Ultrasensitive Microwave Bolometer

22 Jul 2019, 11:55
15m
Auditorium G. Testori (Milano)

Auditorium G. Testori

Milano

Piazza Città di Lombardia, 1, 20124 Milano MI
Invited Presentation Low Temperature Detector Development and Physics Orals LM 001

Speaker

Dr Mikko Möttönen (Aalto University)

Description

Intense development of nanobolometers has taken place for well more than a decade with the aim to reach noise equivalent power NEP = 10e-20 W/rtHz. Furthermore, observation of single photons at increasingly long wavelengths is a long-standing effort. We present a microwave nanobolometer based on superconductor/normal-metal/superconductor 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 [1]. This is more than an order of magnitude improvement over the previous thermal detectors. Furthermore, we observe that we can reach NEP = 2*10e-20 W/rtHz with our detector in the linear bolometric mode [2]. The measured frequency dependence of the NEP suggest that this bolometer is capable of detecting single 0.3-zJ photons. These results were achieved by integrating the bolometer with a quantum-limited Josephson parameteric apmli?er and further improvements are expected for example using two-dimensional materials.

[1] J. Govenius, R. E. Lake, K. Y. Tan, and M. Möttönen, Phys. Rev. Lett. 117, 030802 (2016).

[2] R. Kokkoniemi et al., arXiv:1806.09397 (2018).

Less than 5 years of experience since completion of Ph.D N
Student (Ph.D., M.Sc. or B.Sc.) N

Primary author

Dr Mikko Möttönen (Aalto University)

Presentation Materials