LOW-TEMPERATURE CONDUCTANCE OF NANOSYSTEMS UNDER CONDITIONS OF WEAK COUPLING WITH A MICROWAVE GENERATOR
A. S. Jaroshevich1, V. A. Tkachenko1,2, Z. D. Kvon1,2, N. S. Kuzmin2, O. A. Tkachenko1, D. G. Baksheev2, I. V. Marchishin1, A. K. Bakarov1, E.E. Rodyakina1,2, V. A. Antonov1, V. P. Popov1, A. V. Latyshev1,3
1Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
2Novosibirsk State University, Novosibirsk, Russia
3Novosibirsk State University
Keywords: Field effect transistor, silicon-on-insulator, two-dimensional electron gas, short constriction, GaAs/AlGaAs heterostructures, mesoscopic transport, microwave photoconductance, dynamic chemical potential, coaxial cables, edge capacitance
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, as well as 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 regime of the devices; outside this regime, the sign of the microwave photoconductance depends on the mesoscopic state of the sample and the gate voltage interval under study. The mechanism 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 found to be forced in-phase charge oscillations in contacts to the semiconductor due to capacitive connections in the near metallic environment of the sample.
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