Direct current hopping conductance along DNA chain

This paper proposes a model of direct current (DC) electron hopping transport in DNA, in which DNA is considered as a binary one-dimensional disordered system. To quantitatively study the DC conductivity in DNA, it numerically calculates the DC conductivity of DNA chains with different parameter values. The result shows that the DC conductivity of DNA chain increases with the increase of temperature. And the conductivity of DNA chain is depended on the probability p, which represents the degree of compositional disorder in a DNA sequence to some extent. For p<0.5, the conductivity of DNA chain decreases with the increase of p, while for p\geq0.5, the conductivity increases with the increase of p. The DC conductivity in DNA chain also varies with the change of the electric field, it presents non-Ohm's law conductivity characteristics.     

Probing the spin state of a single electron trap by random telegraph signal

We have studied the random telegraph signal (RTS) generated by a single paramagnetic spin center adjacent to a submicrometer silicon metal-oxide-semiconductor field-effect transistor. An in-plane magnetic field induces a substantial change in the statistics of the RTS. We show that a model using the grand partition theorem can qualitatively explain the change in statistics of the RTS as a function of the applied magnetic field. While the data at high temperatures can be well described by this simple model, quantitative discrepancy increases as the temperature is lowered.     

A random telegraph signal of Mittag-Leffler type

A general method is presented to explicitly compute autocovariance functions for non-Poisson dichotomous noise based on renewal theory. The method is specialized to a random telegraph signal of Mittag-Leffler type. Analytical predictions are compared to Monte Carlo simulations. Non-Poisson dichotomous noise is non-stationary and standard spectral methods fail to describe it properly as they assume stationarity.     

Microwave irradiation effects on random telegraph signal in a MOSFET

We report on the change of the characteristic times of the random telegraph signal (RTS) in a MOSFET operated under microwave irradiation up to 40 GHz as the microwave field power is raised. The effect is explained by considering the time dependency of the transition probabilities due to a harmonic voltage generated by the microwave field that couples with the wires connecting the MOSFET. The RTS experimental data are in agreement with the prediction obtained with our model.     

Shot-noise-induced random telegraph noise in shuttle current

Random telegraph noise in the electric current produced by shot noise is predicted for an array of movable colloid particles by Monte Carlo and molecular dynamics calculations. The electron transport is attributed to the shuttle mechanism where moving colloid particles carry charges. The colloid-particle motion induced by the source-drain voltage shows periodic and/or quasiperiodic vibrations, and the current value depends on the vibration modes. Shot noise that is uncorrelated with the colloid-particle motion causes transitions between the periodic and quasiperiodic vibration modes, resulting in random switching between the current levels corresponding to the vibration modes.     

Modeling random telegraph signal noise in CMOS image sensor under low light based on binomial distribution

The random telegraph signal noise in the pixel source follower MOSFET is the principle component of the noise in the CMOS image sensor under low light. In this paper, the physical and statistical model of the random telegraph signal noise in the pixel source follower based on the binomial distribution is set up. The number of electrons captured or released by the oxide traps in the unit time is described as the random variables which obey the binomial distribution. As a result,the output states and the corresponding probabilities of the first and the second samples of the correlated double sampling circuit are acquired. The standard deviation of the output states after the correlated double sampling circuit can be obtained accordingly. In the simulation section, one hundred thousand samples of the source follower MOSFET have been simulated,and the simulation results show that the proposed model has the similar statistical characteristics with the existing models under the effect of the channel length and the density of the oxide trap. Moreover, the noise histogram of the proposed model has been evaluated at different environmental temperatures.     

Influence of a random telegraph process on the transport through a point contact

We describe the transport properties of a point contact under the influence of a classical two-level fluctuator. We employ a transfer matrix formalism allowing us to calculate arbitrary correlation functions of the stochastic process by mapping them on matrix products. The result is used to obtain the generating function of the full counting statistics of a classical point contact subject to a classical fluctuator, including extensions to a pair of two-level fluctuators as well as to a quantum point contact. We show that the noise in the quantum point contact is a sum of the (quantum) partitioning noise and the (classical) noise due to the two-level fluctuator. As a side result, we obtain the full counting statistics of a quantum point contact with time-dependent transmission probabilities.     

Influence of the substrate voltage on the random telegraph signal parameters in submicron n-channel metal-oxide-semiconductor field-effect transistors under a constant inversion charge density

In this paper, the impact of the substrate bias U_BS on the parameters of a repulsive random telegraph signal in an n-channel metal-oxide-semiconductor field-effect transistor is studied. Particular attention is paid to the variation of the capture time constant F_c with the channel current I in linear operation. It is shown that the strong reduction of F_c with I can be explained by the Coulomb blockade effect. The corresponding Coulomb energy (E of the charged-near-interface oxide trap is shown to be a strong function of the substrate bias. From the analysis of the experimental results considering surface quantization effects follows that the variation of (E with U_BS is caused by the change in both the inversion layer surface charge density N_s and in the surface electric field F_s that influences the distance between the centroid of the inversion layer and the interface. In fact, it will be demonstrated that (E can be expressed in function of a single parameter (N_sF_s²). Finally, the impact of the substrate bias on the other parameters, i.e., the amplitude (I, the emission time constant F_e and the distance d of the trap from the interface, will also be addressed.     

Loss of atom interference due to a random phase

We suggest a model where the influence of an environment on the atom interference is associated with a random phase. The model consists of sending a two-level state atom through two cavities, both containing a standing wave field in the Bragg regime and Raman–Nath regime, respectively. In view of this model, we can visualize the loss of interference fringes if the randomness of the phase increases, and the restoration of the pattern when it decreases, as which-path information. Then, the controllable random noise acts as a decoherence that would destroy the quantum features.     

A restricted random walk on a one-dimensional random chain

It is found that under some special conditions the inverse velocity for a restricted random walk diverges even though it is finite for the corresponding unrestricted walk. This leads to an anomalous t^z (0<z<1) behaviour for the mean distance travelled in time t.     

Vibration of a beam due to a random stream of moving forces with random velocity

The problem of dynamic response of a beam to the passage of a train of concentrated forces with random amplitudes and velocities is considered. Force arrivals at the beam are assumed to constitute the point stochastic process of events. Thus, the excitation process is an idealization of vehicular traffic loads on a bridge. An analytical technique is developed to determine the response of the beam. Explicit expressions for the expected value and the variance of the beam deflection are provided. As an example, the response of a beam to a stationary stream of forces is determined for some practical situations, and discussed.     

Criticality without self-similarity: a 2D system with random long-range hopping

We consider a simple model of quantum disorder in two dimensions, characterized by a long-range site-to-site hopping. The system undergoes a metal–insulator transition--its eigenfunctions change from being extended to being localized. We demonstrate that at the point of the transition the nature of the eigenfunctions depends crucially on the magnitude of the hopping amplitude. At small amplitudes they are strongly multifractal. In the opposite limit of large amplitudes, the eigenfunctions do not become fractal. Their density moments do not scale as a power of the system size; instead our result suggests a power of the logarithm of the system size. In this regard, the transition differs from a similar one in the one-dimensional version of the same system, as well as from the conventional Anderson transition in more than two dimensions.     

Random telegraph signal noise simulation of decanano MOSFETs subject to atomic scale structure variation

As MOSFETs shrink into the decanano regime it is predicted that random telegraph signals (RTS), resulting from trapping events in defect states near the Si/SiO₂ interface, will significantly affect analogue and digital circuit performance. At these same scales, intrinsic parameter fluctuations introduced by atomic differences between devices will also be significant. In this work, a methodology based on 3D simulation is developed which can correctly model RTS noise in the time and frequency domain in the presence of random discrete dopants. The approach is illustrated with results obtained for 30×30  nm devices. We find that atomicity can significantly increase RTS magnitude in devices with particular doping configurations, and ensemble average RTS effects vary markedly from those predicted on an assumption of continuous doping.     

Statistical fluctuations for the noise current from random telegraph signals in semiconductor devices: Monte Carlo computer simulations and best fits

Random Telegraph Signals (RTS) has become a major source of variability in the electrical behavior of modern transistors. The major contribution of this work is a new model based on a Monte Carlo algorithm for the mechanisms leading to RTS noise in semiconductor devices. To describe the statistical sample noise current produced by Monte Carlo simulations we experiment with many possible fits using different functions. In order to perform this fitting we follow two distinct approaches: (a) by calculating the sampling moments and by direct substitution in assumed distributions and (b) by performing a non-linear fit using the Levenberg Marquardt algorithm. Our results show a breaking of gaussianity for the nanometer dimensions of deeply scaled technologies, and we show that the ECS peak function is the most appropriate distribution to fit suitably the data for these dimensions. Another relevant contribution is the study of how ballistic effects can change the current distribution. The results indicate an enlargement of the average and variance of the total current when ballistic effects are considered, which are analytically expressed as a function of relevant physical parameters of the semiconductor device.