Quantum Materials & Nanoelectronics

Research on low-dimensional electron systems at surfaces and interfaces is essential for the development of novel types of nanoscale devices that exploit a range of electronic and magnetic effects. Two outstanding examples are carbon nanostructures (e.g., graphene) and topological insulators (e.g., Bi2Se3), which constitute the focus of our activities. With the aid of spectroscopic methods and electrical measurements, we thoroughly explore the (opto)electronic properties of these materials. In particular, we address their electronic structure in dependence of interfacial doping as well as (covalent or non-covalent) chemical functionalization. Of interest is also the possibility to lift the spin-degeneracy without the use of magnetic fields, as well as the interplay and coexistence of topologically trivial as well as non-trivial states. A further focus is on the synthesis, controlled manipulation and device incorporation of various one- and two-dimensional nanostructures, including inorganic semiconductor nanowires and graphene nanoribbons. Here the aim is to gain a deeper understanding of the basic operation principles of nanoscale photodetectors, photovoltaic devices and field-effect transistors. Along this direction, we probe the local photocurrent response at metal contacts or interfaces between different nanostructures. Another objective is to realize spintronic devices, for instance by implementing strong spin-splitting into a quantum well state, or hybridizing molecular magnets with carbon nanostructures.


Responsible Scientists

Dr. Christian Ast

Dr. Marko Burghard


Team Members

Christian Ast, Marko Burghard, Soudabeh Mashhadi, Junhong Na, Katharina Polyudov, Alessio Scavuzzo, Shweta Sheoran, Andres Topp, Kristina Vaklinova


Key Publications

Soudabeh S. Mashhadi, Dinh Loc Duong, Marko Burghard, and Klaus Kern
Efficient photo-thermoelectric conversion in lateral topological insulator heterojunctions
Nano Lett. 7, 214 (2017)

Roberto Urcuyo, Dinh Loc Duong, Patrick Sailer, Marko Burghard, and Klaus Kern
Hot carrier extraction from multilayer graphene
Nano Lett. 16, 6761 (2016)

Kristina Vaklinova, Alexander Hoyer, Marko Burghard and Klaus Kern
Current-Induced Spin Polarization in Topological Insulatr-Graphene Heterostructures
Nano Lett. 16, 2595 (2016)

Leslie M. Schoop, Mazhar N. Ali, Carola Straßer, Viola Duppel, Stuart S.P. Parkin, Bettina V. Lotsch, and Christian R. Ast
Dirac Cone Protected by Non-Symmorphic Symmetry and 3D Dirac Line Node in ZrSiS
Nature Communications 7, 11696 (2016)
(also: arXiv:1509.00861)

Christian Cervetti, Angelo Rettori, Maria Gloria Pini, Andrea Cornia, Aña Repollés, Fernando Luis, Martin Dressel, Stephan Rauschenbach, Klaus Kern, Marko Burghard, and Lapo Bogani
The classical and quantum dynamics of molecular spins on graphene
Nature Materials 15, 164 (2016)

B.M. Ludbrook, G. Levy, M. Zonno, M. Schneider, D.J. Dvorak, C.N. Veenstra, S. Zhdanovich, D. Wong, P. Dosanjh, C. Straßer, A. Stöhr, S. Forti, C.R. Ast, U. Starke, and A. Damascelli
Evidence for superconductivity in Li-decorated monolayer graphene
PNAS 112, 11795 (2015)

E. C. Peters, A. J. M. Giesbers, M. Burghard, and K. Kern
Scaling in the quantum Hall regime of graphene Corbino devices
Appl. Phys. Lett. 104, 203109 (2014)

P. Gehring, H .M. Benia, Y. Weng, R. Dinnebier, C. R. Ast, M. Burghard, and K. Kern
A natural topological insulator
Nano Lett. 13, 1179 (2013)

P. Gehring, B. F. Gao, M. Burghard, and K. Kern
Growth of high-mobility Bi2Te2Se nanoplatelets on BN sheets by van der Waals epitaxy
Nano Lett. 12, 5137 (2012)

H. M. Benia, C. Lin, K. Kern, and C. R. Ast
Reactive chemical doping of the Bi2Se3 topological insulator
Phys. Rev. Lett. 107, 177602 (2011)

R. S. Sundaram, M. Steiner, H.-Y. Chiu, M. Engel, A. A. Bol, R. Krupke, M. Burghard, K. Kern, and P. Avouris
Weak electronic coupling at the graphene-gold interface
Nano Letters 11, 3833 (2011)

M. Burghard, H. Klauk, and K. Kern,
Carbon-based field effect transistors for nanoelectronics
Adv. Mater. 21, 2586 (2009)

I. Gierz, C. Riedl, U. Starke, C. R. Ast, and K. Kern
Atomic hole doping of graphene
Nano Letters 8, 4603 (2008)

E. J. H. Lee, K. Balasubramanian, R. T. Weitz, M. Burghard, and K. Kern,
Contact and edge effects in graphene devices
Nature Nanotechnology 3, 486 (2008)

C. Gómez-Navarro, R. T. Weitz, A. M. Bittner, M. Scolari, A. Mews, M. Burghard, and K. Kern,
Electronic transport properties of individual chemically reduced graphene oxide sheets
Nano Letters 7, 3499 (2007)

C. R. Ast, J. Henk, A. Ernst, L. Moreschini, M. C. Falub, D. Pacilé, P. Bruno, K. Kern, and M. Grioni
Giant spin splitting through surface alloying
Phys. Rev. Lett. 98, 186807 (2007)

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