Fast and Ultrasensitive Electrometer Operating at the Single-Photon Level
Fast and Ultrasensitive Electrometer Operating at the Single-Photon Level
Fast, ultrasensitive electrometers have been instrumental to the advancement of basic science. However, many applications (such as readout of quantum-dot-based qubits, and mediation of optomechanical interactions) could benefit from operating such charge sensors at low power. Here the authors demonstrate a charge sensitivity of 14 $\ensuremath{\mu}\phantom{\rule{0}{0ex}}e/\sqrt{\mathrm{Hz}}$ with a cavity-embedded Cooper-pair …