscopic systems. A striking illustration is the integer quantum Hall regime, where the robustness of Hall currents limits...
Tuning decoherence with a voltage probe (2009)
Roulleau, P., Portier, F., Roche, P., Cavanna, A., Faini, G., Gennser, U., ...
We present an experiment where we tune the decoherence in a quantum interferometer using one of the simplest object available in the physic of quantum conductors : an ohmic contact. For that purpose,...
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...
Noise dephasing in the edge states of the Integer Quantum Hall regime (2008)
Roulleau, P., Portier, F., Roche, P., Cavanna, A., Faini, G., Gennser, U., ...
An electronic Mach Zehnder interferometer is used in the integer quantum hall regime at filling factor 2, to study the dephasing of the interferences. This is found to be induced by the electrical...
F. Coppinger, J. Genoe, L. B. Rigal, D. K. Maude, U. Gennser, J. C. Portal, ...
Using low temperature magnetotransport techniques we demonstrate that the electrical transport is phase coherent in a GaAs matrix containing self organising ErAs quantum dots and wires of the order...
Experimental Test of the Dynamical Coulomb Blockade Theory for Short Coherent Conductors (2007)
Altimiras, C., Gennser, U., Cavanna, A., Mailly, D., Pierre, F.
We observed the recently predicted quantum suppression of dynamical Coulomb blockade on short coherent conductors by measuring the conductance of a quantum point contact embedded in a tunable on-chip...
Direct measurement of the coherence length of edge states in the Integer Quantum Hall Regime (2007)
Roulleau, P., Portier, F., Roche, P., Cavanna, A., Faini, G., Gennser, U., ...
We have determined the finite temperature coherence length of edge states in the Integer Quantum Hall Effect (IQHE) regime. This was realized by measuring the visibility of electronic Mach-Zehnder...
Piot, B. A., Maude, D. K., Henini, M., Wasilewski, Z. R., Gupta, J. A., Friedland, K. J., ...
In a recent paper [B. A. Piot et al., Phys. Rev. B 72, 245325 (2005)], we have shown that the lifting of the electron spin degeneracy in the integer quantum Hall effect at high filling factors should...
Finite bias visibility of the electronic Mach-Zehnder interferometer (2007)
Roulleau, Preden, Portier, F., Glattli, D. C., Roche, P., Cavanna, A., Gaini, G., ...
We present an original statistical method to measure the visibility of interferences in an electronic Mach-Zehnder interferometer in the presence of low frequency fluctuations. The visibility...
Magnetic field asymmetry of mesocopic dc rectification in Aharonov Bohm rings (2006)
Angers, L., Zakka-Bajjani, E., Deblock, R., Gueron, S., Cavanna, A., Gennser, U., ...
Fundamental Casimir-Onsager symmetry rules for linear response do not apply to non linear transport. This motivates the investigation of nonlinear dc conductance of mesoscopic GaAs/GaAlAs rings in a...
Jouault, B., Gryglas, M., Faini, G., Gennser, U., Cavanna, A., Baj, M., ...
A single impurity is used to probe the local density of states of a two-dimensional electron gas (2DEG) in a resonant tunneling experiment. The studies have been performed in the GaAs/AlAs/GaAs...
Spectroscopy of a single Si donor by the resonant tunnelling experiment (2006)
Baj, M., Gryglas, M., Jouault, B., Maude, D., Faini, G., Gennser, U., ...
Resonant tunnelling via single impurities placed in a single barrier was experimentally studied. The typically observed structures in the current-voltage characteristics seem to be paired. Such a...
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...
Total Angular Momentum Conservation During Tunnelling through Semiconductor Barriers (2005)
Gennser, U., Scheinert, M., Diehl, L., Tsujino, S., Borak, A., Falub, C. V., ...
We have investigated the electrical transport through strained p-Si/Si_{1-x}Ge_x double-barrier resonant tunnelling diodes. The confinement shift for diodes with different well width, the shift due...
Matériaux de basse dimensionnalité : La transition métal-isolant en dimension deux (2002)
Peut-on réaliser des métaux à deux dimensions ? Jusqu'en 1994, il semblait théoriquement bien établi que non~: en mécanique quantique, un électron placé dans un milieu désordonné plan ne...
Matériaux de basse dimensionnalité : La transition métal-isolant en dimension deux (2002)
Peut-on réaliser des métaux à deux dimensions ? Jusqu'en 1994, il semblait théoriquement bien établi que non~: en mécanique quantique, un électron placé dans un milieu désordonné plan ne...
Heating of Two-Dimensional Holes in SiGe and the B = 0 Metal-Insulator Transition (2001)
Leturcq, R., L'Hote, D., Tourbot, R., Senz, V., Gennser, U., Ihn, T., ...
We study the resistivity vs. electric field dependence $\rho(E)$ of a 2D hole system in SiGe close to the B=0 metal-insulator transition. Using $\rho$ as a ``thermometer'' to obtain the effective...
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...
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...
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....
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...
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...