A brief review: effects of resonant magnetic perturbation on classical and neoclassical tearing modes in tokamaks

This paper reviews the effects of resonant magnetic perturbation (RMP) on classical tearing modes (TMs) and neoclassical tearing modes (NTMs) from the theory, experimental discovery and numerical results with a focus on four major aspects: (i) mode mitigation, where the TM/NTM is totally suppressed or partly mitigated by the use of RMP; (ii) mode penetration, which means a linearly stable TM/NTM triggered by the externally applied RMP; (iii) mode locking, namely an existing rotating magnetic island braked and finally stopped by the RMP; (iv) mode unlocking, as the name suggests, it is the reverse of the mode locking process. The key mechanism and physical picture of above phenomena are revealed and summarized.

Verification of influence of tail states and interface states on sub-threshold swing of Si n-channel MOSFETs over a temperature range of 4K to 300K

We experimentally characterize SS of Si nMOSFETs with a substrate boron concentration of 2 × 1016 cm-3 as a function of IDS and temperatures from 4 to 300 K to verify the validity of the physical model of SS. The minimum SS are obtained around 4 mV/dec. at 4 K. The physical model including band tail states and interface states is employed to represent the experimental SS from 4 to 300 K. The impact of each parameter included in the physical model on SS behavior is examined by changing the value of the parameters in simulation. It is found that the proposed physical model can quantitatively represent experimental SS in a wide range of IDS and temperature under a given set of the parameters regarding the band tail states and the interface states. This finding indicates the validity of the present physical model and the correctness of the physical picture.

Problem of energy scale in rigid triaxial rotor model

The problem of mismatching of the level energies, in the ground band and the [Formula: see text]-band of triaxially deformed atomic nuclei, as predicted in the rigid triaxial rotor (RTR) approximation of Davydov and Filippov (DF) model, with experiment, is well known. Here, we illustrate the solutions suggested in the literature, and the deviations observed in the converted energy values, from the experiment. We analyze the source of problem of this mismatch with experiment. This enables a physical picture of the DF (or RTR) model spectra. Our analysis will help in understanding the merits and the limitation of the RTR model in this respect.

Characterization of Monte Carlo Dynamic/Kinetic Properties of Local Structure in Bond Fluctuation Model of Polymer System

We report the results of the characterization of local Monte Carlo (MC) dynamics of an equilibrium bond fluctuation model polymer matrix (BFM), in time interval typical for MC simulations of non-linear optical phenomena in host-guest systems. The study contributes to the physical picture of the dynamical aspects of quasi-binary mosaic states characterized previously in the static regime. The polymer dynamics was studied at three temperatures (below, above and close to the glass transition), using time-dependent generalization of the static parameters which characterize local free volume and local mobility of the matrix. Those parameters play the central role in the kinetic MC model of host-guest systems. The analysis was done in terms of the probability distributions of instantaneous and time-averaged local parameters. The main result is the characterization of time scales characteristic of various local structural processes. Slowing down effects close to the glass transition are clearly marked. The approach yields an elegant geometric criterion for the glass transition temperature. A simplified quantitative physical picture of the dynamics of guest molecules dispersed in BFM matrix at low temperatures offers a starting point for stochastic modeling of host-guest systems.

Colloidal Soft Matter Physics

Colloidal soft matter is a class of materials that exhibit rich equilibrium and non-equilibrium 0thermodynamic properties, it self-assembles (spontaneously or driven externally) to form a large diversity of structures, and its constituents display an interesting and complex transport behavior. In this contribution, we review the essential aspects and the modern challenges of Colloidal SoftMatter Physics. Our main goal is to provide a balanced discussion of the various facets of this highly multidisciplinary field, including experiments, theoretical approximations and models for molecular simulations, so that readers with various backgrounds could get both the basics and a broader, more detailed physical picture of the field. To this end, we first put emphasis on the colloidal physics, which allows us to understand the main driving (molecular and thermodynamic) forces between colloids that give rise to a wide range of physical phenomena. We also draw attention to some particular problems and areas of opportunity in Colloidal Soft Matter Physics that represent promising perspectives for future investigations.

Creep Motion of Elastic Interfaces Driven in a Disordered Landscape

The thermally activated creep motion of an elastic interface weakly driven on a disordered landscape is one of the best examples of glassy universal dynamics. Its understanding has evolved over the past 30 years thanks to a fruitful interplay among elegant scaling arguments, sophisticated analytical calculations, efficient optimization algorithms, and creative experiments. In this article, starting from the pioneer arguments, we review the main theoretical and experimental results that lead to the current physical picture of the creep regime. In particular, we discuss recent works unveiling the collective nature of such ultraslow motion in terms of elementary activated events. We show that these events control the mean velocity of the interface and cluster into “creep avalanches” statistically similar to the deterministic avalanches observed at the depinning critical threshold. The associated spatiotemporal patterns of activated events have been recently observed in experiments with magnetic domain walls. The emergent physical picture is expected to be relevant for a large family of disordered systems presenting thermally activated dynamics.

From soft to hard radiation: the role of multiple scatterings in medium-induced gluon emissions

A proper understanding of the physics of medium-induced gluon emissions is known to be of critical importance to describe the properties of strongly interacting matter under extreme conditions. In this regard, many theoretical efforts have been directed towards obtaining analytical calculations which might help us discerning the underlying physical picture and the dominant dynamics for different regimes. These analytical approaches rely on approximations whose validity is analyzed here by comparing their results with a recently developed numerical evaluation which includes all-order resummation of multiple scatterings. More specifically, by quantitatively comparing the energy spectrum and rates, we observe that three different regimes — each with its corresponding physical picture — emerge naturally from the equations: the high-energy regime where the emission process is dominated by a single hard scattering, the intermediate-energy regime where coherence effects among multiple scatterings become fundamental, and the low-energy regime where the dynamics is again dominated by a single scattering but where one must include the suppression factor due to the probability of not having any further scatterings (which is obtained through the resummation of virtual terms).

Deconstructing Frame-Dragging

The vorticity of world-lines of observers associated with the rotation of a massive body was reported by Lense and Thirring more than a century ago. In their example, the frame-dragging effect induced by the vorticity is directly (explicitly) related to the rotation of the source. However, in many other cases, it is not so, and the origin of vorticity remains obscure and difficult to identify. Accordingly, in order to unravel this issue, and looking for the ultimate origin of vorticity associated to frame-dragging, we analyze in this manuscript very different scenarios where the frame-dragging effect is present. Specifically, we consider general vacuum stationary spacetimes, general electro-vacuum spacetimes, radiating electro-vacuum spacetimes, and Bondi–Sachs radiating spacetimes. We identify the physical quantities present in all these cases, which determine the vorticity and may legitimately be considered as responsible for the frame-dragging. Doing so, we provide a comprehensive, physical picture of frame-dragging. Some observational consequences of our results are discussed.