Analysis Of The Energy Quantization Effects On Single Electron Inverter Performance Through Noise Margin Modeling

Possible integration of Single Electron Transistor (SET) with CMOS technology is making the study of semiconductor SET more important than the metallic SET and consequently, the study of energy quantization effects on semiconductor SET devices and circuits is gaining significance. In this paper, for the first time, the effects of energy quantization on SET inverter performance are examined through analytical modeling and Monte Carlo simulations. It is observed that the primary effect of energy quantization is to change the Coulomb Blockade region and drain current of SET devices and as a result affects the noise margin, power dissipation, and the propagation delay of SET inverter. A new model for the noise margin of SET inverter is proposed which includes the energy quantization effects. Using the noise margin as a metric, the robustness of SET inverter is studied against the effects of energy quantization. It is shown that SET inverter designed with CT : CG = 1/3 (where CT and CG are tunnel junction and gate capacitances respectively) offers maximum robustness against energy quantization.

Resistance Noise in Electrically Biased Bilayer Graphene

We demonstrate that the low-frequency resistance fluctuations, or noise, in bilayer graphene are strongly connected to its band structure and display a minimum when the gap between the conduction and valence band is zero. Using double-gated bilayer graphene devices we have tuned the zero gap and charge neutrality points independently, which offers a versatile mechanism to investigate the low-energy band structure, charge localization, and screening properties of bilayer graphene.

Effect of curve crossing on absorption and resonance Raman spectra: analytical treatment for delta-function coupling in parabolic potentials

We propose an exactly solvable model for the two-state curve-crossing problem. Our model assumes the coupling to be a delta function. It is used to calculate the effect of curve crossing on the electronic absorption spectrum and the resonance Raman excitation profile.

Frictional response of fatty acids on steel

Self-assembled monolayers of fatty acids were formed on stainless steel by room-temperature solution deposition. The acids are covalently bound to the Surface as carboxylate in a bidentate manner. To explore the effect Of Saturation in the carbon backbone on friction in sliding tribology, we Study the response of saturated stearic acid (SA) and unsaturated linoleic acid (LA) as self-assembled monolayers using lateral force microscopy and nanotribometry and when the molecules are dispersed in hexadecane, using pin-on-disc tribometry. Over a very wide range (10 MPa-2.5 GPa) of contact pressures it is consistently demonstrated that the unsaturated linoleic acid molecules yield friction which is significantly lower than that of the saturated stearic acid. it is argued, using density functional theory predictions and XPS of slid track, that when the molecular backbone of unsaturated fatty acids are tilted and pressed strongly by a probe, in tribological contact, the high charge density of the double bond region of the backbone allows coupling with the steel Substrate. The interaction yields a low friction carboxylate soap film on the substrate. The saturated fatty acid does not show this effect.

Mechanism of coupling periodate-oxidized nucleosides to proteins

This paper describes a mechanism of coupling periodate-oxidized nucleosides to proteins. Each of the dialdehyde groups of a periodate-oxidized nucleoside is shown to couple to lysine residues on different protein molecules through Schiff bases, thereby cross-linking different protein molecules, forming a polymer. This is in contrast to the previous model in which nucleosides were suggested to couple to proteins through a morpholine structure. The cross-linked structure of the nucleoside-antigen, significantly different when compared to the native protein, may affect the specificity and the efficiency of antibody production.

Ocean atmosphere coupling over monsoon regions

In monsoon regions, the seasonal migration of the intertropical convergence zone (ITCZ) is manifested as a seasonal reversal of winds. Most of the summer monsoon rainfall over India occurs owing to synoptic and large-scale convection associated with the continental ITCZ (Fig. 1). We have investigated the interaction between these large-scale convective systems and the ocean over which they are generated1â3, concentrating on the relationship between organized convection over the Indian Ocean and sea surface temperature (SST). We report here that on a monthly basis the degree of cloudiness correlates well with SST for the relatively colder oceans, but when SST is maintained above 28 °C it ceases to be an important factor in determining the variability of cloudiness. Over the major regions of convection east of 70°E, which are warm year after year, the observed cloudiness cannot be correlated with variations in SST.

Theoretical evidence and chemical origin of the magnetism-dependent electrostructural coupling in La2NiMnO6

Using first-principles density-functional calculations, we determine and analyze the Born effective charges Z(*) that describe the coupling between electric field and atomic displacements for ferromagnetic double-perovskite compound, La2NiMnO6. We find that th Born effective charge matrix of Ni in La2NiMnO6, has an anomalously large antisymmetric component, whose magnitude reduces substantially upon change in the magnetic ordering between Ni and Mn, showing it to be a magnetism-dependent electrostructural coupling. We use a local picture of the electronic structure obtained with Wannier functions, along with its band-by-band decomposition to determine its electronic origin.

Atmospheric Noise on the Bispectrum in Optical Speckle Interferometry

Based on a simple picture of speckle phenomena in optical interferometry it is shown that the recent signal-to-noise ratio estimate for the so called bispectrum, due to Wirnitzer (1985), does not possess the right limit when photon statistics is unimportant. In this wave-limit, which is true for bright sources, his calculations over-estimate the signal-to-noise ratio for the bispectrum by a factor of the order of the square root of the number of speckles.

Invited paper Application of the least mean fourth (LMF) adaptive algorithm to signals associated with gaussian noise

This paper considers the applicability of the least mean fourth (LM F) power gradient adaptation criteria with 'advantage' for signals associated with gaussian noise, the associated noise power estimate not being known. The proposed method, as an adaptive spectral estimator, is found to provide superior performance than the least mean square (LMS) adaptation for the same (or even lower) speed of convergence for signals having sufficiently high signal-to-gaussian noise ratio. The results include comparison of the performance of the LMS-tapped delay line, LMF-tapped delay line, LMS-lattice and LMF-lattice algorithms, with the Burg's block data method as reference. The signals, like sinusoids with noise and stochastic signals like EEG, are considered in this study.

Fluctuation phenomena in electrochemistry part II. Modelling the noise sources

A discussion of the modelling of the primary and secondary noise sources introduced in the formalism of fluctuation phenomena in a previous report is presented. It is illustrated that the generalisation of the modelling of noise sources in mass transport as given by Tyagai is limited in its applicability. A general procedure for the same is discussed in detail.

Strong-coupling expansion for the momentum distribution of the Bose-Hubbard model with benchmarking against exact numerical results

A strong-coupling expansion for the Green's functions, self-energies, and correlation functions of the Bose-Hubbard model is developed. We illustrate the general formalism, which includes all possible (normal-phase) inhomogeneous effects in the formalism, such as disorder or a trap potential, as well as effects of thermal excitations. The expansion is then employed to calculate the momentum distribution of the bosons in the Mott phase for an infinite homogeneous periodic system at zero temperature through third order in the hopping. By using scaling theory for the critical behavior at zero momentum and at the critical value of the hopping for the Mott insulator–to–superfluid transition along with a generalization of the random-phase-approximation-like form for the momentum distribution, we are able to extrapolate the series to infinite order and produce very accurate quantitative results for the momentum distribution in a simple functional form for one, two, and three dimensions. The accuracy is better in higher dimensions and is on the order of a few percent relative error everywhere except close to the critical value of the hopping divided by the on-site repulsion. In addition, we find simple phenomenological expressions for the Mott-phase lobes in two and three dimensions which are much more accurate than the truncated strong-coupling expansions and any other analytic approximation we are aware of. The strong-coupling expansions and scaling-theory results are benchmarked against numerically exact quantum Monte Carlo simulations in two and three dimensions and against density-matrix renormalization-group calculations in one dimension. These analytic expressions will be useful for quick comparison of experimental results to theory and in many cases can bypass the need for expensive numerical simulations.

Effect of substrate temperature on the physical properties of dc magnetron sputtered CuAlO2 films

Copper aluminum oxide films were prepared by direct current (dc) reactive magnetron sputtering under various substrate temperatures in the range of 303–648 K and systematically studied their physical properties. The physical properties of the films were strongly affected by the substrate temperature. The films formed at substrate temperatures <373 K were amorphous while those deposited at higher substrate temperatures (≥373 K) were polycrystalline in nature. The electrical properties of the films enhanced with substrate temperature due to the improved crystallinity. The Hall mobility of 9.4 cm2/V s and carrier concentration of 3.5 × 1017 cm−3 were obtained at the substrate temperature of 573 K. The optical band gap of the films decreased from 3.87 to 3.46 eV with the increase of substrate temperature from 373 to 573 K.

Comparison Of If Estimation Methods For Noise Robustness

Non-stationary signal modeling is a well addressed problem in the literature. Many methods have been proposed to model non-stationary signals such as time varying linear prediction and AM-FM modeling, the later being more popular. Estimation techniques to determine the AM-FM components of narrow-band signal, such as Hilbert transform, DESA1, DESA2, auditory processing approach, ZC approach, etc., are prevalent but their robustness to noise is not clearly addressed in the literature. This is critical for most practical applications, such as in communications. We explore the robustness of different AM-FM estimators in the presence of white Gaussian noise. Also, we have proposed three new methods for IF estimation based on non-uniform samples of the signal and multi-resolution analysis. Experimental results show that ZC based methods give better results than the popular methods such as DESA in clean condition as well as noisy condition.

Ultra-low conductivity noise in metallic nanowires

By modifying the electrodeposition technique, we have stabilized the silver nanowires (AgNWs) in high-energy hexagonal closed packed (hcp)structure. The conductivity noise measurements show that the noise magnitude in hcp silver nanowires is several orders of magnitude smaller than that of face centered cubic (fcc) silver nanowires, which is obtained by standard over potential lectrodeposition (OPD)technique. The reduction of noise can be attributed to the restricted dislocation dynamics in hcp AgNWs due to the presence of less number of slip systems. Temperature dependent noise measurements show that the noise magnitude in hcp AgNWs is weakly temperature dependent while in fcc AgNWs it is strong function of temperature.