Topological defects formed at symmetry-breaking phase transitions play an important role in many different fields of physics. They appear in many condensed-matter systems at low temperature; examples include vortices in superfluid helium-4, a rich variety of defects in helium-3, quantized mag netic flux tubes in type-II superconductors, and disclination lines and other defects in liquid crystals. In cosmology, unified gauge theories of particle interactions suggest a sequence of phase transitions in the very early uni verse some of which may lead to defect formation. In astrophysics, defects play an important role in the dynamics of neutron stars. In 1997 the European Science Foundation started the scientific network "Topological defects" headed by Tom Kibble. This network has provided us with a unique opportunity of establishing a collaboration between the representatives of these very different branches of modern physics. The NATO-ASI (Advanced Study Institute), held in Les Houches in February 1999 thanks to the support of the Scientific Division of NATO, the European Science Foundation and the CNRS, represents a key event of this ESF network. It brought together participants from widely different fields, with diverse expertise and vocabulary, fostering the exchange of ideas. The lectures given by particle physicists, cosmologists and condensed matter physicists are the result of the fruitful collaborations established since 1997 between groups in several European countries and in the U.S.A.

Topological defects formed at symmetry-breaking phase transitions play an important role in many different fields of physics. They appear in many condensed-matter systems at low temperature; examples include vortices in superfluid helium-4, a rich variety of defects in helium-3, quantized mag netic flux tubes in type-II superconductors, and disclination lines and other defects in liquid crystals. In cosmology, unified gauge theories of particle interactions suggest a sequence of phase transitions in the very early uni verse some of which may lead to defect formation. In astrophysics, defects play an important role in the dynamics of neutron stars. In 1997 the European Science Foundation started the scientific network "Topological defects" headed by Tom Kibble. This network has provided us with a unique opportunity of establishing a collaboration between the representatives of these very different branches of modern physics. The NATO-ASI (Advanced Study Institute), held in Les Houches in February 1999 thanks to the support of the Scientific Division of NATO, the European Science Foundation and the CNRS, represents a key event of this ESF network. It brought together participants from widely different fields, with diverse expertise and vocabulary, fostering the exchange of ideas. The lectures given by particle physicists, cosmologists and condensed matter physicists are the result of the fruitful collaborations established since 1997 between groups in several European countries and in the U.S.A.

This volume contains the papers presented at the NATO Advanced Research Institute on "Non-Linear Dynamics and Fundamental Interactions" held in Tashkent, Uzbekistan, from Oct.10-16,2004. The main objective of the Workshop was to bring together people working in areas of Fundamental physics relating to Quantum Field Theory, Finite Temperature Field theory and their applications to problems in particle physics, phase transitions and overlap regions with the areas of Quantum Chaos. The other important area is related to aspects of Non-Linear Dynamics which has been considered with the topic of chaology. The applications of such techniques are to mesoscopic systems, nanostructures, quantum information, particle physics and cosmology. All this forms a very rich area to review critically and then find aspects that still need careful consideration with possible new developments to find appropriate solutions. There were 29 one-hour talks and a total of seven half-hour talks, mostly by the students. In addition two round table discussions were organised to bring the important topics that still need careful consideration. One was devoted to questions and unsolved problems in Chaos, in particular Quantum Chaos. The other round table discussion considered the outstanding problems in Fundamental Interactions. There were extensive discussions during the two hours devoted to each area. Applications and development of new and diverse techniques was the real focus of these discussions. The conference was ably organised by the local committee consisting of D.U.

This thesis reports on outstanding work in two main subfields of quantum information science: one involves the quantum measurement problem, and the other concerns quantum simulation. The thesis proposes using a polarization-based displaced Sagnac-type interferometer to achieve partial collapse measurement and its reversal, and presents the first experimental verification of the nonlocality of the partial collapse measurement and its reversal. All of the experiments are carried out in the linear optical system, one of the earliest experimental systems to employ quantum communication and quantum information processing. The thesis argues that quantum measurement can yield quantum entanglement recovery, which is demonstrated by using the frequency freedom to simulate the environment. Based on the weak measurement theory, the author proposes that white light can be used to precisely estimate phase, and effectively demonstrates that the imaginary part of the weak value can be introduced by means of weak measurement evolution. Lastly, a nine-order polarization-based displaced Sagnac-type interferometer employing bulk optics is constructed to perform quantum simulation of the Landau-Zener evolution, and by tuning the system Hamiltonian, the first experiment to research the Kibble-Zurek mechanism in non-equilibrium kinetics processes is carried out in the linear optical system.

Tom Kibble is an inspirational theoretical physicist who has made profound contributions to our understanding of the physical world. To celebrate his 80th birthday a one-day symposium was held on March 13, 2013 at the Blackett Laboratory, Imperial College, London. This important volume is a compilation of papers based on the presentations that were given at the symposium. The symposium profiled various aspects of Tom's long scientific career. The tenor of the meeting was set in the first talk given by Neil Turok, director of the Perimeter Institute for Theoretical Physics, who described Tom as "our guru and example." He gave a modern overview of cosmological theories, including a discussion of Tom's pioneering work on how topological defects might have formed in the early universe during symmetry-breaking phase transitions. Wojciech Zurek of Los Alamos National Laboratory continued with this theme, surveying analogous processes within the context of condensed matter systems and explaining the Kibble Zurek scaling phenomenon. The day's events were concluded by Jim Virdee of Imperial College, who summarized the epic and successful quest of finding the Higgs boson at the Large Hadron Collider at CERN. At the end of the talk, there was a standing ovation for Tom that lasted several minutes. In the evening, Steven Weinberg gave a keynote presentation to a capacity audience of 700 people. He talked eruditely on symmetry breaking and its role in elementary particle physics. At the banquet dinner, Frank Close of Oxford University concluded the banquet speeches by summarizing the significance of Tom's contributions to the creation of the Standard Model.

In this book, the equilibrium and nonequilibrium properties of continuous phase transitions are studied in various systems, with a special emphasis on understanding how well-established universal traits at equilibrium may be extended into the dynamic realm, going beyond the paradigmatic Kibble–Zurek mechanism of defect formation. This book reports on the existence of a quantum phase transition in a system comprising just a single spin and a bosonic mode (the quantum Rabi model). Though critical phenomena are inherent to many-body physics, the author demonstrates that this small and ostensibly simple system allows us to explore the rich phenomenology of phase transitions, both in- and out-of-equilibrium. Moreover, the universal traits of this quantum phase transition may be realized in a single trapped-ion experiment, thus avoiding the need to scale up the number of constituents. In this system, the phase transition takes place in a suitable limit of system parameters rather than in the conventional thermodynamic limit – a novel notion that the author and his collaborators have dubbed the finite-component system phase transition. As such, the results gathered in this book will open promising new avenues in our understanding and exploration of quantum critical phenomena.

Tom Kibble is an inspirational theoretical physicist who has made profound contributions to our understanding of the physical world. To celebrate his 80th birthday a one-day symposium was held on March 13, 2013 at the Blackett Laboratory, Imperial College, London. This important volume is a compilation of papers based on the presentations that were given at the symposium.The symposium profiled various aspects of Tom's long scientific career. The tenor of the meeting was set in the first talk given by Neil Turok, director of the Perimeter Institute for Theoretical Physics, who described Tom as “our guru and example”. He gave a modern overview of cosmological theories, including a discussion of Tom's pioneering work on how topological defects might have formed in the early universe during symmetry-breaking phase transitions. Wojciech Zurek of Los Alamos National Laboratory continued with this theme, surveying analogous processes within the context of condensed matter systems and explaining the Kibble-Zurek scaling phenomenon. The day's events were concluded by Jim Virdee of Imperial College, who summarized the epic and successful quest of finding the Higgs boson at the Large Hadron Collider at CERN. At the end of the talk, there was a standing ovation for Tom that lasted several minutes.In the evening, Steven Weinberg gave a keynote presentation to a capacity audience of 700 people. He talked eruditely on symmetry breaking and its role in elementary particle physics. At the banquet dinner, Frank Close of Oxford University concluded the banquet speeches by summarizing the significance of Tom's contributions to the creation of the Standard Model.