Publications

Jana M. Meyer, Jan Scharnetzky, Matthias Berl, Werner Wegscheider, Maik Hauser, Werner Dietsche, Kuang-Chung Wang, Gerhard Klimeck, Lars Tiemann, Robert H. Blick
Microwave-induced capacitance resonances and anomalous magnetoresistance in double quantum wells
Journal of Applied Physics 125, 235707 (2019) Magnetotransport measurements on electron bilayer systems under low frequency continuous microwave irradiation reveal an anomalous magnetoresistance behavior. At low total imbalanced carrier densities, pronounced features in the longitudinal and Hall resistance emerge that show a surprisingly strong sensitivity to frequency, microwave power, and density. We suggest its origin to be related to resonantly induced capacitance oscillations of the two-layer system.

Jonas Sichau, Marta Prada, Tim Anlauf, Timothy J. Lyon, Bojan Bosnjak, Lars Tiemann, Robert H. Blick
Resonance Microwave Measurements of an Intrinsic Spin-Orbit Coupling Gap in Graphene: A Possible Indication of a Topological State
Phys. Rev. Lett. 122, 046403 (2019) [arXiv]

Electron spin resonance experiments performed on monolayer graphene at 4.2 K reveal two resonances, i.e., the regular electron Zeeman splitting and a second resonance that persists at zero magnetic field. The latter is related to intrinsic spin orbit coupling that lifts the sublattice degeneracy and (contrary to the idealized picture of graphene) leads to a band gap of approximately 45 µeV. We develop a theoretical model that describes the experimental observations in terms of a topological phase of matter.

A. V. Shchepetilnikov, D. D. Frolov, Yu. A. Nefyodov, I. V. Kukushkin, L. Tiemann, C. Reichl, W. Dietsche, and W. Wegscheider
Spin-orbit coupling effects in the quantum Hall regime probed by electron spin resonance
Phys. Rev. B 98, 241302(R) (2018)

The spin resonance of two-dimensional (2D) electrons confined to a 4.5 nm AlAs quantum well in the regime of the integer quantum Hall effect was studied. The g-factor extracted from the magnetic field position of the spin resonance at a fixed microwave frequency demonstrates a strong nonlinear dependence on the magnetic field. g-factor variations at exactly odd filling factors suggest the entanglement between the spin degree of freedom and the orbital motion of the electrons in the regime of the integer quantum Hall effect. The experimental observations can be reconciled with Dresselhaus-type spin-orbit interaction.

A. R. Khisameeva, A. V. Shchepetilnikov, V. M. Muravev, S. I. Gubarev, D. D. Frolov, Yu. A. Nefyodov, I. V. Kukushkin, C. Reichl, L. Tiemann, W. Dietsche, and W. Wegscheider
Direct observation of a Γ-X energy spectrum transition in narrow AlAs quantum wells
Phys. Rev. B 97, 115308 (2018)

Spectra of magnetoplasma excitations have been investigated in 2DES in AlAs quantum wells (QWs) of different widths. The magnetoplasma spectrum has been found to change profoundly when the quantum well width becomes thinner than 5.5 nm, indicating a drastic change in the conduction electron energy spectrum. The transformation can be interpreted in terms of transition from the in-plane strongly anisotropic Xx-Xy valley occupation to the out-of-plane isotropic Xz valley in the QW plane. Strong enhancement of the cyclotron effective mass over the band value in narrow AlAs QWs is reported.

Clemens Schindler, Christoph Wiegand, Jonas Sichau, Lars Tiemann, Kornelius Nielsch, Robert Zierold, and Robert H. Blick
Strain-induced Dirac state shift in topological insulator Bi2Se3 nanowires
Appl. Phys. Lett. 111, 171601 (2017)

Lev G. Mourokh, Pavel Ivanushkin, Dustin J. Kreft, Hyuncheol Shin, Max Bichler, Werner Wegscheider, Pai Zhao, Lars Tiemann, and Robert H. Blick
Effects of electron confinement on the acoustoelectric current in suspended quantum point contacts
Appl. Phys. Lett. 110, 223102 (2017)

S. Peters, L. Tiemann, C. Reichl, S. Faelt, W. Dietsche, and W. Wegscheider
Improvement of the transport properties of a high-mobility electron system by intentional parallel conduction
Appl. Phys. Lett. 110, 042106 (2017)

A. V. Shchepetilnikov, D. D. Frolov, Yu. A. Nefyodov, I. V. Kukushkin, D. S. Smirnov, Lars Tiemann, C. Reichl, W. Dietsche, and W. Wegscheider
Nuclear magnetic resonance and nuclear spin relaxation in AlAs quantum well probed by ESR
Phys. Rev. B 94, 241302(R) (2016)

Lars Tiemann, Susanne Mueller, Quansheng Wu, Thomas Tschirky, Klaus Ensslin, Werner Wegscheider, Matthias Troyer, Alexey A. Soluyanov, and Thomas Ihn
Impact of strain on the electronic properties of InAs/GaSb quantum well systems
Phys. Rev. B 95, 115108 (2017)

S. Peters, Lars Tiemann, C. Reichl, and W. Wegscheider
Gating versus doping: Quality parameters of two-dimensional electron systems in undoped and doped GaAs/AlGaAs heterostructures
Phys. Rev. B 94, 045304 (2016)

Szymon Hennel, Beat A. Braem, Stephan Baer, Lars Tiemann, Pirouz Sohi, Dominik Wehrli, Christian Reichl, Werner Wegscheider, Clemens Rössler, Thomas Ihn, Klaus Ensslin, Mark S. Rudner, and Bernd Rosenow
Nonlocal Polarization Feedback in a Fractional Quantum Hall Ferromagnet
Phys. Rev. Lett. 116, 136804 (2016)

Matthias Berl, Lars Tiemann, Werner Dietsche, Helmut Karl, Werner Wegscheider
Structured back gates for high-mobility two-dimensional electron systems using oxygen ion implantation
Appl. Phys. Lett. 108, 132102 (2016)

Wang Zhou, H. M. Yoo, S. Prabhu-Gaunkar, L. Tiemann, C. Reichl, W. Wegscheider, and M. Grayson, Phys. Rev. Lett. 115, 186804 (2015)

V.A. V. Shchepetilnikov, Yu. A. Nefyodov, I. V. Kukushkin, L. Tiemann, C. Reichl, W. Dietsche, and W. Wegscheider, Phys. Rev. B 92, 161301(R) (2015)

V. M. Muravev, A. R. Khisameeva, V. N. Belyanin, I. V. Kukushkin, L. Tiemann, C. Reichl, W. Dietsche, and W. Wegscheider, Phys. Rev. B 92, 041303(R) (2015)

T. D. Rhone, L. Tiemann, and K. Muraki, Phys. Rev. B 92, 041301(R) (2015)

L. Tiemann, M. Hauser, and W. Wegscheider, Phys. Rev. Lett. 114, 176804 (2015), [arXiv]

B. Friess, V. Umansky, L. Tiemann, K. von Klitzing, and J. H. Smet, Phys. Rev. Lett. 113, 076803 (2014)

L. Tiemann, T. D. Rhone, N. Shibata, and K. Muraki, Nature Physics 10, 648 (2014), [arXiv]

L. Tiemann, "40. Superfluid Properties of Electron Bilayers," in "Quantum Hall Effects:
Recent Theoretical and Experimental Developments
", Zyun F. Ezawa, Eds. Singapore:
World Scientific Publishing, Third Edition, 2013.

L. Tiemann, G. Gamez, N. Kumada, and K. Muraki, Science 335, 828 (2012), [arXiv]

Y. Yoon, L. Tiemann, S. Schmult, W. Dietsche, and K. von Klitzing, Phys. Rev. Lett. 104, 116802 (2010), [arXiv]

S. Schmult, L. Tiemann, W. Dietsche, and K. von Klitzing, J. Vac. Sci. Technol. B 28, C3C1 (2010)

L. Tiemann, Y. Yoon, W. Dietsche, and K. von Klitzing, Phys. Rev. B 80, 165120 (2009), [arXiv]

L. Tiemann, W. Dietsche, M. Hauser, and K. von Klitzing, Int. J. Mod. Phys. B 23, 2596 (2009)

L. Tiemann, W. Dietsche, M. Hauser, and K. von Klitzing, New Journal of Physics 10, 045018 (2008), [arXiv]

L. Tiemann, J.G.S. Lok, W. Dietsche, K. von Klitzing, K. Muraki, D. Schuh, and W. Wegscheider, Physica E 40, 1034 (2008)

L. Tiemann, J.G.S. Lok, W. Dietsche, K. von Klitzing, K. Muraki, D. Schuh, and W. Wegscheider, Phys. Rev. B 77, 033306 (2008), [arXiv]

R.D. Wiersma, J.G.S. Lok, L. Tiemann, W. Dietsche, K. von Klitzing, W. Wegscheider, and D. Schuh, Int. J. Mod. Phys. B 8-9, 1256 (2007)