Single Electronics

Abstract

With the advances of fabrication techniques in recent years‚ it has become possible to fabricate tunnel junctions of increasingly small dimensions. This opens the realm of mesoscopic physics which enables the study of a wide range of novel phenomena. It involves samples that combine both the characteristics of macroscopic world (i.e.‚ classical effects) and those of microscopic world (i.e.‚ quantum effects). The characteristic length scale of mesoscopic samples varies from nanometers to tens of micrometers.In mesoscopic devices‚ one of the surprising results is that the electron wave interference effects produce quantum conductance fluctuation and weak localization. [1][2][3] In addition‚ it has also been shown to give rise to the Aharonov-Bohm effect in ring geometries. 4 In contrast‚ the ballistic transport of electrons through short and narrow channels results in conductances that have quantized values (see Chapter 10). 5 The discreteness of the electron energy spectrum has been probed in semiconductor heterostructures 6‚7 and small metal particles. 7‚8Here‚ we will focus on the study of systems in which the discrete nature of the electronic charge is important. This discreteness is usually not evident in conventional electronic devices‚ in which the current is regarded as a continuous charge flow. However‚ if electrons are confined to small isolated regions (islands) that are weakly coupled to the external circuit‚ the discreteness of the electronic charge can greatly influence the electrical transport properties of the system. The capacitance of the island to the external circuit can be so small that the charging energy required to add a single electron becomes the dominant energy. This phenomenon is called the "single electron charging effects".

Molecular switching operation in gate constricted interface of MoS2 and hBN heterostructure

“…The energy diagrams corresponding to the specific (hypothetical) case are drawn where the barrier height is shown without the applied bias and with the applied bias at the left contact and at −2 V of V local across the channel and no voltage drop at the right contact as shown in Figure 5(a) and 5(b). Enough bias is applied for a transition from a trapezoidal barrier to a triangular barrier as in Figure 5(b) and the position of the Fermi level can be tuned using the fixed V SD 53,54 as well as by molecular interaction at a fixed V SD . Further, the first-principle calculations were performed using DFT in NO 2 adsorbed monolayer MoS 2 .…”