Entropic effects on the size dependence of cluster structure

We show that the vibrational entropy can play a crucial role in determining the equilibrium structure of clusters by constructing structural phase diagrams showing how the structure depends upon both size and temperature. These phase diagrams are obtained for example rare gas and metal clusters.     

Entropic torque

Quantitative predictions are presented of a depletion-induced torque and force acting on a single colloidal hard rod immersed in a solvent of hard spheres close to a planar hard wall. This torque and force, which are entirely of entropic origin, may play an important role for the key-lock principle, according to which a biological macromolecule (the key) is functional only in a particular orientation with respect to a cavity (the lock).     

熵测不准关系与光场的熵压缩

用熵作为光场量子涨落的量度,根据熵测不准关系,建立了熵压缩的概念,具体研究了光场与原子相互作用时的熵压缩,结果显示,熵压缩实现了对光场压缩效应的高灵敏量度。     

Entropic uncertainty relation

Shannon's entropy is used for the formulation of the uncertainty relation. Two concrete examples are solved: the case of dynamically commuting continuous observables, and the case of theh/2 spin projections.     

Entropic uncertainty relations

New entropic uncertainty relations for angle-angular momentum and position-momentum, derived recently by Partovi, are related to older relations of a similar type, which were proved by Bialynicki-Birula and Mycielski. Significantly improved lower bounds are obtained in both cases.     

Dilatonic Entropic Force

We show in detail that the entropic force of the static spherically symmetric spacetimes with unusual asymptotics can be calculated through the Verlinde’s arguments. We introduce three different holographic screen candidates, which are first employed thoroughly by Myung and Kim [Phys. Rev. D 81, 105012 (2010)] for Schwarzschild black hole solutions, in order to identify the entropic force arising between a charged dilaton black hole and a test particle. The significance of the dilaton parameter on the entropic force is highlighted, and shown graphically.     

Entropic stochastic resonance

We present a novel scheme for the appearance of stochastic resonance when the dynamics of a Brownian particle takes place in a confined medium. The presence of uneven boundaries, giving rise to an entropic contribution to the potential, may upon application of a periodic driving force result in an increase of the spectral amplification at an optimum value of the ambient noise level. The entropic stochastic resonance, characteristic of small-scale systems, may constitute a useful mechanism for the manipulation and control of single molecules and nanodevices.     

Entropic accelerating universe

To accommodate the observed accelerated expansion of the universe, one popular idea is to invoke a driving term in the Friedmann–Lemaître equation of dark energy which must then comprise 70% of the present cosmological energy density. We propose an alternative interpretation which takes into account the entropy and temperature intrinsic to the horizon of the universe due to the information holographically stored there. Dark energy is thereby obviated and the acceleration is due to an entropic force naturally arising from the information storage on the horizon surface screen. We consider an additional quantitative approach inspired by surface terms in general relativity and show that this leads to the entropic accelerating universe.     

Polarization effects in Drell-Yan processes

Effects of polarization of hadrons and constituent quarks in Drell-Yan processes are considered; they are one of the most efficient tools for investigation of the quark structure of hadrons. Special attention is paid to such important parton distribution functions as the transversity and T-odd Sivers and Boer—Mulders functions whose study is necessary for understanding the effects connected with the nonzero transverse component of the quark momentum. An original method for direct extraction of transversity and Boer—Mulders function in the proton from the data on Drell—Yan processes, in which a maximum of one hadron in the initial state is transversely polarized, is presented. This method possesses a number of important advantages. The method is applied both to Drell—Yan processes with a valence antiquark (antiproton-proton and pion-proton collisions) and with a sea antiquark (proton-proton, proton-deuteron, and deuteron-deuteron collisions). Theoretical estimates of asymmetries and cross sections for setups at RHIC (BNL, US), NICA (JINR, Russia), COMPASS (CERN, Switzerland), PAX (GSI, Germany), and J-PARC (Japan) are presented for evaluation of the measurability of transversity and T-odd distributions. These theoretical estimates are accompanied by calculations of statistical uncertainties for measured asymmetries using the new Monte Carlo generator of Drell—Yan events. The duality of Drell—Yan processes and those of production of J/Φ resonance is studied, and it may allow one to considerably reduce statistical uncertainties of parton distributions. Kinematical conditions, for which this duality can be observed, are evaluated.     

Many-electron effects in atomic processes

The major role of the collectivization of electrons in atoms and quasiatomic formations is demonstrated. The random-phase approximation with exchange, which permits allowance for these effects, is discussed in detail. The need to extend the scope of this approximation when some processes are considered, which is achieved by combining it with perturbation theory, is noted. The role of the collective effects is illustrated by the results of recently performed calculations of the photoionization cross sections of atomic iodine and its positive and negative ions, the single-electron ionization of Xe⁺, resonance-enhanced photon emission in collisions of electrons with atoms and quasiatomic formations, the nondipole corrections to the angular distribution of photoelectrons, and the probabilities of two-electron transitions in which all the energy is released in the form of a single photon. Zh. Tekh. Fiz. 69, 31–35 (September 1999)     

Entropic phase separation in polymer-microemulsion networks

We study theoretically a model system of a transient network of microemulsion droplets connected by telechelic polymers and explain recent experimental findings. Despite the absence of any specific interactions between either the droplets or polymer chains, we predict that as the number of polymers per drop is increased, the system undergoes a first-order phase separation into a dense, highly connected phase, in equilibrium with dilute droplets, decorated by polymer loops. The phase transition is purely entropic and is driven by the interplay between the translational entropy of the drops and the configurational entropy of the polymer connections between them. Because it is dominated by entropic effects, the phase behavior of the system is extremely robust and is independent of the detailed properties of either polymers or drops.     

Elastic Entropic Forces in Polymer Deformation

The entropic nature of elasticity of long molecular chains and reticulated materials is discussed concerning the analysis of flows of polymer melts and elastomer deformation in the framework of Frenkel–Eyring molecular kinetic theory. Deformation curves are calculated in line with the simple viscoelasticity models where the activation energy of viscous flow depends on the magnitude of elastic entropic forces of the stretched macromolecules. The interconnections between deformation processes and the structure of elastomer networks, as well as their mutual influence on each other, are considered.     

Entropic uncertainty relation in neutrino oscillations

The European Physical Journal C - We study the isentropic evolution of the matter produced in relativistic heavy-ion collisions for various values of the entropy-per-baryon ratio of interest for...     

Interaction between antimony atoms and micropores in silicon

The interaction between Sb atoms and micropores of a getter layer in silicon is studied. The getter layer was obtained via implantation of Sb⁺ ions into silicon and subsequent heat treatment processes. The antimony atoms located in the vicinity of micropores are captured by micropores during gettering annealing and lose its electrical activity. The activation energy of capture process to the pores for antimony is lower than that of antimony diffusion in silicon deformation fields around microvoids on the diffusion process.     

Entrance channel effects in fusion-evaporation processes

The effect of shape equilibration on particle emission in fusion reactions is thoroughly studied. Following a detailed evaluation of the various time scales a microscopic dynamical picture of the fusion path is coupled to a statistical decay probability at different time steps. It is shown that excitation energy and deformation of the compound system are influencing the emission pattern of charged particles and Giant Dipole photons. A quantitative analysis is performed for a ¹⁶⁴Yb compound system formed via O + Sm (mass asymmetric) and Ni + Mo (mass symmetric) channels at various excitation energies. In the mass-symmetric case interesting effects are revealed on spectra and angular distributions of emitted particles, particularly for α's, protons and Giant Dipole photons. Experiments are suggested to directly measure these “pre-equilibrium” contributions leading to new information on very exotic hyperdeformed nuclear systems.     

Entropic uncertainty relation in de Sitter space

The uncertainty principle restricts our ability to simultaneously predict the measurement outcomes of two incompatible observables of a quantum particle. However, this uncertainty could be reduced and quantified by a new Entropic Uncertainty Relation (EUR). By the open quantum system approach, we explore how the nature of de Sitter space affects the EUR. When the quantum memory A$A$ freely falls in the de Sitter space, we demonstrate that the entropic uncertainty acquires an increase resulting from a thermal bath with the Gibbons–Hawking temperature. And for the static case, we find that the temperature coming from both the intrinsic thermal nature of the de Sitter space and the Unruh effect associated with the proper acceleration of A$A$ also brings effect on entropic uncertainty, and the higher the temperature, the greater the uncertainty and the quicker the uncertainty reaches the maximal value. And finally the possible mechanism behind this phenomenon is also explored.     

Entropic Fluctuations in Thermally Driven Harmonic Networks

Journal of Statistical Physics - We consider a general network of harmonic oscillators driven out of thermal equilibrium by coupling to several heat reservoirs at different temperatures. The action...     

Entropic Uncertainty in Neutrino and Meson Systems

The dynamics of quantum‐memory‐assisted entropic uncertainty for the closed neutrino system in the context of two flavor oscillations and the meson system within the framework of open quantum system are investigated. It is found that the entropic uncertainty exists in close relation with the quantum correlation, and growing quantum correlation can decrease the uncertainty. The oscillatory behaviors of entropic uncertainty in neutrino system brought about by neutrino oscillating property are different from the decaying behaviors of entropic uncertainty in meson system induced by the meson decaying nature. In addition, the entropic uncertainty is always equal to its lower bound in the two subatomic systems. This study would throw light on the particle behavior characteristics of high energy physics, and may be useful to the tasks of quantum information‐processing implemented with subatomic system since the uncertainty principle plays vital role in quantum information science and technology.