Detection of On-Chip Generated Weak Microwave Radiation Using Superconducting Normal-Metal SET

Behdad Jalali-Jafari,Alexander Zorin,Sergey Lotkhov

doi:10.3390/app6020035

Behdad Jalali-Jafari, Alexander Zorin + Show 1 more

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https://doi.org/10.3390/app6020035

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Abstract

The present work addresses quantum interaction phenomena of microwave radiation with a single-electron tunneling system. For this study, an integrated circuit is implemented, combining on the same chip a Josephson junction (Al/AlO x /Al) oscillator and a single-electron transistor (SET) with the superconducting island (Al) and normal-conducting leads (AuPd). The transistor is demonstrated to operate as a very sensitive photon detector, sensing down to a few tens of photons per second in the microwave frequency range around f ∼ 100 GHz. On the other hand, the Josephson oscillator, realized as a two-junction SQUID and coupled to the detector via a coplanar transmission line (Al), is shown to provide a tunable source of microwave radiation: controllable variations in power or in frequency were accompanied by significant changes in the detector output, when applying magnetic flux or adjusting the voltage across the SQUID, respectively. It was also shown that the effect of substrate-mediated phonons, generated by our microwave source, on the detector output was negligibly small.

Highlights

Over the past few decades, rapid progress in nanofabrication has brought up a scope of very sensitive mesoscopic superconducting circuits operating with single quanta of physical quantities.These advances are promising for applications in electrical metrology and quantum information technology, for example, in single-electron pumping [1,2,3], which is the basic mechanism for the electron-counting capacitance standard [4,5] and a quantum current standard [6]
We report on the radiation detection peculiarities of an NISIN detector included in a complete microwave circuit with a Josephson-junction-based microwave generator coupled to the detector via the specially designed transmission line
We fabricated and studied at 15 mK a microwave circuit combining on the same chip a Josephson junction microwave source and an single-electron transistor (SET)-based photon detector with a superconducting island as a sensitive element

Summary

Introduction

Over the past few decades, rapid progress in nanofabrication has brought up a scope of very sensitive mesoscopic superconducting circuits operating with single quanta of physical quantities. These advances are promising for applications in electrical metrology and quantum information technology, for example, in single-electron pumping [1,2,3], which is the basic mechanism for the electron-counting capacitance standard [4,5] and a quantum current standard [6]. The single-quantum circuits must be protected from stray electromagnetic radiation (emitted, for example, by warmer parts of the cryogenic setup) down to the utmost level of single microwave photons. The radiation-induced generation of quasiparticles is considered to be an important decoherence mechanism in the superconducting qubit systems

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