Subject Grouping: Praxis

By P Blood
Oxford University Press

This book provides a comprehensive discussion of quantum confined semiconductor lasers, based on the author’s long and extensive experience in the field. In a pedagogical fashion, it takes the reader from the physics principles and processes exploited by lasers (giving a consistent treatment of both quantum-dot and quantum-well structures) to operation of the most advanced devices.

The text begins with a short historical account of the birth and development of lasers in general (called “maser” at the very beginning because restricted to microwaves), and the diode laser in particular. Thereafter, the book is organised into five sections. The first, dedicated to the diode laser, provides the framework for the whole volume. The second section describes the fundamental processes involved in the physics of lasers, a subject that is then treated in depth in the third part. The fourth section discusses the operation of laser devices and their characteristics (light-current curves, threshold current, efficiency, etc). Finally, the author tackles the important topics of recombination and optical gain, describing ways in which they can be measured on device structures and compared with theoretical predictions.

Full of detailed explanations, illustrations from model calculations and experimental observations, as well as a comprehensive set of exercises, the book is recommended to final-year undergraduate and PhD students, as well as researchers who are new to the field and need a complete overview of the subject.

By M Shibata
World Scientific

Numerical relativity is a field of theoretical physics in which Einstein’s equation and associated matter field equations are solved using computer calculations, because they are nonlinear partial-differential equations and therefore they cannot be solved analytically for general problems.

The purpose of this volume is to describe the techniques of numerical relativity and to report the knowledge obtained from the numerical simulations performed so far. The first chapter offers an overview of the basics of general relativity, gravitational waves and relativistic astrophysics, which are the background of numerical relativity. Then, in the first part of the book (chapters 2 to 7), the author discusses the most used formulations and numerical methods, while in the second part (chapters 8 to 11), he reports on representative numerical-relativity simulations and the knowledge derived from them.

Particular importance is given to the results obtained by applying these simulation techniques to the study of black-hole formation, binary compact objects, and the merger of binary neutron stars and black holes. New frontiers in numerical relativity are also touched on in the last two chapters.

By J Quaintance and H W Gould
World Scientific

Written by Henry Gould’s assistant Jocelyn Quaintance, this book is the result of the deep work and personal relationship between the great mathematician and the author. They met when Quaintance had recently graduated with a PhD, and was looking for a career in research and an advisor who could guide him. He had the luck to collaborate with Gould, who showed him his manuscripts: several handwritten volumes on combinatorial identities. Quaintance offered to edit a text collecting together all of that material, which led to the publication of this book.

The first eight chapters introduce readers to the special techniques that Gould used in proving his binomial identities. This first part is easily accessible to people who have taken basic courses in calculus and discrete mathematics. The second half of the book applies the techniques from the first part, and is particularly relevant for mathematics researchers. It focuses on the connection between various classes of Stirling numbers, and between them and Bernoulli numbers.

Some of the demonstrations presented in the volume represent the only systematic record of Gould’s results. As such, this book is a unique work that could appeal to a wide audience: from graduate students to specialists in enumerative combinatorics, to enthusiasts of Gould’s work.

By Y Liu
World Scientific

The challenge of developing more intense, shorter-pulse lasers has already seen outstanding results and opened up completely new perspectives. In fact, the next generation of very-high-power laser facilities will provide the opportunity to explore even ultrarelativistic and vacuum nonlinearity at unprecedented levels, moving towards a QCD regime. At the same time, during the last few years, attosecond physics has provided a new, intriguing way to visualise both atoms and molecules, and the electromagnetic-field structure of the excitation wave packet itself, because this time domain is comparable with the classical periods of electrons orbiting around the nucleus. This growing research field is so recent that the literature on the subject is not yet adequate: in this sense, this book partially fills the gap. It contains contributions from several Chinese groups, both experimental and theoretical, and reports on recent studies of bound electron and molecular nonlinearities. The content is organised over eight chapters and spans a broad range of topics of this specialist subject.

Strong-field tunnelling is a possible key to the ionisation of neutrals. It offers a sophisticated method to image and probe atomic and molecular quantum processes. In fact, the study of direct and rescattered (by the nucleus) electrons in the ionisation process is able to resolve orbitals; in this context, it becomes important to go beyond strong-field approximation, and to evaluate the contribution of the long-range Coulomb field generated by the ion in the electron dynamical evolution (chapter 1).

Direct and rescattered electrons can be recorded together as a reference wave and a signal wave, respectively: the interferential patterns constitute the analogue of optical holography, reconstructing the illuminated objects. It is possible to integrate the influence of the Coulomb field, either in a numerical solution of the time-dependent Schrödinger equation (TDSE) or in a more intuitive quantum-trajectories Monte Carlo method describing the formation mechanisms of the photoelectron angular distribution of above-threshold ionisation (chapter 2).

Dissociation is a basic process of physical chemistry and, before the advent of new ultrafast tools, seemed completely out of scientists’ control, because the typical timescale is below the femtosecond range. For an easier comparison of theoretical predictions and experimental results for a molecule interacting with a strong ultrashort laser pulse, it is necessary to start with the simplest systems – the hydrogen molecular ion H⁺₂. In chapter 3, on the basis of a numerical analysis of the related TDSE, the author suggests a pump–probe strategy to understand dissociation.

The theoretical discussion of double ionisation in a strong laser field is treated in chapters 4 and 5 for different kinds of atoms. In the case of high Z, the experiments show a different degree of correlation of the two expelled electrons, with respect to the low-Z case: this is due to the major importance of rescattering, as described by a semiclassical model. For the simpler systems H₂ and He, TDSE is a powerful tool for calculating all of the main features of double ionisation (total and differential cross-sections, recoil-ion momentum spectra, two electron angular distributions, and two electron-interference phenomena).

A promising application of strong-field excitation on atoms and molecules is high-order harmonics generation (HHG), usually providing a XUV comb with different harmonics at the same intensities, both in a single attosecond pulse and in a train of attosecond pulses, by a conversion of the light frequency from IR to the X-ray regime. This technique provides a tomographic image of molecular orbitals as an alternative to scanning tunnelling microscopy or angle-resolved photoelectron spectroscopy, as well as a way to study ultrafast electronic structures, electron dynamics and multichannel dynamics (chapters 6 and 7).

Finally, chapter 8 presents an interesting review of the properties of free electron laser radiation, showing how nuclear motion in photo-induced reactions can be monitored in real time, the electronic dynamics in molecular co-ordinates can be extracted, and the site-specific information in the structural dynamics of chemical reactions can be provided. The experiments are based on EUV pump–probe and optical pump-X-ray probe excitation techniques, and are located at FLASH (Hamburg) and LCLS (SLAC), respectively.

As a summary, the book is a useful update for people who are interested in the specialised field of the interaction of atoms and molecules with femtosecond or sub-femtosecond high-intensity fields. The comprehensive bibliography allows the reader to gain a more exhaustive view of the subject.

By T Iida and R I L Guthrie
Oxford University Press

Authored by two leading experts in the field, these books provide a complete review of the static and dynamic thermophysical properties of metallic liquids. Divided into two volumes, the first one (Fundamentals) is intended as an introductory text in which the basic topics are covered: the structure of metallic liquids, their thermodynamic properties, density, velocity of sound, surface tension, viscosity, diffusion, and electrical and thermal conductivities. Essential concepts about the methods used to measure these experimental data are also presented.

In the second volume (Predictive Models), the authors explain how to develop reliable models of liquid metals, starting from the essential conditions for a model to be truly predictive. They use a statistical approach to rate the validity of different models. On the basis of this assessment, the authors have compiled tables of predicted values for the thermophysical properties of metallic liquids, which are included in the book. A large amount of experimental data are also given.

The two books are particularly oriented to students of materials science and engineering, but also to research scientists and engineers engaged in liquid metallic processing. They collect a large amount of information and are written in a clear and readable way, therefore they are bound to become an essential reference for students and researchers involved in the field.

By M Bucchi and B Trench (eds)
Routledge

With scientists increasingly asked to engage the public and society-at-large with their research, and include outreach plans as part of grant applications, it helps to have a guide to various involvement possibilities and the research behind them. The second edition of the Routledge Handbook of Public Communication of Science and Technology (henceforth referred to as “the Handbook”) provides a thorough introduction to public engagement – or outreach, as it is sometimes called – through a varied collection of articles on the subject. In particular, it brings to attention the underlying issues associated with the old “deficit model of science communication”, which presupposes a knowledge deficit about science among the general public that must be filled by scientists providing facts, and facts alone. Although primarily targeting science-communication practitioners and academics researching the field, the Handbook can also help scientists to reflect on their outreach efforts and to appreciate the interplay between science and society.

Before plunging into the depths of the book, it is important to remember that the study of science communication is the study of evolving terminology. Historically, an effort was made to determine the “scientific literacy” of society, under the assumption that a society knowledgeable in the facts and methods of science would support research endeavours without much opposition. This approach was made obsolete by the introduction of the “public communication of science and technology” paradigm, which itself was superseded by what is today called “public engagement with science and technology”, or “public engagement” for short. The first chapter, written by the editors, is the best place to familiarise oneself with the various science-communication models, as well as the terms and phrases used throughout the Handbook. That said, those with backgrounds in natural sciences might feel somewhat out of their depth, due to a lack of definitions in the rest of the Handbook for words and phrases used on a daily basis by their social-science counterparts. However, this is largely mitigated by each chapter containing a wealth of notes and references at the end, pointing readers in the direction of further reading.

The chapters themselves are stand-alone articles by experts in their respective topics, many written in engaging, conversational styles. They cover everything from policy and participants, to the handling of “hot-button” issues, to research and assessment methodology. Readers of the Courier may find the chapters on science journalism, on public relations in science, on the role of scientists as public experts and on risk management particularly illuminating.

What the same readers might find missing from the book is a specific treatment of fundamental research: the Handbook focuses on domains of science – such as climate change – that tend to have a direct or immediate impact on society. Scientists from other areas of research might therefore consider shoehorning (perhaps non-existing) societal impact into their science-communication efforts, rather than learning how to adapt the lessons learnt from fields such as climate science to their own work. It is therefore this reviewer’s desire that future editions of the Handbook address the science-communication challenges of more diverse areas of research, proposing ways in which scientists and practitioners can tackle them.

Overall, the Handbook gives readers valuable insight into science-communication research, and merits a place on the library shelves of every university and research institution.

By E C G Sudarshan and N Mukunda
World Scientific

More than 40 years since the appearance of the first edition, this book in now published in a revised version that is presented with the same passion and dedication as the original. The authors confess that they have always had an “affair of the heart” with classical dynamics, and this remains alive.

In the volume, classical dynamics is treated as a subject in its own right, as well as a research frontier. While presenting all of the essential principles, the authors demonstrate that a number of key results originally considered only in the context of quantum theory and particle physics have their foundations in classical dynamics.

Even if the text is based on what the authors define as “our understanding of quantum mechanics”, this new version builds on many suggestions coming from other physicists and continuous dialogue with students using the book as a reference.