Zobrazeno 1 - 10
of 102
pro vyhledávání: '"Heitmann, Detlef"'
Autor:
Kerbst, Jochen, Schwaiger, Stephan, Rottler, Andreas, Koitmäe, Aune, Bröll, Markus, Stemmann, Andrea, Heyn, Christian, Heitmann, Detlef, Mendach, Stefan
We experimentally demonstrate that the transmission though rolled-up metal/semiconductor hyperlenses can be enhanced at desired frequencies utilizing Fabry-P\'erot resonances. By means of finite difference time domain simulations we prove that hyperl
Externí odkaz:
http://arxiv.org/abs/1107.1624
We investigate three-dimensional rolled-up metamaterials containing optically active quantum wells and metal gratings supporting surface plasmon polarition resonances. Finite-difference time-domain simulations show that by matching the surface plasmo
Externí odkaz:
http://arxiv.org/abs/1105.4541
Autor:
Schwaiger, Stephan, Klingbeil, Matthias, Kerbst, Jochen, Rottler, Andreas, Costa, Ricardo, Koitmäe, Aune, Bröll, Markus, Heyn, Christian, Stark, Yuliya, Heitmann, Detlef, Mendach, Stefan
We demonstrate gain in a three-dimensional metal/semiconductor metamaterial by the integration of optically active semiconductor quantum structures. The rolling-up of a metallic structure on top of strained semiconductor layers containing a quantum w
Externí odkaz:
http://arxiv.org/abs/1104.2208
Autor:
Köppen, Tim, Franz, Dennis, Schramm, Andreas, Heyn, Christian, Gutjahr, Johann, Pfannkuche, Daniela, Heitmann, Detlef, Kipp, Tobias
We report on resonant optical spectroscopy of self-assembled InGaAs quantum dots in which the number of electrons can accurately be tuned to N=0,1,2 by an external gate voltage. Polarization, wave vector and magnetic field dependent measurements enab
Externí odkaz:
http://arxiv.org/abs/1012.1762
Autor:
Balhorn, Felix, Mansfeld, Sebastian, Krohn, Andreas, Topp, Jesco, Hansen, Wolfgang, Heitmann, Detlef, Mendach, Stefan
We have investigated spin-wave excitations in rolled-up Permalloy microtubes using microwave absorption spectroscopy. We find a series of quantized azimuthal modes which arise from the constructive interference of Damon-Eshbach type spin waves propag
Externí odkaz:
http://arxiv.org/abs/0908.2082
Publikováno v:
Phys. Rev. B 80, 205320 (2009)
The Teraherz (THz) photoresponse of a two-dimensional electron gas in the quantum Hall regime is investigated. We use a sample structure which is topologically equivalent to a Corbino geometry combined with a cross-gate technique. This quasi-Corbino
Externí odkaz:
http://arxiv.org/abs/0907.0502
Autor:
Krohn, Andreas, Mansfeld, Sebastian, Podbielski, Jan, Topp, Jesco, Hansen, Wolfgang, Heitmann, Detlef, Mendach, Stefan
We report on the propagation of spin waves in permalloy microstripes. By means of scanning Kerr microscopy combined with continuous microwave excitation, we detect the time evolution of spin-wave interference patterns in an external magnetic field. A
Externí odkaz:
http://arxiv.org/abs/0905.2172
Publikováno v:
"Nano-Physics and Bio-Electronics; A new Odyssey", edited by T. Chakraborty, F. Peeters, and U. Sivan, Elsevier Co, ISBN/ISSN: 0-444-50993-3 0444509933 (2002)
We explore the structural changes in charge the density and the electron configuration of quantum dots caused by the presence of other dots in an array, and the interaction of neighboring dots. We discuss what recent measurements and calculation of t
Externí odkaz:
http://arxiv.org/abs/cond-mat/0110323
Publikováno v:
Phys. Rev. B 63, 195303 (2001)
We have investigated the far-infrared response of quantum dots in modulation doped GaAs heterostructures. We observe novel modes at frequencies below the center-of-mass Kohn mode. Comparison with Hartree-RPA calculations show that these modes arise f
Externí odkaz:
http://arxiv.org/abs/cond-mat/0102005
Autor:
Gudmundsson, Vidar, Brataas, Arne, Steinebach, Christoph, Mal'shukov, A. G., Chao, K. A., Heitmann, Detlef
Publikováno v:
Physica Scripta T69, 150 (1997)
We investigate the effects of compressible and incompressible states on the FIR-absorption of quantum wires and dots in a homogeneous perpendicular magnetic field. The electron-electron interaction is treated in the Hartree approximation at a finite
Externí odkaz:
http://arxiv.org/abs/cond-mat/9606187