A Spin - 3/2 Ising Model on a Square Lattice

The spin - 3/2 Ising model on a square lattice is investigated. It is shown that this model is reducible to an eight - vertex model on a surface in the parameter space spanned by coupling constants J, K, L and M. It is shown that this model is equivalent to an exactly solvable free fermion model along two lines in the parameter space.Comment: LaTeX, 7 pages, 1 figure upon request; JETP Letters, in pres

Lattice model theory of the equation of state covering the gas, liquid, and solid phases

The three stable states of matter and the corresponding phase transitions were obtained with a single model. Patterned after Lennard-Jones and Devonshires's theory, a simple cubic lattice model containing two fcc sublattices (alpha and beta) is adopted. The interatomic potential is taken to be the Lennard-Jones (6-12) potential. Employing the cluster variation method, the Weiss and the pair approximations on the lattice gas failed to give the correct phase diagrams. Hybrid approximations were devised to describe the lattice term in the free energy. A lattice vibration term corresponding to a free volume correction is included semi-phenomenologically. The combinations of the lattice part and the free volume part yield the three states and the proper phase diagrams. To determine the coexistence regions, the equalities of the pressure and Gibbs free energy per molecule of the coexisting phases were utilized. The ordered branch of the free energy gives rise to the solid phase while the disordered branch yields the gas and liquid phases. It is observed that the triple point and the critical point quantities, the phase diagrams and the coexistence regions plotted are in good agreement with the experimental values and graphs for argon

Exact location of the multicritical point for finite-dimensional spin glasses: A conjecture

We present a conjecture on the exact location of the multicritical point in the phase diagram of spin glass models in finite dimensions. By generalizing our previous work, we combine duality and gauge symmetry for replicated random systems to derive formulas which make it possible to understand all the relevant available numerical results in a unified way. The method applies to non-self-dual lattices as well as to self dual cases, in the former case of which we derive a relation for a pair of values of multicritical points for mutually dual lattices. The examples include the +-J and Gaussian Ising spin glasses on the square, hexagonal and triangular lattices, the Potts and Z_q models with chiral randomness on these lattices, and the three-dimensional +-J Ising spin glass and the random plaquette gauge model.Comment: 27 pages, 3 figure

Naive mean field approximation for image restoration

We attempt image restoration in the framework of the Baysian inference. Recently, it has been shown that under a certain criterion the MAP (Maximum A Posterior) estimate, which corresponds to the minimization of energy, can be outperformed by the MPM (Maximizer of the Posterior Marginals) estimate, which is equivalent to a finite-temperature decoding method. Since a lot of computational time is needed for the MPM estimate to calculate the thermal averages, the mean field method, which is a deterministic algorithm, is often utilized to avoid this difficulty. We present a statistical-mechanical analysis of naive mean field approximation in the framework of image restoration. We compare our theoretical results with those of computer simulation, and investigate the potential of naive mean field approximation.Comment: 9 pages, 11 figure

Low-frequency noise assessment of work function engineering cap layers in high-k gate stacks

Engineering the effective work function of scaled-down devices is commonly achieved by the implementation of capping layers in the gate stack. Typical cap layers are Al2O3 for pMOSFETs and La-oxide or Mg for nMOSFETs. Besides introducing a dipole layer at the SiO2/high-κ interface, the in-diffusion of the metal ions may lead to either passivation or generation of traps in the SiO2/high-κ layer. This paper uses low frequency noise studies to determine the impact of capping layers on the quality of the SiO2/HfO2 gate stacks. The influence on the trap profiles of different types of cap layers, different locations of the cap layer (below or on top of the HfO2 dielectric) and the impact of different thermal budgets, typically used for the fabrication of Dynamic Random Access Memory (DRAM) logic devices, are investigated. The differences between several metal oxides are outlined and discussed

Effects of Error-Based Simulation as a Counterexample for Correcting MIF Misconception

MIF (Motion Implies a Force) misconception is commonly observed in elementary mechanics learning where students think some force is applied to moving objects. This paper reports a practical use of Error-based Simulation (EBS) for correcting students’ MIF misconceptions in a junior high school and a technical college. EBS is a method to generate a phenomenon by using stu-dents’ erroneous idea (e.g., if a student thinks forward force applied to a skater traveling straight on ice at a constant velocity, EBS shows the skater acceler-ates). Such a phenomenon is supposed to work as a counterexample to students’ misconception. In the practice, students first worked on pre-test of five prob-lems (called ‘learning task’), in each of which they drew all the forces applied to objects in a mechanical situation. They then worked on the same problems on system where EBSs were shown based on their answer. They last worked on post-test of the previous plus four new problems (called ‘transfer task’). As a result, in both schools, the numbers of MIF-answers (the erroneous answers supposed due to MIF misconception) in learning task decreased significantly between pre-test and post-test. Effect sizes of the decrease of MIF-answers were larger than that of other erroneous answers. Additionally, the percentages of MIF-answers to the whole erroneous answers in transfer task were much lower than those in learning task. These results suggest learning with EBS not only has the effect on the resolution of MIF misconception, but also promoted the correction of errors in conceptual level.'Artificial Intelligence in Education' 18th International Conference, AIED 2017, Wuhan, China, June 28 – July 1, 2017, Proceeding

Impact of Hot Carrier Aging on Random Telegraph Noise and Within a Device Fluctuation

For nanometer MOSFETs, charging and discharging a single trap induces random telegraph noise (RTN). When there are more than a few traps, RTN signal becomes complex and appears as within a device fluctuation (WDF). RTN/WDF causes jitters in switch timing and is a major challenge to low power circuits. In addition to RTN/WDF, devices also age. The interaction between RTN/WDF and aging is of importance and not fully understood. Some researchers reported aging increasing RTN/WDF, while others showed RTN/WDF being hardly affected by aging. The objective of this work is to investigate the impact of hot carrier aging (HCA) on the RTN/WDF of nMOSFETs. For devices of average RTN/WDF, it is found that the effect of HCA is generally modest. For devices of abnormally high RTN/WDF, however, for the first time, we report HCA reducing RTN/WDF substantially (>50%). This reduction originates from either a change of current distribution or defect losses