The Quantum Capacitance Detector: A concept for a pair-breaking radiation detector based on the single Cooper-pair box

TL;DR

This paper proposes a superconducting pair-breaking detector using a single Cooper-pair box for far-infrared and sub-millimeter radiation, aiming to achieve high sensitivity comparable to existing advanced detectors.

Contribution

It introduces a novel detector design based on a Cooper-pair box that can be multiplexed and potentially rivals current state-of-the-art sensors.

Findings

Theoretical sensitivity limits are modeled and discussed.

Predicted sensitivities are comparable to transition-edge sensors.

The design is suitable for large array implementation in astronomy.

Abstract

We present a proposed design for a pair-breaking photodetector for far-infrared and sub-millimeter radiation. Antenna-coupled radiation generates quasiparticles in a superconducting absorber, the density of which are measured using a single Cooper-pair box. Readout is performed using an electromagnetic oscillator or a microwave resonator, which is well suited for frequency multiplexing in large arrays. Theoretical limits to detector sensitivity are discussed and modeled, with predicted sensitivities rivaling transition-edge sensors and microwave kinetic inductance detectors. We anticipate that this detector can be used to address key scientific goals in far-infrared and sub-millimeter astronomy.