Singleelectron tunneling with slow insulators
Abstract
The usual paradigm in the theory of electron transport is related to the fact that the dielectric permittivity of the insulator is assumed to be constant, with no time dispersion. We take into account the "slow" polarization dynamics of the dielectric layers in the tunnel barriers in the fluctuating electric fields induced by singleelectron tunneling events and study transport in the singleelectron transistor (SET). Here "slow" dielectric implies a time scale that is slow compared to the characteristic time scales of the SET chargingdischarging effects. We show that for strong enough polarizability, such that the induced charge on the island is comparable to the elementary charge, the transport properties of the SET substantially deviate from the known results of transport theory of the SET. In particular, the Coulomb blockade is more pronounced at finite temperature, the conductance peaks change their shape, and the currentvoltage characteristics show the memory effect (hysteresis). However, in contrast to SETs with ferroelectric tunnel junctions, here the periodicity of the conductance in the gate voltage is not broken; instead, the period strongly depends on the polarizability of the gate dielectric. We uncover the fine structure of the hysteresis effect where the "large" hysteresis loop may include a number of "smaller" loops. Also we predict the memory effect in the currentvoltage characteristics I (V ) , with I (V )≠I (V ) .
 Publication:

Physical Review B
 Pub Date:
 September 2015
 DOI:
 10.1103/PhysRevB.92.115425
 arXiv:
 arXiv:1501.00261
 Bibcode:
 2015PhRvB..92k5425F
 Keywords:

 77.80.e;
 72.80.Tm;
 77.84.Lf;
 Ferroelectricity and antiferroelectricity;
 Composite materials;
 Condensed Matter  Strongly Correlated Electrons;
 Condensed Matter  Mesoscale and Nanoscale Physics
 EPrint:
 13 pages and 11 figures