Zobrazeno 1 - 10
of 80
pro vyhledávání: '"F J Ahlers"'
Autor:
F. J. Ahlers
Introductory presentation on data managment requirements and procedures in GIQS
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::54391ccb5f846e7421491d3bd525c3c6
Publikováno v:
2018 Conference on Precision Electromagnetic Measurements (CPEM 2018).
This paper describes the characterization of a quantum voltage noise source (QVNS) based on pulse-driven Josephson-arrays for frequencies up to 200 kHz. The QVNS synthesizes a voltage noise reference which is used to calibrate the electronics of a Jo
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::242d2ef4228759df0b8515750c712c61
https://doi.org/10.1109/cpem.2018.8500838
https://doi.org/10.1109/cpem.2018.8500838
Autor:
Tobias Bergsten, Frank Hohls, C.-C. Kalmbach, Rolf J. Haug, F. J. Ahlers, Klaus Pierz, A. Müller, Mattias Kruskopf, Jürgen Schurr
Publikováno v:
Physical Review B. 96
We investigate the properties of the magnetocapacitance and dissipation factor of epitaxial graphene Hall bars with different electrode configurations to gain insight into the underlying physical mechanisms. The dependence of magnetocapacitance and d
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::a77b5fd7a0f5ac6b1726f1e7a0a9ff68
https://doi.org/10.1103/physrevb.96.155443
https://doi.org/10.1103/physrevb.96.155443
Publikováno v:
Metrologia. 51:235-242
We present a simple and accurate coaxial bridge capable of measuring the magnetocapacitance and the associated loss factor of a quantum Hall effect device, with and without an external Hall current—a situation where commercial instruments are limit
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::960986d8fa3384ee6cff7e1f69c87e46
https://doi.org/10.1088/0026-1394/51/3/235
https://doi.org/10.1088/0026-1394/51/3/235
Publikováno v:
IEEE Transactions on Instrumentation and Measurement. 62:1634-1639
We present the combination of two Josephson waveform synthesizers to generate waveforms with low harmonic distortion [below $-$ 110 dBc (carrier)] and amplitudes above the 1-V level. Fast and flexible code programming enables pulse-driven Josephson a
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::f63da0eddf39296f56638b95c1ecef3a
https://doi.org/10.1109/tim.2013.2238433
https://doi.org/10.1109/tim.2013.2238433
Publikováno v:
2016 Conference on Precision Electromagnetic Measurements (CPEM 2016).
Quantum Hall resistors made from epitaxial graphene measured with alternating current exhibit an unusual negative frequency dependence. To test the hypothesis that parasitic capacitances between contact pads cause this effect, we studied capacitance
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::b59ae8e812e3cf243aad21ec12cf3ef6
https://doi.org/10.1109/cpem.2016.7540518
https://doi.org/10.1109/cpem.2016.7540518
Publikováno v:
2016 Conference on Precision Electromagnetic Measurements (CPEM 2016).
We report measurements of the magneto-capacitance and the associated dissipation factor of graphene-based quantum Hall effect devices at frequencies in the kHz range. The main motivation for this work is yielding information for the modeling and opti
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::41121a5925155d122d05262017fe14ab
https://doi.org/10.1109/cpem.2016.7540651
https://doi.org/10.1109/cpem.2016.7540651
Autor:
A. Müller, J. Feilhauer, C.-C. Kalmbach, Rolf J. Haug, Klaus Pierz, Jürgen Schurr, Frank Hohls, F. J. Ahlers, Mattias Kruskopf
Publikováno v:
Physical Review B 94 (2016), Nr. 20
We investigate the 1/f noise properties of epitaxial graphene devices at low temperatures as a function of temperature, current, and magnetic flux density. At low currents, an exponential decay of the 1/f noise power spectral density with increasing
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::2c895277fc9e1019438f303f224b9e27
Publikováno v:
IEEE Transactions on Instrumentation and Measurement. 60:2512-2516
We realize and experimentally study magnetic field reversible serial quantum Hall arrays. Our devices consist of two Hall bars with rectangular or square geometry connected in series. We show that for such serial Hall arrays, the correct quantum Hall
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::82461d4a2c744d6fb55e5cc7834f78e7
https://doi.org/10.1109/tim.2010.2099390
https://doi.org/10.1109/tim.2010.2099390
Publikováno v:
IEEE Transactions on Instrumentation and Measurement. 60:2455-2461
We study the magnetotransport properties and Hall resistance quantization in a set of AlGaAs/GaAs heterostructures grown in a high-mobility molecular beam epitaxy system. The data show that, with reduced spacer layer width, the electron mobility in s
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::688b5fe181fb4db34a4406a6fd469060
https://doi.org/10.1109/tim.2010.2100651
https://doi.org/10.1109/tim.2010.2100651