Coherence In Spectroscopy And Modern Physics

This volume contains the lectures and seminars presented at the NATO Advanced Study Institute on "Coherence in Spectroscopy and Modern Physics," the seventh course of the International School of Quantum Electronics, affiliated with the "Ettore Majorana" Centre for Scientific Culture, Erice, Sicily. The Institute was held at Villa LePianore (Lucca), Versilia, Italy, July 17-30, 1977. The International School of Quantum Electronics was started in 1970 with the aim of providing instruction for young researchers and advanced students already engaged in the area of quantum electronics or wishing to switch to this area from a different background. From the outset the School has been under the direction of Prof. F. T. Arecchi, then at the University of Pavia, now at the University of Florence, and Dr. D. Roess of Siemens, Munich. Each year the Directors choose a subject of particular interest, alternating fundamental topics with technological ones, and ask colleagues specifically competent in a given area to take the scientific responsibility for that course.

The Seventh Rochester Conference on Coherence and Quantum Optics was held on the campus of the University of Rochester during the four-day period June 7 - 10, 1996. More than 280 scientists from 33 countries participated. This book contains the Proceedings of the meeting. This Conference differed from the previous six in the series in having only a limited number of oral presentations, in order to avoid too many parallel sessions. Another new feature was the introduction of tutorial lectures. Most contributed papers were presented in poster sessions. The Conference was sponsored by the American Physical Society, by the Optical Society of America, by the International Union of Pure and Applied Physics and by the University of Rochester. We wish to express our appreciation to these organizations for their support and we especially extend our thanks to the International Union of Pure and Applied Physics for providing financial assistance to a number of speakers from Third World countries, to enable them to take part in the meeting.

The impact which has been made on spectroscopy by lasers, and by this route on major segments of physics and chemistry, has received ample documen tation in the past several years. Two principal themes emerge from examina tion of the numerous books and monographs now available on this subject: first, an increase in spectral resolution to levels previously undreamed of; and, second, the generation of nonlinear phenomena as a result of the intense radiation fields available from laser devices. There is one additional property of laser radiation which, although used extensively in experiments, does not appear to have been as thoroughly reviewed as the foregoing aspects. This is the spatial and temporal coherence of the radiation field produced by the laser, which makes possible the coherent excitation of molecular energy states. This feature is the subject of the present volume. While the use of coherence methods in spectroscopy has been paced by lasers, it is by no me ans restricted to this technology. In the second and fourth chapters, microwave sources are discussed as generators of coherent radiation fields and are used to probe both rotational energy levels and spin states of electronically excited molecules. The phenomena discussed in this book, such as nutation, free induction decay, radiative echoes, rapid pas sage, and so forth, are really the same in different regions of the spectrum, and themselves echo from one chapter to the next.

The Eighth Rochester Conference on Coherence and Quantum Optics was held on the campus of the University of Rochester during the period June 13-16,2001. This volume contains the proceedings of the meeting. The meeting was preceded by an affiliated conference, the International Conference on Quantum Information, with some overlapping sessions on June 13. The proceedings of the affiliated conference will be published separately by the Optical Society of America. A few papers that were presented in common plenary sessions of the two conferences will be published in both proceedings volumes. More than 268 scientists from 28 countries participated in the week long discussions and presentations. This Conference differed from the previous seven in the CQO series in several ways, the most important of which was the absence of Leonard Mandel. Professor Mandel died a few months before the conference. A special memorial symposium in his honor was held at the end of the conference. The presentations from that symposium are included in this proceedings volume. An innovation, that we believe made an important contribution to the conference, was the inclusion of a series of invited lectures chaired by CQO founder Emil Wolf, reviewing the history of the fields of coherence and quantum optics before about 1970. These were given by three prominent participants in the development of the field, C. Cohen-Tannoudji, 1. F. Clauser, and R. I. Glauber.

Remarkable developments in the spectroscopy field regarding ultrashort pulse generation have led to the possibility of producing light pulses ranging from 50 to5 fs and frequency tunable from the near infrared to the ultraviolet range. Such pulses enable us to follow the coupling of vibrational motion to the electronic transitions in molecules and

This book features the proceedings of the NATO Advanced Study Institute "Manipulating Quantum Coherence in Solid State Systems", held in Cluj-Napoca, Romania, August 2005, which presented a fundamental introduction to solid-state approaches to achieving quantum computation. This proceedings volume describes the properties of quantum coherence in semiconductor spin-based systems and the behavior of quantum coherence in superconducting systems.

I am most pleased and, in a way, I feel honored to write the Foreword for the book The Hanle Effect and Level-Crossing Spectroscopy, which covers such a very wide range of applications not only in the initial areas of atomic and molecular physics, but also in solid state physics, solar physics, laser physics, and gravitational metrology. To link these fields together in a coherent way has been the merit of the editors of the book, who attracted most distinguished authors for writing the chapters. In retrospect to Hanle's discovery of quantum mechanical coherence between two quantum states about 65 years ago, this book demonstrates the enormous impact and central importance the effect has had, and most vividly still has, on modern physics. On the other hand, the concept of quantum mechanical coherence, which is an outgrowth of the linear super position principle of quantum states, has been evident through a consider able number of experimental methods beyond the original Hanle effect; some of these methods were only recently discovered or applied and they have indeed revolutionized research fields such as atomic collision physics.