Bolometric detection of quantum shot noise in coupled mesoscopic systems

We demonstrate a scheme to detect the quantum shot noise in coupled mesoscopic systems. By applying the noise thermometry to the capacitively coupled quantum point contacts (QPCs) we prove that the noise temperature of one QPC is in perfect proportion to that of the other QPC which is driven to nonequilibrium to generate quantum shot noise. The present mesoscopic bolometry, which is sensitive to the energy flow of ~1 fW, allows us to detect the energy exchange between quantum systems at finite frequency and can also be applied for diverse precise measurements.