Quantised Vortices

Vortices comprising swirling motion of matter are observable in classical systems at all scales ranging from atomic size to the scale of galaxies. In quantum mechanical systems, such vortices are robust entities whose behaviours are governed by the strict rules of topology. The physics of quantum vortices is pivotal to basic science of quantum turbulence and high temperature superconductors, and underpins emerging quantum technologies including topological quantum computation. This handbook is aimed at providing a dictionary style portal to the fascinating quantum world of vortices.

This book draws together all the basic principles of vortex dynamics in neutral superfluids in one comprehensive volume.

This book discusses the properties of quantized vortex lines in superfluid helium-4 in the light of research on vortices in modern fluid mechanics, and gives the first comprehensive treatment of the problem. The author's comprehensive approach will make this book invaluable for students taking advanced undergraduate or graduate courses, and for all those involved in research on classical and quantum vortices.

This book springs from the programme Quantized Vortex Dynamics and Sup- ?uid Turbulence held at the Isaac Newton Institute for Mathematical Sciences (University of Cambridge) in August 2000. What motivated the programme was the recognition that two recent developments have moved the study of qu- tized vorticity, traditionally carried out within the low-temperature physics and condensed-matter physics communities, into a new era. The ?rst development is the increasing contact with classical ?uid dynamics and its ideas and methods. For example, some current experiments with - lium II now deal with very classical issues, such as the measurement of velocity spectra and turbulence decay rates. The evidence from these experiments and many others is that super?uid turbulence and classical turbulence share many features. The challenge is now to explain these similarities and explore the time scales and length scales over which they hold true. The observed classical aspects have also attracted attention to the role played by the ?ow of the normal ?uid, which was somewhat neglected in the past because of the lack of direct ?ow visualization. Increased computing power is also making it possible to study the coupled motion of super?uid vortices and normal ?uids. Another contact with classical physics arises through the interest in the study of super?uid vortex - connections. Reconnections have been studied for some time in the contexts of classical ?uid dynamics and magneto-hydrodynamics (MHD), and it is useful to learn from the experience acquired in other ?elds.

Progress in Low Temperature Physics: Quantum Turbulence presents seven review articles on the recent developments on quantum turbulence. Turbulence has been a great mystery in natural science and technology for more than 500 years since the time of Leonardo da Vinci. Recently turbulence in quantum systems at low temperatures has developed into a new research field. Quantum turbulence is comprised of quantized vortices, realized in superfluid helium and quantum gases of cold atoms. Some of the important topics include energy spectra, vibrating structures, and visualization techniques. The understanding of these remarkable systems can have an impact on the general field of turbulence and will be of broad interest to scientists and students in low temperature physics, hydrodynamics and engineering. Key subjects covered: Energy spectra in quantum turbulence, Turbulent dynamics in rotating helium superfluids: a comparison of 3He-B and 4He-II, Quantum turbulence in superfluid 3He at very low temperatures, The use of vibrating structures in the study of quantum turbulence, Visualization of quantum turbulence, Capillary turbulence on the surface of quantum fluids, Quantized vortices in atomic Bose-Einstein condensates Crucial information for all experimenters in low temperature physics

Recent investigations have highlighted the similarities between turbulence in cryogenic fluids at temperatures close to absolute zero, in particular superfluid helium, and turbulence in ordinary fluids. This book contains lectures on various theoretical and experimental aspects of the problem given by experts at the advanced school “Vortices and Turbulence at Low Temperatures” held at CISM, Udine, in the summer of 2007. The lectures provide an introduction into this rapidly expanding area of research. The book is suitable to PhD students and young researchers starting their career as well as established researchers in either low temperature physics or fluid mechanics who are interested in this problem.

In this thesis, the author develops numerical techniques for tracking and characterising the convoluted nodal lines in three-dimensional space, analysing their geometry on the small scale, as well as their global fractality and topological complexity---including knotting---on the large scale. The work is highly visual, and illustrated with many beautiful diagrams revealing this unanticipated aspect of the physics of waves. Linear superpositions of waves create interference patterns, which means in some places they strengthen one another, while in others they completely cancel each other out. This latter phenomenon occurs on 'vortex lines' in three dimensions. In general wave superpositions modelling e.g. chaotic cavity modes, these vortex lines form dense tangles that have never been visualised on the large scale before, and cannot be analysed mathematically by any known techniques.

Distinguished work by two noted authorities covers static structure and thermodynamics, calculation of liquid structure from a law of force, binary fluids, charged fluids, much more. 1976 edition.