tailieunhanh - Minds Machines and The Multiverse

Anything you can do in classical physics, we can do better quantum physics. I head that remark in Boulder, Colorado, a few years ago when Dan Kleppners, a distinguished MT quantum physicist, was giving a lec-ture to a group of scientists on the subject of the quantum chaos. | Minds Machines and the Multiverse The Quest for the Quantum Computer JULIAN BROWN SIMON SCHUSTER New York London Toronto Sydney Singapore Simon Schuster Rockefeller Center 1230 Avenue of the Americas New York NY 10020 Copyright 2000 by Julian Brown All rights reserved including the right of reproduction in whole or in partjin any form. Simon Schuster and colophon are registered trademarks of Simon Schuster Inc. Designed by Leslie Phillips Manufactured in the United States of America 13579 10 8642 j LIBRARY OF CONGRESS CATALOGING-IN-PUBLICATION DATA Brown J. R. Julian Russell 1957- Minds machines and the multiverse the quest for the quantum computer Julian Brown p. cm Includes bibliographical references and index. 1. Quantum computers. I. Title B76 2000 dc21 I 99-056638 ISBN 0-684-81481-1 I Acknowledgments Anything you can do in classical physics we can do better in quantum physics. I heard that remark in Boulder Colorado a few years ago when Dan Kleppner a distinguished MIT quantum physicist was giving a lecture to a group of scientists on the subject of quantum chaos. His comment struck me at the time as particularly apposite because I saw it as being in many ways a leitmotif for this book. Quantum physics appears to be a supreme overarching theory of the universe. Nuclear physics atomic spectroscopy chemistry electronics materials science the physics of stars and black holes and even the structure of the universe all depend crucially on the laws of quantum theory. Yet in our everyday lives most of US are normally only aware of the classical physics that Newton brought to the fore. That quantum physics is built upon strange unworldly behavior at the atomic level has been appreciated by scientists for much of the twentieth century. There have been hints that quantum physics can engender unusual states at the macroscopic level too Witness the phenomena of superconductivity and superfluidity. But for a profound theory such things would appear to be .