Efros–Shklovskii hopping in the electronic transport in 2D p-GaAs

We have investigated the resistivity of a 2D hole system in GaAs in the temperature range 200 mK < T < 800 mK at zero magnetic field and low hole densities when the system is near the metal–insulator transition in the insulating side. We have found that the resistivity follows the Efros–Shklovskii variable range hopping (ES-VRH) law, this behaviour is consistent with the existence of a Coulomb gap. The resistivity scales with temperature and the prefactor has been found independent of temperature and density, thus confirming the dominance of hole–hole interaction.

Одноэлектронный транспорт в коллоидных квантовых точках узкозонных полупроводников

Single-electron transport in the planar structure of colloidal quantum dots of InSb, PbS, CdSe semiconductors was studied using a scanning tunneling microscope. On the current – ​​voltage characteristics, sections of the current dip were observed similar to the Coulomb gap. Qualitative and numerical comparative estimates suggest that one-electron transport and a phenomenon similar to the Coulomb blockade are observed in the structure of the set of quantum dots. When measuring the current-voltage characteristics, the white-light illumination of the sample breaks the Coulomb blockade, and it can be expected that an instrument element based on such a structure will respond to individual photons. In the region of the Coulomb gap, current oscillations with frequencies in the terahertz range are possible.

Квантовая динамика заряда в квазиодномерных сверхпроводниках

—Volt-ampere characteristics of narrow superconducting titanum wires have been studied experimentally. The narrowest specimens measured by means of high-resistance contacts have revealed a behavior nontrivial for superconductors: the Coulomb blockade. The Coulomb gap size correlates with the frequency of quantum phase slips. The observation confirms the identity of quantum dynamics of charge in the Josephson junctions and in the quasi-one-dimensional superconducting channels in the regime of quantum fluctuations of the order parameter.