We have fabricated microwave nanobolometers using normal-metal nanowires. A part of the wire acts as an absorber of the microwave radiation whereas the remaining parts act as a sensitive thermometer with proximity-induced superconductivity. We use electrothermal feedback enhance the coupling of the temperature to the electrical degrees of freedom in the bolometer allowing us to measure a change in the radio-frequency signal caused by the absorption of microwave radiation. At the regime of large positive feedback, two metastable electron temperature states arise enabling threshold detection of microwave pulses down to 200 8.4-GHz photons, i.e., 1 zeptojule of energy. The measured noise-equivalent power of our nanobolometer is 2*10-20 W/Hz1/2 at 1-ms timeconstant. Finally, I present results on the devices where the normal-metal is replaced by graphene for enhanced performance.
*We acknowledge financial support by European Research Council under Grant No. 681311 (QUESS) and by the Academy of Finland
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Presenters
Dibyendu Hazra
QCD Labs, Department of Applied Physics, Aalto University
Authors
Dibyendu Hazra
QCD Labs, Department of Applied Physics, Aalto University
Joonas Govenius
QCD Labs, Department of Applied Physics, Aalto University
Russell Lake
National Institute of Standards and Technology
NIST - Boulder
NIST
QCD Labs, Department of Applied Physics, Aalto University
Roope Kokkoniemi
Department of applied physics, Aalto University
QCD Labs, Department of Applied Physics, Aalto University
Visa Vesterinen
VTT Technical Research Centre of Finland Ltd
Marton Gunyho
QCD Labs, Aalto University
QCD Labs, Department of Applied Physics, Aalto University
Kuan Tan
QCD Labs, Department of Applied Physics, Aalto University
Department of applied physics, Aalto University
Jan Goetz
Walther-Meißner-Institut & TU München
QCD Labs, Aalto University
QCD Labs, Department of Applied Physics, Aalto University
Matti Partanen
QCD Labs, Department of Applied Physics, Aalto University
QCD Labs, Aalto University
Slavomir Simbierowicz
VTT Technical Research Centre of Finland Ltd
Leif Grönberg
VTT Technical Research Centre of Finland Ltd
antti Laitinen
Low Temperature Laboratory, Department of Applied Physics, Aalto University
Pertti Hakonen
Low Temperature Laboratory, Department of Applied Physics, Aalto University
Juha Hassel
VTT Technical Research Centre of Finland Ltd
olli Pentti Saira
Low Temperature Laboratory, Department of Applied Physics, Aalto University
Jukka Pekola
School of Science, Aalto University
Aalto University
Low Temperature Laboratory, Department of Applied Physics, Aalto University
Janne Lehtinen
VTT Technical Research Centre of Finland Ltd
Mika Prunnila
VTT Technical Research Centre of Finland Ltd
Mikko Möttönen
QCD Labs, Department of Applied Physics, Aalto University