Browsing by Author "Courtois, H."

Now showing 1 - 5 of 5
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    Nonlinear thermovoltage in a single-electron transistor
    (American Physical Society, 2019-04-02) Peltonen, J. T.; Erdman, P. A.; Bhandari, B.; Dutta, B.; Courtois, H.; Fazio, R.; Taddei, F.; Pekola, J. P.; Department of Applied Physics; Quantum Phenomena and Devices; Centre of Excellence in Quantum Technology, QTF; National Enterprise for nanoScience and nanoTechnology; National Research Council of Italy; Université Grenoble Alpes; CNR-ENEA-EURATOM Association
    We perform direct thermovoltage measurements in a single-electron transistor, using on-chip local thermometers, in both the linear and nonlinear regimes. Using a model which accounts for cotunneling, we find excellent agreement with the experimental data with no free parameters even when the temperature difference is larger than the average temperature (far-from-linear regime). This allows us to confirm the sensitivity of the thermovoltage on cotunneling and to find that in the nonlinear regime the temperature of the metallic island is a crucial parameter. Surprisingly, the metallic island tends to overheat even at zero net charge current, resulting in a reduction of the thermovoltage.
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    Origin of Hysteresis in a Proximity Josephson Junction
    (American Physical Society (APS), 2008) Courtois, H.; Meschke, M.; Peltonen, J. T.; Pekola, Jukka P.; Department of Applied Physics; Teknillisen fysiikan laitos; Perustieteiden korkeakoulu; School of Science
    We investigate hysteresis in the transport properties of superconductor–normal-metal–superconductor (S-N-S) junctions at low temperatures by measuring directly the electron temperature in the normal metal. Our results demonstrate unambiguously that the hysteresis results from an increase of the normal-metal electron temperature once the junction switches to the resistive state. In our geometry, the electron temperature increase is governed by the thermal resistance of the superconducting electrodes of the junction.
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    Single Quantum Level Electron Turnstile
    (2016-04-20) Van Zanten, D. M T; Basko, D. M.; Khaymovich, I. M.; Pekola, J. P.; Courtois, H.; Winkelmann, C. B.; Université Grenoble Alpes; CNRS; Department of Applied Physics
    We report on the realization of a single-electron source, where current is transported through a single-level quantum dot (Q) tunnel coupled to two superconducting leads (S). When driven with an ac gate voltage, the experiment demonstrates electron turnstile operation. Compared to the more conventional superconductor-normal-metal-superconductor turnstile, our superconductor-quantum-dot-superconductor device presents a number of novel properties, including higher immunity to the unavoidable presence of nonequilibrium quasiparticles in superconducting leads. Moreover, we demonstrate its ability to deliver electrons with a very narrow energy distribution.
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    Trapping hot quasi-particles in a high-power superconducting electronic cooler
    (IOP Publishing, 2013) Nguyen, H. Q.; Aref, T.; Kauppila, V. J.; Meschke, M.; Winkelmann, C. B.; Courtois, H.; Pekola, Jukka P.; Department of Applied Physics; Teknillisen fysiikan laitos; Perustieteiden korkeakoulu; School of Science
    The performance of hybrid superconducting electronic coolers is usually limited by the accumulation of hot quasi-particles in their superconducting leads. This issue is all the more stringent in large-scale and high-power devices, as required by the applications. Introducing a metallic drain connected to the superconducting electrodes via a fine-tuned tunnel barrier, we efficiently remove quasi-particles and obtain electronic cooling from 300 mK down to 130 mK with a 400 pW cooling power. A simple thermal model accounts for the experimental observations.
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    Trapping hot quasi-particles in a high-power superconducting electronic cooler
    (2013-08-13) Nguyen, H.Q.; Aref, T.; Kauppila, V.J.; Meschke, M.; Winkelmann, C.B.; Courtois, H.; Pekola, J.P.; Department of Applied Physics
    The performance of hybrid superconducting electronic coolers is usually limited by the accumulation of hot quasi-particles in their superconducting leads. This issue is all the more stringent in large-scale and high-power devices, as required by the applications. Introducing a metallic drain connected to the superconducting electrodes via a fine-tuned tunnel barrier, we efficiently remove quasi-particles and obtain electronic cooling from 300 mK down to 130 mK with a 400 pW cooling power. A simple thermal model accounts for the experimental observations.