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A short historical review of the development of tunneling concept in low-temperature condensed matter physics, physical electronics, nuclear physics, chemistry, and biology is given. It is shown how the preceding classical physics is related to the quantum mechanical tunneling phenomenon. The emphasis is placed on the common features of various tunneling manifestations in nature. The triumph of the Faraday–Maxwell–Einstein idea of the physical field has been demonstrated. [ABSTRACT FROM AUTHOR]

The physico-mathematical model applied to ground tests for geomagnetic plasma exposure based on the combined consideration of surface and bulk processes of transport and charge accumulation for calculating the kinetics of charging high-resistance dielectrics irradiated by medium-energy monoenergetic electrons (from 6 to 30 keV) is proposed. The model takes into account the contribution to the charging of the dielectric by the trains of longitudinal optical phonons generated by each thermalizing primary electron with energy below the band gap of the dielectric, which supplements the induced conduction current due to the generation of electron-hole pairs. As a result, the current induced by trains of longitudinal optical phonons of the tunnel conductivity through free electron traps is introdused, as well as the current induced in the conduction band due to multiphonon ionization the electron traps by trains of longutudinal optical phonons in the region of existence of electric field. Using the example of the α-Al2O3 (sapphire) dielectric, the results of computer simulation of the internal currents distributions, charges, and electric field in the dielectric with the open surface irradiated by monoenergetic electrons with energies from 6 to 30 keV are presented according with the achievement the quasi-equilibrium in the irradiated part of the dielectric and with switching of the energy of primary electrons during the irradiation process. [ABSTRACT FROM AUTHOR]

In this paper, the electrical properties of the Fe/MgO/Fe tunnel system are studied using an original technique, in which upper metal element was an iron probe inserted into the dielectric in a controlled manner. This makes it possible to study the electrical properties of the Fe/MgO/Fe system upon changing the physical parameters such as contact area and dielectric thickness. Based on the obtained results of the conductivity measurements, the corresponding approximation coefficients are determined. This allows to analytically calculating the I-V characteristics in a wide range of dielectric thickness and contacting area. It is established that the resistance of the Fe/MgO/Fe system is non-monotonically dependent on the dielectric thickness and growth in ∼ 3 times when the MgO thickness increases by 0.21 nm. An increase of the contact area leads to a linear decrease of the resistance of the Fe/MgO/Fe system while preserving the value of current density and approaching the experimental I-V characteristic to a linear dependence. This effect is attributed to the influence of local areas of conductivity, arising due to the defects and impurities, on the specifics of the conductivity of the whole system. The thickness of the dielectric and the limit voltage, at which the tunnel type of conductivity is preserved, are determined from I-V characteristics during the process of electrical breakdown of the dielectric. It was established that the dielectric strength increases to 6.6 MV/cm for the MgO thicknesses ranging from 1 nm to 4 nm and decreases to 6.2 MV/cm in the range from 4 nm to 10 nm. [ABSTRACT FROM AUTHOR]

Tunnel field effect transistor (TFET) is a potential candidate to replace CMOS in deep‐submicron region due to its lower SS (subthreshold swing, <60 mV/decade) at room temperature. However, the conventional TFET suffers from low tunneling current and high ambipolar current. To overcome these two shortcomings, a new structure, known as Hetero‐dielectric gate TFET (HDG TFET), has been proposed in the literature. To analyze the electrical characteristics of this structure, a closed form of analytical expression of current is required. This paper presents the analytical current model for Hetero‐dielectric single gate (HDSG) TFET structure without using any iterative method. The developed analytical models show a good agreement with 2‐D TCAD simulator results. The model is used to study the electrical behavior of the proposed device under various physical and bias variations. [ABSTRACT FROM AUTHOR]

The results of theoretical modeling of the dynamics of a charged large molecule in an aqueous solution under the influence of gravity, vertical electric field, and drag force are presented. Computations were carried out for the DNA molecule. It is shown that one can smoothly control the speed of movement of a molecule by an electric field so that it is possible to carry out accurate sequencing by the tunneling current method. It was also shown that the speed of movement of a molecule can be reduced to some decimal cm/s, which is equivalent to sequencing 105–106 nucleoids per second. [ABSTRACT FROM AUTHOR]

The electrical transport mechanism of non-percolated copper ultrathin films was studied. For this purpose, resistance behavior was measured during sample growth, aging in vacuum and oxidation in air, and contrasted with a model based on tunnel current and on film’s morphology. In addition, the electrical characterization of chromium and gold ultrathin films was performed and compared with that obtained for copper. All films were grown on muscovite mica through thermal evaporation under high vacuum conditions. Electrical characterization throughout films’ growth, aging and oxidation was performed in situ and in real time. Finally, to address the transport mechanism of non-percolated oxidized copper films, samples were put into a cryostat in which electrical resistance was measured changing the temperature between 35 and 300 K. It was found that the three materials present an almost constant resistance decay during growth. This resistance decrease was studied for copper films by fitting a tunnel transport model which considered islands’ distance as a function of film thickness, indicating a resistance reduction given by coalescing islands. During aging, the resistance of copper and gold ultrathin films increases without reaching a saturation value after 30 min, with a behavior independent of the material or the initial resistance. The theoretical model applied to copper film resistance explains the increment by further formation of 3D structures, mainly conducted by atom diffusion on the substrate. Finally, a change in the resistance behavior is observed during the oxidation of copper ultrathin films, electrical transport is mediated by two mechanisms a semi-conductor type, resembling that of oxidized chromium layers, and a tunnel conduction type, observed in gold films. The first mechanism dominates when temperature is above 200 K, while tunneling is the main process for temperatures below 150 K.

In this study, channel potential for silicon‐based doped dual‐metal double‐gate tunnel field‐effect transistor structure is analytically solved using the evanescent‐mode approach in the sub‐threshold region. This method generally describes short channel effects in the entire channel region of the device structure and predicts different characteristic length λ which depends on tunnel current and does not depend along a transverse direction within the channel. The model is valid for the whole device structure rather than just semiconductor/insulator interfaces. The impact of variation of bias condition on channel potential is also investigated in the sub‐threshold region. Finally, drain current is evaluated using Kane's and Kleysh's model and validated with a calibrated simulation, which has been carried out using 2D TCAD Sentaurus simulator. [ABSTRACT FROM AUTHOR]

Ferroelectric tunnel junction (FTJ) is a promising low power nonvolatile memory for beyond-CMOS applications. In this paper, Co/BaTiO3/SrRuO3 FTJs are fabricated, simulated, and their electrical characteristics are measured by capacitance–voltage (${C}$ – ${V}$), current–voltage (${I}$ – ${V}$), and high-frequency S-parameter measurements. Ferroelectricity of the ultrathin BaTiO3 (~3.2 nm) film is first verified by a butterfly shaped hysteresis ${C}$ – ${V}$ profile, from which saturation polarizations are calculated in the ON state and OFF state as ${P}_{ \mathrm{ON}}=+ {20}\,\,\mu {C} / {\text{cm}}^{ {2}}$ and ${P}_{ \mathrm{OFF}}=- {25}\,\,\mu {C}/{\text{cm}}^{ {2}}$ , respectively. The numerical simulation of the FTJ device is performed using experimental electronic band parameters of the heterostructure. The device structure was optimized for ON/OFF ratio, ${I}_{ \mathrm{ON}} / {I}_{ \mathrm{OFF}}= {75}$ for a depolarization field, ${E}_{{dpol}} < { {10}}^{ {6}}~{V} / {\text{cm}}$. The calculated tunnel currents of $ {250}\,\,{nm}\times {250}\,\,{nm}$ FTJ in ON state (${I}_{ \mathrm{ON}}= {250}\times {250}^{- {250}}\,\,{A}$) and OFF state (${I}_{{OFF}}={{1.75}\times {250}}^{{-9}}\,\,{A}$) match with experimental values. From the S-parameters of RF measurements, the high-frequency small-signal device model of the FTJ in ON state (${C}_{ \mathrm{ON}}= {250}\,\,{fF},{R}_{ \mathrm{ON}}={0.8}\,\,{M}\Omega$) and OFF state (${C}_{ \mathrm{OFF}}={ {250}}\,\,{fF},{R}_{ \mathrm{OFF}}= {250}\,\,{M}\Omega$) is developed for a frequency range from 50 MHz to 5 GHz. The extracted capacitor model of Co/BaTiO3/SrRuO3 FTJ is useful for high-frequency simulation of benchmark FTJ circuits. [ABSTRACT FROM AUTHOR]

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The paper focuses on the effect of a multilevel impurity in a graphene nanoribbon on the tunnel current flowing in the contact of the latter with metal. Calculations of the ballistic current in a graphene nanoribbon and the tunnel current of the ribbon contact with metal are performed. Analysis is provided for the dependence of current-voltage characteristic of the contact on the integral of transition between impurity levels of the nanoribbon. [ABSTRACT FROM AUTHOR]