Abstract
A strong response of nanosystems to the action of weak microwave power through the gap between the sample and the end of the coaxial cable from the microwave generator is detected by measurements at 4.2 K of the conductance of a short-channel \(p\) -type silicon transistor and samples with a short quantum point contact in a two-dimensional electron gas of GaAs/AlGaAs heterostructures. The conductance response is gigantic in the tunnel mode of the devices, and the sign of the microwave photoconductance outside this mode depended on the mesoscopic state of the sample and the studied range of gate voltage. The nature of the discovered effects is elucidated by modeling mesoscopic transport within the framework of single-particle quantum mechanics and the Landauer formula as well as by analyzing the basic circuits of electrical control of the semiconductor device. The main reason for the response of nanosystems to microwave exposure is forced in-phase charge oscillations in contacts to the semiconductor due to capacitive coupling in the near metallic environment of the sample.
