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TT: Fachverband Tiefe Temperaturen
TT 49: Superconductivity: Superconducting Electronics I
TT 49.8: Talk
Wednesday, March 14, 2018, 11:45–12:00, H 2053
Ultrasensitive Microwave Detector — •Mikko Möttönen1, Joonas Govenius1, Roope Kokkoniemi1, Visa Vesterinen1,2, Dibyendu Hazra1, Marton Gunyho1, Russell E. Lake1,3, and Kuan Yen Tan1,4 — 1QCD Labs, Department of Applied Physics, Aalto University, Aalto, Finland — 2VTT Technical Research Centre of Finland Ltd, VTT, Finland — 3NIST, Boulder, Colorado, USA — 4CQC2T, University of New South Wales, Australia
Intense development of nanobolometers has taken place for well more than a decade with the aim to reach NEP = 1e-20 W/rtHz which is required, for example, in effcient measurements of the cosmic terahertz spectrum in space. Furthermore, observation of single photons at increasingly long wavelengths is a long-standing effort [1]. We present a microwave nanobolometer based on proximity Josephson junctions. Using positive electrothermal feedback, we show that we can achieve a single-shot detection fidelity of 0.56 for 1.1-zJ pulses of 8.4-GHz photons [2]. This is more than an order of magnitude improvement over the previous thermal detectors. Importantly, we also observe that we can reach a sensitivity of NEP = 2e-20 W/rtHz with our detector in the linear continuous mode. This was achieved using a Josephson parametric amplifier in the detector readout chain [3]. In the future, ultrasensitive bolometers and thermometers are expected to play an important role in quantum information processing and quantum thermodynamics.
K. Inomata et al., Nat. Commun. 7, 12303 (2016).
J. Govenius et al., Phys. Rev. Lett. 117, 030802 (2016).
V. Vesterinen et al. , Supercond. Sci. Technol. 30, 085001 (2017).