Quantum Systems
Quantum phenomena in electron transport in quantum point contacts, quantum wires, quantum rings and quantum wire networks are studied. The quantum structures are made by micro- and nanolithography techniques from semiconductor GaAs- and InAs-based heterostructures hosting low-dimensional high-mobility electron gases.
The effects of electrical fields, low- and high-magnetic fields, temperature and non-thermal equilibrium on charge, spin and thermal transport properties in two, one and zero dimensional structures (2D, 1D, 0D) are investigated.
Of particular interest is the cross-over behaviour from quasi-2D to quasi-1D, quantum coherence and interactions leading to decoherence in extended quasi-1D networks. Materials presently under investigation are GaAs-based and InAs-based heterostructures.
Novel Materials Group
Prof. Dr. Saskia F. Fischer email
Associated researchers
Dr. Olivio Chiatti email
MSc. Birkan Düzel email
Further research topics
Ultra-thin layers | Nanostructures | Novel semiconductor materials
Selected Publications
Excess noise in AlXGa1-XAs/GaAs based quantum rings
C. Riha, S. S. Buchholz, A. D. Wieck, O. Chiatti, D. Reuter, and S. F. Fischer
Appl. Phys. Lett. 117, 063102 (2020).
DOI:10.1063/5.0002247
Short abstract
Thermal energy and charge currents in multi-terminal nanorings
T. Kramer, C. Kreisbeck, C. Riha, O. Chiatti, S. S. Buchholz, A. D. Wieck, D. Reuter, and S. F. Fischer
AIP Advances 6, 065306 (2016).
DOI:10.1063/1.4963812
Short abstract
Heat flow, transport and fluctuations in etched semiconductor quantum wire structures
C. Riha, O. Chiatti, S. S. Buchholz, D. Reuter, A. D. Wieck, and S. F. Fischer
Phys. Status Solidi A 213, 571-581 (2016).
DOI:10.1002/pssa.201532551
Short abstract
Special Issue
Electrical and terahertz magnetospectroscopy studies of laser-patterned micro- and nanostructures on InAs-based heterostructures
O. Chiatti, S. S. Buchholz, C. Heyn, W. Hansen, M. Pakmehr, B. D. McCombe, and S. F. Fischer
Appl. Phys. Lett. 106, 052102 (2015).
DOI: 10.1063/1.4907571
Short abstract
Mode-selected heat flow through a one-dimensional waveguide network
C. Riha, P. Miechowski, S. S. Buchholz, O. Chiatti, A. D. Wieck, D. Reuter, and S. F. Fischer
Appl. Phys. Lett. 106, 083102 (2015).
DOI: 10.1063/1.4908052
Short abstract
THz Magneto-Photoresponse Spectroscopy of Two-Dimensional Electrons in an InAs/InGaAs/InAlAs Inserted-Channel
M. Pakmehr, A. Khaetskii, B. D. McCombe, O. Chiatti, S. F. Fischer, C. Heyn, and W. Hansen
J. Infrared Milli. Terahz. Waves 36, 291 (2015).
DOI: 10.1007/s10762-014-0126-4
Short abstract
Electron waveguide interferometers for spin-dependent transport experiments
O. Chiatti, S. S. Buchholz, U. Kunze, D. Reuter, A. D. Wieck, and S. F. Fischer
Phys. Status Solidi B 251, No. 9, 1753–1763 (2014).
DOI: 10.1002/pssb.201350229
Short abstract
Special Issue "Semiconductor Spintronics"
Noise thermometry in a narrow two-dimensional electron gas and thermal gradients across a quasi-one-dimensional interferometer
S. S. Buchholz, E. Sternemann, O. Chiatti, D. Reuter, A. D. Wieck, and S. F. Fischer
Phys. Rev. B 85, 225301 (2012).
DOI: 10.1103/PhysRevB.85.235301
Many-body enhanced nonlinear conductance resonance in quantum channels
J. E. Han, S. F. Fischer, S. S. Buchholz, U. Kunze, D. Reuter, and A. D. Wieck
Phys. Rev. B 84, 193302 (2011).
DOI: 10.1103/PhysRevB.84.193302
Mode-filtered electron injection into a waveguide interferometer
S. S. Buchholz, U. Kunze, D. Reuter, A. D. Wieck, and S. F. Fischer
Appl. Phys. Lett. 98, 102111 (2011).
DOI: 10.1063/1.3563714
Control of the transmission phase in an asymmetric four-terminal Aharonov-Bohm interferometer
S. S. Buchholz, S. F. Fischer, U. Kunze, M. T. Bell, D. Reuter, and A. D. Wieck
Phys. Rev. B 82, 045432 (2010).
DOI: 10.1103/PhysRevB.82.045432
Aharonov-Bohm phase shift in a multi-terminal asymmetric quantum ring
S. S. Buchholz, S. F. Fischer, U. Kunze, D. Reuter, and A. D. Wieck
Physica E: Low-dimensional Systems and Nanostructures 42, 1099-1102 (2010).
DOI: 10.1016/j.physe.2009.11.123
Nonlocal Aharonov-Bohm conductance oscillations in an asymmetric quantum ring
S. S. Buchholz, S. F. Fischer, U. Kunze, D. Reuter, and A. D. Wieck
Appl. Phys. Lett. 94, 022107 (2009).
DOI: 10.1063/1.3069281
Vertically coupled quantum wires in a longitudinal magnetic field
L. G. Mourokh, A. Y. Smirnov, and S. F. Fischer
Appl. Phys. Lett. 90, 132108-1-3 (2007).
DOI: 10.1063/1.2717147
Energy spectroscopy of controlled coupled quantum-wire states
S. F. Fischer, G. Apetrii, U. Kunze, D. Schuh, and G. Abstreiter
Nature Physics 2, 91-96 (2006).
DOI: 10.1038/nphys205
Tunnel-coupled one-dimensional electron systems with large subband separations
S. F. Fischer, G. Apetrii, U. Kunze, D. Schuh, and G. Abstreiter
Phys. Rev. B 74, 115324_1-7 (2006).
DOI: 10.1103/PhysRevB.74.115324
In-plane tunneling between one- and two-dimensional electron systems
J. L. Deborde, S. F. Fischer, U. Kunze, D. Reuter, and A. D. Wieck
Physica E 34, 522-525 (2006).
DOI: 10.1016/j.physe.2006.03.025
Magnetotransport spectroscopy of spatially coincident coupled electron waveguides
S. F. Fischer, G. Apetrii, U. Kunze, D. Schuh, and G. Abstreiter
Phys. Rev. B 71, 195330 (6 pages) (2005).
DOI: 10.1103/PhysRevB.71.195330
Influence of processing parameters on the transport properties of quantum point contacts fabricated with an atomic force microscope
G. Apetrii, S. F. Fischer, U. Kunze, D. Reuter, and A. D. Wieck
Semicond. Sci. Technol. 17, 735-739 (2002).
DOI: 10.1088/0268-1242/17/7/317
Control of the confining potential in ballistic constriction using a persistent charging effect
S. F. Fischer, S. Skaberna, G. Apetrii, U. Kunze, D. Reuter, and A. D. Wieck
Appl. Phys. Lett. 81 (15), 2779-2781 (2002).
DOI: 10.1063/1.1511278