Fluctuation Phenomena


Book Description

Studies in Statistical Mechanics, Volume VII: Fluctuation Phenomena Fluctuation explores different aspects of fluctuation behavior and their relation to microscopic processes and other phenomena, including the nucleation of a new phase following the quenching of a system into the coexistence region. It looks at phenomenological fluctuation theories, stochastic processes such as Markoff and momentless processes, and stochastic geometric aspects of amorphous solids. Comprised of five chapters, this volume begins with an overview of fluctuations and the Ehrenfest dog-flea model. It then turns to a discussion of density fluctuations in dilute gases, the Langevin theory of Brownian motion, and classical diffusion and random walks. It also systematically introduces the reader to the statistical mechanical theory of the kinetics of phase transitions, the molecular theory of metastability, and multidimensional continuous time random walks, along with the effect of boundaries and defects onf stochastic processes. In addition, it describes the phenomenological theory of the kinetics of nucleation and its application to nucleation, spinodal decomposition, and condensation. Other chapters focus on a stochastic model for the kinetics of phase transitions, the physical ideas used in theories of metastability, and the importance of dynamics in the study of metastability. The book explains how to estimate the escape rate and describes the statistical mechanics of clusters before concluding with a discussion of slowly-varying ensembles. This book is a valuable resource for students, physicists, and researchers who want to gain more knowledge and learn about statistical mechanics in general and fluctuation phenomena in particular.




Fluctuation Phenomena in High Temperature Superconductors


Book Description

These Proceedings of a NATO-ARW (HTECH ARW 96 00 52) held at the International Center for Theoretical Physics, Trieste, Italy from Aug 5 till Aug 9, 1996 resulted from many discussions between various workers, concerning the need for a gathering of all (if possible) who were concerned about the subject of superconductivity fluctuations in High critical Temperature Superconductors (HTS). It appeared to many that the Skocpol-Tinkham work of 1975 had to be revitalized in view of the discovery of the new superconducting ceramics and the enormous amount of work having already taken place. The study of HTS is one of the most prominent research subject in solid state sciences. The understanding of the role of fluctuations is also thought to be necessary before technological applications since the fluctuations may destroy the superconducting state. The workshop discussions have touched upon (i) Superconducting fluctuations in the vicinity of the critical transition, (ii) Superconductivity fluctuations near the percolation transition, and (iii) Fluctuations of the vortex lattice at the lattice melting temperature. These topics served as initiators for a very great amount of discussions with many comments from the audience. More than forty "long lectures" and two "poster sessions" were held. Private discussions going unrecorded but obviously took place at many locations : lecture halls, staircases, cafetaria, bedrooms, bars, beach, . . .




The Physics of Nanoelectronics


Book Description

Advances in nanotechnology have allowed physicists and engineers to miniaturize electronic structures to the limit where finite-size related phenomena start to impact their properties. This book discusses such phenomena and models made for their description. The book starts from the semiclassical description of nonequilibrium effects, details the scattering theory used for quantum transport calculations, and explains the main interference effects. It also describes how to treat fluctuations and correlations, how interactions affect transport through small islands, and how superconductivity modifies these effects. The last two chapters describe new emerging fields related with graphene and nanoelectromechanics. The focus of the book is on the phenomena rather than formalism, but the book still explains in detail the main models constructed for these phenomena. It also introduces a number of electronic devices, including the single-electron transistor, the superconducting tunnel junction refrigerator, and the superconducting quantum bit.







Theory of Fluctuations in Superconductors


Book Description

This book presents a complete encyclopedia of superconducting fluctuations, summarising the last thirty-five years of work in the field. The first part of the book is devoted to an extended discussion of the Ginzburg-Landau phenomenology of fluctuations in its thermodynamical and time-dependent versions and its various applications. The second part deals with microscopic justification of the Ginzburg-Landau approach and presents the diagrammatic theory of fluctuations. The third part is devoted to a less-detailed review of the manifestation of fluctuations in observables: diamagnetism, magnetoconductivity, various tunneling characteristics, thermoelectricity, and NMR relaxation. The final chapters turn to the manifestation of fluctuations in unconventional superconducting systems: nanodrops, nanorings, Berezinsky-Kosterlitz-Thouless state, quantum phase transition between superconductor and insulator, and thermal and quantum fluctuations in weak superconducting systems. The book ends with a brief discussion on theories of high temperature superconductivity, where fluctuations appear as the possible protagonist of this exciting phenomenon.




Fluctuation Mechanisms in Superconductors


Book Description

Holger Bartolf discusses state-of-the-art detection concepts based on superconducting nanotechnology as well as sophisticated analytical formulæ that model dissipative fluctuation-phenomena in superconducting nanowire single-photon detectors. Such knowledge is desirable for the development of advanced devices which are designed to possess an intrinsic robustness against vortex-fluctuations and it provides the perspective for honorable fundamental science in condensed matter physics. Especially the nanowire detector allows for ultra-low noise detection of signals with single-photon sensitivity and GHz repetition rates. Such devices have a huge potential for future technological impact and might enable unique applications (e.g. high rate interplanetary deep-space data links from Mars to Earth).










Noise and Fluctuations


Book Description

An understanding of fluctuations and their role is both useful and fundamental to the study of physics. This concise study of random processes offers graduate students and research physicists a survey that encompasses both the relationship of Brownian Movement with statistical mechanics and the problem of irreversible processes. It outlines the basics of the physics involved, without the strictures of mathematical rigor. The three-part treatment starts with a general survey of Brownian Movement, including electrical Brownian Movement and "shot-noise," Part two explores correlation, frequency spectrum, and distribution function, with particular focus on application to Brownian Movement. The final section examines noise in electric currents, including noise in vacuum tubes and a random rectangular current. Frequent footnotes amplify the text, along with an extensive selection of Appendixes.




Fluctuating Nonlinear Oscillators


Book Description

The book provides a unifying insight into a broad range of phenomena displayed by vibrational systems of current interest. The chapters complement each other to give an account of the major fundamental results and applications in quantum information, condensed matter physics, and engineering.