This thesis presents the first ever measurement of the noise emitted by magnetic monopoles and the development of an exquisitely sensitive magnetic-field-noise spectrometer based on a superconducting quantum interference device (SQUID) that enabled it. Magnetic monopoles are highly elusive elementary particles exhibiting quantized magnetic charge. The prospects for studying them brightened recently with the theoretical discovery that the thermally excited states in certain classes of magnetic insulators exhibit all the characteristics of magnetic monopoles. Furthermore, in 2018, it was predicted that the random motion of magnetic monopoles inside would generate a very specific kind of magnetization noise. In this thesis, the author describes a new experimental technique, so-called spin noise spectroscopy, and the subsequent discovery of virtually all of the predicted features of the magnetic noise expected from a dense fluid of magnetic monopoles in crystals of Dy2Ti2O7. Remarkably, because this magnetic monopole noise occurs in the frequency range below 20kHz, when amplified by the SQUID it is actually audible to humans.

In 1269 Petrus Peregrinus observed lines of force around a lodestone and noted that they were concentrated at two points which he designated as the north and south poles of the magnet. Subsequent observation has confirmed that all magnetic objects have paired regions of' opposite polarity, that is, all magnets are dipoles. It is easy to conceive of an isolated pole, which J.J. Thomson did in 1904 when he set his famous problem of the motion of an electron in the field of a magnetic charge. In 1931 P.A.M. Dirac solved this problem quantum mechanically and showed that the existence of a single magnet pole anywhere in the universe could explain the mystery of charge quantization. By late 1981, theoretical interest in monopoles had reached the point where a meeting was organized at the International Centre for Theoretical Physics in Trieste. Many mathematical properties of monopoles were discussed at length but there was only a solitary account describing experiments. This imbalance did not so much reflect the meeting's venue as it indicated the relative theoretical and experimental effort at that point.

These lecture notes discusses the developments both in the theoretical understanding of the physics and mathematics of magnetic monopoles as well as the ways in which they can be detected experimentally.The subject has now become highly interdisciplinary and recent monopole meetings have attracted participants from low temperature physics at one extreme to cosmology at the other.

Ten years have passed since It Hooft and Polyakov demonstrat ed that superheavy magnetic monopoles were a natural consequence of any Grand Unified Theory (GUT) in which the unifying group contains a U(l) factor as a subgroup. An analysis of these GUTs in an expanding, cooling universe yields a phase transition at an energy ~l015 GeV and at a cosmic time ~lO-35 seconds after the big bang. The general consequences of GUTs and this phase transition are the prediction of proton decay, the production of superheavy magnetic monopoles, and an understanding of the observed excess of matter over anti-matter in the universe. Attempts to provide experimental verification of GUTs has led to valiant experimental efforts in recent years to observe nucleon decay in massive underground detectors. Experiments to search for superheavy monopoles may eventually require similar efforts. Since the unification scale is unreachable in the laboratory, monopole detectors must search for relics of the big bang. Much theoretical groundwork has been accomplished in recent years with the development of GUTs. In Part I of this book, Erick Weinberg gives a theoretical overview of the role of magnetic monopoles in the various unification schemes. Monopoles in the context of the newly revived Kaluza-Klein theories are presented by several authors and are summarized by Qaisar Shafi. Mike Turner begins Part II with a discussion of monopoles in standard big bang cosmology. Paul Steinhardt follows with his perspectives on the inflationary universe; C.

This workshop is a series of meetings organized by the Institute for Scientific Interchange in Torino, Italy. It focuses on the potential of Superconductivity in the field of radiation detection and is particularly timely and important. The proceedings of the workshop highlights research on Superconducting Detectors for Nuclear Physics, Particle Physics and Astrophysics, Superconducting Tunneling Junctions, Superheated Superconducting Granules among other topics.

Publisher description

An award-winning Oxford physicist draws on classic sci-fi, fantasy fiction, and everyday phenomena to explain and celebrate the magical properties of the world around us. If you were to present the feats of modern science to someone from the past, those feats would surely be considered magic. Theoretical physicist Felix Flicker proves that they are indeed magic—just familiar magic. The name for this magic is “condensed matter physics.” Most people haven’t heard of the field, yet more than a third of physicists identify as condensed matter researchers, making it the most active area in the subject—with good reason. Condensed matter is the solids, liquids, and gasses that surround us—and the more exotic matters—which dictate every aspect of our present existence and hold the keys to a brighter future, from quantum computing to real-life invisibility cloaks. Flicker teases out the magical threads that run through our daily lives. Condensed matter physics allows you to create anything abiding by the laws of reality—and often, we find that those laws can be bent. Flicker explains how to create new particles that never existed before, how to make crystals shoot out of such intense light they can cut through metal, how to separate the poles of a magnet, and more. The book’s endearing conceit is that you are an aspiring wizard whose ability to cast spells (i.e. to do science) is dependent on your grasp of the fundamentals of our universe. This book contains no equations or charts—instead, it’s full of owls and mountains and infinite libraries, and staffs and wands, and martial arts and mythical islands ruled by sage knot-makers. Part of the book’s magic is that, for all these fanciful trappings, it still feels practical and applicable. The Magick of Physics will open your eyes to magic that surround us everyday.

Principles and applications of SQUIDs serves as a textbook and a multi-author collection of critical reviews. Providing both basic aspects and recent progress in SQUIDs technology, it offers a realistic and stimulating picture of the state of the art. It can also contribute to a further development of the field for commercial applications.

Functional Magnetic Resonance Imaging (fMRI) has become a standard tool for mapping the working brain's activation patterns, both in health and in disease. It is an interdisciplinary field and crosses the borders of neuroscience, psychology, psychiatry, radiology, mathematics, physics and engineering. Developments in techniques, procedures and our understanding of this field are expanding rapidly. In this second edition of Introduction to Functional Magnetic Resonance Imaging, Richard Buxton – a leading authority on fMRI – provides an invaluable guide to how fMRI works, from introducing the basic ideas and principles to the underlying physics and physiology. He covers the relationship between fMRI and other imaging techniques and includes a guide to the statistical analysis of fMRI data. This book will be useful both to the experienced radiographer, and the clinician or researcher with no previous knowledge of the technology.

This book contains an interdisciplinary selection of timely articles which cover a wide range of superconducting technologies ranging from high tech medicine (10-12 Gauss) to multipurpose sensors, microwaves, radio engineering, magnet technology for accelerators, magnetic energy storage, and power transmission on the 109 watt scale. It is aimed primarily at the non-specialist and will be suitable as an introductory course book for those in the relevant fields and related industries. As shown in the title several examples of high-c applications are included. While low-Tc is still the leading technology, for instance, in cables and SQUIDS, case studies in these areas are presented.