72 citations · 337 across the 15 of their papers we have counts for
9 papers · 1 filter
Charge carrier density-dependent Raman spectra of graphene encapsulated in hexagonal boron nitride
Jens Sonntag, Kenji Watanabe, Takashi Taniguchi +2
We present low-temperature Raman measurements on gate tunable graphene encapsulated in hexagonal boron nitride, which allows to study in detail the Raman G and 2D mode frequencies…
Raman imaging of twist angle variations in twisted bilayer graphene at intermediate angles
A. Schäpers, J. Sonntag, L. Valerius +9
Van der Waals layered materials with well-defined twist angles between the crystal lattices of individual layers have attracted increasing attention due to the emergence of unexpec…
Engineering tunable strain fields in suspended graphene by microelectromechanical systems
Jens Sonntag, Matthias Goldsche, Tymofiy Khodkov +5
Here, we present a micro-electromechanical system (MEMS) for the investigation of the electromechanical coupling in graphene and potentially related 2D materials. Key innovations o…
Electrical Control over Phonon Polarization in Strained Graphene
Jens Sonntag, Sven Reichardt, Bernd Beschoten +1
We explore the tunability of the phonon polarization in suspended uniaxially strained graphene by magneto-phonon resonances. The uniaxial strain lifts the degeneracy of the LO and…
Tunable coupling of two mechanical resonators by a graphene membrane
G. J. Verbiest, M. Goldsche, J. Sonntag +4
Coupled nanomechanical resonators are interesting for both fundamental studies and practical applications as they offer rich and tunable oscillation dynamics. At present, the mecha…
Excellent electronic transport in heterostructures of graphene and monoisotopic boron-nitride grown at atmospheric pressure
J. Sonntag, J. Li, A. Plaud +4
Hexagonal boron nitride (BN), one of the very few layered insulators, plays a crucial role in 2D materials research. In particular, BN grown with a high pressure technique has prov…
Impact of Many-Body Effects on Landau Levels in Graphene
J. Sonntag, S. Reichardt, L. Wirtz +4
We present magneto-Raman spectroscopy measurements on suspended graphene to investigate the charge carrier density-dependent electron-electron interaction in the presence of Landau…
Line Shape of the Raman 2D Peak of Graphene in Van Der Waals Heterostructures
Christoph Neumann, Luca Banszerus, Michael Schmitz +6
The Raman 2D line of graphene is widely used for device characterization and during device fabrication as it contains valuable information on e.g. the direction and magnitude of me…
Giant magneto-photoelectric effect in suspended graphene
Jens Sonntag, Annika Kurzmann, Martin Geller +3
We study the optical response of a suspended graphene field-effect transistor in magnetic fields of up to 9 T (quantum Hall regime). With an illumination power of only 3 μW, we mea…