Abstract
The high-frequency radiation emitted by a quantum conductor presents a rising interest in quantum physics and condensed matter. However, its detection with microwave circuits is challenging. Here, we propose to use the photon-assisted shot noise for on-chip radiation detection. It is based on the low-frequency current noise generated by the partitioning of photon-excited electrons and holes, which are scattered inside the conductor. For a given electromagnetic coupling to the radiation, the photon-assisted shot noise response is shown to be independent on the nature and geometry of the quantum conductor used for the detection, up to a Fano factor, characterizing the type of scattering mechanism. Ordered in temperature or frequency range, from few tens of mK or GHz to several hundred of K or THz respectively, a wide variety of conductors can be used like Quantum Point Contacts (this work), diffusive metallic or semi-conducting films, graphene, carbon nanotubes and even molecule, opening new experimental opportunities in quantum physics.
Highlights
The high-frequency radiation emitted by a quantum conductor presents a rising interest in quantum physics and condensed matter
We propose an on-chip radiation detection based on photo-assisted shot noise (PASN)
This simple link is better understood if we remark that PASN is the quantum manifestation of the rectification property of ordinary shot noise[17–20], which is proportional to the absolute value of the drain-source voltage
Summary
It consists of two separate excitation and measurement circuit lines etched in a high-mobility 2DEG. In series with the right QPC, tuned on a resistance plateau RDS , it experiences the emitter line voltage fluctuations via the coupling capacitance CC up to the cutoff frequency fmax The number of electron-hole pairs generated in the detector line is a direct funcÀtion of the rÁadiated noise power integrated up to frequency min eVdEs=h; fmax (Supplementary Discussion 1 and Supplementary Fig. 2). Their scattering by the QPC detector generates a low-frequency PASN, which is measured. Their scattering by the QPC detector generates a low-frequency PASN, which is measured. fmax depends on all QPC resistances and on the self-capacitance Cself of the 2DEG part between the QPCs in series
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
