160 citations · 782 across the 26 of their papers we have counts for
22 papers · 1 filter
Addressing the spin-valley flavors in moir'e mini-bands of MoS2
Chithra H. Sharma, Marta Prada, Jan-Hendrik Schmidt +6
The physics of moir'e superlattices and the resulting formation of mini-bands in van der Waals materials have opened up an exciting new field in condensed matter physics. These sys…
Comment on "Electron spin resonance and collective excitations in magic-angle twisted bilayer graphene"
Lars Tiemann, Marta Prada, Vincent Strenzke +1
This comment pertains the recent manuscript by Morissette {\it et al.} [arXiv:2206.08354v1]. The authors claim to have found signatures of collective excitations in electron spin r…
Nuclear-induced dephasing and signatures of hyperfine effects in isotopically purified C graphene
Vincent Strenzke, Jana M. Meyer, Isabell Grandt-Ionita +6
The hyperfine interaction between the spins of electrons and nuclei is both a blessing and a curse. It can provide a wealth of information when used as an experimental probing tech…
Acoustically Induced Giant Synthetic Hall Voltages in Graphene
Pai Zhao, Chithra H. Sharma, Renrong Liang +7
Any departure from graphene's flatness leads to the emergence of artificial gauge fields that act on the motion of the Dirac fermions through an associated pseudomagnetic field. He…
Electron-Spin-Resonance in a proximity-coupled MoS2/Graphene van-der-Waals heterostructure
Chithra H. Sharma, Pai Zhao, Lars Tiemann +4
Coupling graphene's excellent electron and spin transport properties with higher spin-orbit coupling material allows tackling the hurdle of spin manipulation in graphene, due to th…
Dirac imprints on the -factor anisotropy in graphene
Marta Prada, Lars Tiemann, Jonas Sichau +1
Dirac electrons in graphene are to lowest order spin 1/2 particles, owing to the orbital symmetries at the Fermi level. However, anisotropic corrections in the -factor appear du…
Polarization amplification by spin-doping in nanomagnetic/graphene hybrid systems
Tim Anlauf, Marta Prada, Stefan Freercks +6
The generation of non-equilibrium electron spin polarization, spin transport, and spin detection are fundamental in many quantum devices. We demonstrate that a lattice of magnetic…
Sublattice symmetry breaking and ultra low energy excitations in Graphene-on-hBN Heterostructures
U. R. Singh, M. Prada, V. Strenzke +4
The low-lying states of graphene contain exciting topological properties that depend on the interplay of different symmetry breaking terms. The corresponding energy gaps remained u…
A novel planar back-gate design to control the carrier concentrations in GaAs-based double quantum wells
J. Scharnetzky, J. M. Meyer, M. Berl +4
The precise control of a bilayer system consisting of two adjacent two-dimensional electron gases (2DEG) is demonstrated by using a novel planar back-gate approach based on ion imp…
Acoustically driven Dirac electrons in monolayer graphene
Pai Zhao, Lars Tiemann, Hoc Khiem Trieu +1
We demonstrate the interaction between surface acoustic waves and Dirac electrons in monolayer graphene at low temperatures and high magnetic fields. A metallic interdigitated tran…
Direct observation of energy spectrum transition in narrow AlAs quantum wells
A. R. Khisameeva, A. V. Shchepetilnikov, V. M. Muravev +8
Spectra of magnetoplasma excitations have been investigated in a two-dimensional electron systems in AlAs quantum wells (QWs) of different widths. The magnetoplasma spectrum have b…
Intrinsic spin-orbit coupling gap and the evidence of a topological state in graphene
Jonas Sichau, Marta Prada, Timothy J. Lyon +4
In 2005 Kane & Mele[C. L. Kane and E. J. Mele, Phys. Rev. Lett. 95, 226801 (2005)], predicted that at sufficiently low energy, graphene exhibits a topological state of matter with…
Nuclear magnetic resonance and nuclear spin relaxation in AlAs quantum well probed by ESR
A. V. Shchepetilnikov, D. D. Frolov, Yu. A. Nefyodov +6
The study of nuclear magnetic resonance and nuclear spin-lattice relaxation was conducted in an asymmetrically doped to cm 16 nm AlAs quantum well gr…
Improvement of the transport properties of a high-mobility electron system by intentional parallel conductance
Sebastian Peters, Lars Tiemann, Christian Reichl +3
We present a gating scheme to separate even strong parallel conductance from the magneto-transport signatures and properties of a two-dimensional electron system. By varying the el…
Structured Back Gates for High-Mobility Two-Dimensional Electron Systems Using Oxygen Ion Implantation
Matthias Berl, Lars Tiemann, Werner Dietsche +2
We present a new approach of back gate patterning that is compatible with the requirements of highest mobility molecular beam epitaxy. Contrary to common back gating techniques, ou…
Non-local polarization feedback in a fractional quantum Hall ferromagnet
Szymon Hennel, Beat A. Braem, Stephan Baer +11
In a quantum Hall ferromagnet, the spin polarization of the two-dimensional electron system can be dynamically transferred to nuclear spins in its vicinity through the hyperfine in…
Magnetoplasma excitations of two-dimensional anisotropic heavy fermions in AlAs quantum wells
V. M. Muravev, A. R. Khisameeva, V. N. Belyanin +5
The spectra of plasma and magnetoplasma excitations in a two-dimensional system of anisotropic heavy fermions were investigated for the first time. The spectrum of microwave absorp…
NMR profiling of quantum electron solids in high magnetic fields
L. Tiemann, T. D. Rhone, N. Shibata +1
When the motion of electrons is restricted to a plane under a perpendicular magnetic field B, a variety of quantum phases emerge at low temperatures whose properties are dictated b…
Unraveling the spin polarization of the v = 5/2 fractional quantum Hall state
Lars Tiemann, Gerardo Gamez, Norio Kumada +1
The fractional quantum Hall (FQH) effect at filling factor v = 5/2 has recently come under close scrutiny, as it may possess quasi-particle excitations obeying nonabelian statistic…
Interlayer tunneling in counterflow experiments on the excitonic condensate in quantum Hall bilayers
Y. Yoon, L. Tiemann, S. Schmult +2
The effect of tunneling on the transport properties of} quantum Hall double layers in the regime of the excitonic condensate at total filling factor one is studied in counterflow e…
Dominant parameters for the critical tunneling current in bilayer exciton condensates
L. Tiemann, Y. Yoon, W. Dietsche +2
We will discuss the relevant conditions to observe a critical tunneling current [New J. Phys. 10, 045018 (2008)] in electron double-layer systems at a total filling factor of 1 and…
Exciton condensate at a total filling factor of 1 in Corbino 2D electron bilayers
L. Tiemann, J. G. S. Lok, W. Dietsche +4
Magneto-transport and drag measurements on a quasi-Corbino 2D electron bilayer at the systems total filling factor 1 (v_tot=1) reveal a drag voltage that is equal in magnitude to t…