References of "Stampfer, Christoph"
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See detailImpact of many-body effects on Landau levels in graphene
Sonntag, Jens; Reichardt, Sven UL; Wirtz, Ludger UL et al

in Physical Review Letters (2018), 120(18), 187701

We present magneto-Raman spectroscopy measurements on suspended graphene to investigate the charge carrier density-dependent electron-electron interaction in the presence of Landau levels. Utilizing gate ... [more ▼]

We present magneto-Raman spectroscopy measurements on suspended graphene to investigate the charge carrier density-dependent electron-electron interaction in the presence of Landau levels. Utilizing gate-tunable magnetophonon resonances, we extract the charge carrier density dependence of the Landau level transition energies and the associated effective Fermi velocity vF. In contrast to the logarithmic divergence of vF at zero magnetic field, we find a piecewise linear scaling of vF as a function of the charge carrier density, due to a magnetic-field-induced suppression of the long-range Coulomb interaction. We quantitatively confirm our experimental findings by performing tight-binding calculations on the level of the Hartree-Fock approximation, which also allow us to estimate an excitonic binding energy of ≈6  meV contained in the experimentally extracted Landau level transitions energies. [less ▲]

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See detailTailoring mechanically tunable strain fields in graphene
Goldsche, Matthias; Sonntag, Jens; Khodkov, Tymofiy et al

in Nano Letters (2018), 18(3), 1707--1713

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See detailLine shape of the Raman 2D peak of graphene in van der Waals heterostructures
Neumann, Christoph; Banszerus, Luca; Schmitz, Michael et al

in Physica Status Solidi B. Basic Research (2016), 253(12), 2326--2330

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See detailModeling charge relaxation in graphene quantum dots induced by electron-phonon interaction
Reichardt, Sven UL; Stampfer, Christoph

in Physical Review B (2016), 93(24), 245423

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See detailCorrespondence: On the nature of strong piezoelectricity in graphene on SiO2
Stampfer, Christoph; Reichardt, Sven UL

in Nature Communications (2016), 7

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See detailSpatial control of laser-induced doping profiles in graphene on hexagonal boron nitride
Neumann, Christoph; Rizzi, Leo; Reichardt, Sven UL et al

in ACS Applied Materials and Interfaces (2016), 8(14), 9377-9383

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See detailProbing electronic lifetimes and phonon anharmonicities in high-quality chemical vapor deposited graphene by magneto-Raman spectroscopy
Neumann, Christoph; Halpaap, Donatus; Reichardt, Sven UL et al

in Applied Physics Letters (2015), 107(23), 233105

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See detailRaman spectroscopy as probe of nanometre-scale strain variations in graphene
Neumann, Christoph; Reichardt, Sven UL; Venezuela, Pedro et al

Poster (2015, July 14)

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See detailLow B field magneto-phonon resonances in single-layer and bilayer graphene
Neumann, Christoph; Reichardt, Sven UL; Drögeler, Marc et al

in Nano Letters (2015), 15(3), 1547--1552

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See detailRelaxation times and electron-phonon interaction in graphene quantum dots
Reichardt, Sven UL; Volk, Christian; Neumann, Christoph et al

Poster (2014, November 07)

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See detailRaman spectroscopy on mechanically exfoliated pristine graphene ribbons
Terrés, Bernat; Reichardt, Sven UL; Neumann, Christoph et al

in Physica Status Solidi B. Basic Research (2014), 251(12), 2551--2555

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See detailImpact of thermal annealing on graphene devices encapsulated in hexagonal boron nitride
Engels, Stephan; Terrés, Bernat; Klein, Felix et al

in Physica Status Solidi B. Basic Research (2014), 251(12), 2545--2550

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See detailRelaxation times and electron-phonon interaction in graphene quantum dots
Reichardt, Sven UL; Volk, Christian; Neumann, Christoph et al

Poster (2013, May 23)

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See detailTransport through open quantum dots: Making semiclassics quantitative
Brezinova, Iva; Wirtz, Ludger UL; Rotter, Stefan et al

in Physical Review. B, Condensed Matter and Materials Physics (2010), 81(12),

We investigate electron transport through clean open quantum dots (quantum billiards). We present a semiclassical theory that allows to accurately reproduce quantum-transport calculations. Quantitative ... [more ▼]

We investigate electron transport through clean open quantum dots (quantum billiards). We present a semiclassical theory that allows to accurately reproduce quantum-transport calculations. Quantitative agreement is reached for individual energy-dependent and magnetic field dependent elements of the scattering matrix. Two key ingredients are essential: (i) inclusion of pseudopaths which have the topology of linked classical paths resulting from diffraction in addition to classical paths and (ii) a high-level approximation to diffractive scattering. Within this framework of the pseudopath semiclassical approximation (PSCA), typical shortcomings of semiclassical theories such as violation of the anticorrelation between reflection and transmission and the overestimation of conductance fluctuations are overcome. Beyond its predictive capabilities the PSCA provides deeper insights into the quantum-to-classical crossover. [less ▲]

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See detailDiffractive paths for weak localization in quantum billiards
Brezinova, Iva; Stampfer, Christoph; Wirtz, Ludger UL et al

in Physical Review B (2008), 77(16),

We study the weak-localization effect in quantum transport through a clean ballistic cavity with regular classical dynamics. We address the question which paths account for the suppression of conductance ... [more ▼]

We study the weak-localization effect in quantum transport through a clean ballistic cavity with regular classical dynamics. We address the question which paths account for the suppression of conductance through a system where disorder and chaos are absent. By exploiting both quantum and semiclassical methods, we unambiguously identify paths that are diffractively backscattered into the cavity (when approaching the lead mouths from the cavity interior) to play a key role. Diffractive scattering couples transmitted and reflected paths and is thus essential to reproduce the weak-localization peak in reflection and the corresponding antipeak in transmission. A comparison of semiclassical calculations featuring these diffractive paths yields good agreement with full quantum calculations and experimental data. Our theory provides system-specific predictions for the quantum regime of few open lead modes and can be expected to be relevant also for mixed as well as chaotic systems. [less ▲]

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See detailRaman spectroscopy on single- and few-layer graphene
Graf, Davy; Molitor, Francoise; Ensslin, Klaus et al

in AIP Conference Proceedings (2007), 893

We report on Raman measurements of single- and few-layer graphene flakes. Raman mapping in combination with scanning force microscopy allows us to locally relate the thickness of the graphite flake with ... [more ▼]

We report on Raman measurements of single- and few-layer graphene flakes. Raman mapping in combination with scanning force microscopy allows us to locally relate the thickness of the graphite flake with the spectral properties. It turns out that the width of the D' line is highly sensitive to the transition from single- to double-layer graphene. The defect-induced D line is found to be most prominent at steps between sections of different height and along the edge of the graphite flake. [less ▲]

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