Molecular Beams in Physics and Chemistry Bretislav Friedrich · Horst Schmidt-Böcking Editors

Molecular Beams in Physics and Chemistry From Otto Stern’s Pioneering Exploits to Present-Day Feats Editors Bretislav Friedrich Horst Schmidt-Böcking Fritz-Haber-Institut der Institut für Kernphysik Max-Planck-Gesellschaft Universität Frankfurt Berlin, Germany Frankfurt am Main, Hessen, Germany

ISBN 978-3-030-63962-4 ISBN 978-3-030-63963-1 (eBook) https://doi.org/10.1007/978-3-030-63963-1

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This Springer imprint is published by the registered company Springer Nature Switzerland AG The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland Preface

In 1919, at the Physics Department of the University of Frankfurt, Otto Stern carried out the first quantitative experiment using molecular beams. With this experiment, aimed at measuring the velocity distribution of molecules in a gas, Stern launched the molecular beam method. Stern would be awarded the1943 Nobel Prize in Physics “for his contribution to the development of the molecular ray [beam] method and his discovery of the magnetic moment of the proton.” In his Nobel lecture, delivered in 1946, Stern extolled the virtues of molecular beams thus: “The most distinctive characteristic property of the molecular ray method is its simplicity and directness. It enables us to make measurements on isolated neutral atoms or molecules with macro- scopic tools. For this reason, it is especially valuable for testing and demonstrating directly fundamental assumptions of the theory.” On September 1–5, 2019, a symposium was held at Frankfurt to mark the centen- nial of Stern’s pioneering experiment and to show that many key areas of modern science, in particular of physics and chemistry, originated in the seminal molecular beam work of Otto Stern and his school. Of special significance was the Stern–Gerlach experiment, carried out at Frankfurt in 1920–1922, which introduced the key concept of sorting quantum states via space quantization of angular momentum. Among its descendants are the prototypes for nuclear magnetic resonance, optical pumping, the laser, and atomic clocks, as well as incisive discoveries such as the Lamb shift and the anomalous increment in the magnetic moment of the electron, which launched quantum electrodynamics. In the 1960s, the molecular beam technique made inroads into chemistry as well, by enabling the study of elementary chemical reactions as single binary collisions of chemically well-defined reagents. The ensuing study of chemical reaction dynamics has remained one of the chief preoccupations of chemical/molecular physics to date. In the 1990s, a renaissance began in atomic physics, nurtured by the development of techniques to cool and trap atoms. Based on a combination of molecular beams with laser cooling, these techniques enabled the realization of quantum degeneracy in atomic gases, launched condensed-matter physics with tunable interactions, as well as transforming metrology.

v vi Preface

At the Otto Stern Symposium, forty-eight talks and thirty-five posters were presented to an international audience of one hundred fourteen attendees. The symposium was chaired by Dudley Herschbach (Harvard University) and J. Peter Toen- nies (Max-Planck-Institut für Dynamik und Selsbstorganisation, Göttingen) and presented as the 702th Heraeus-Seminar. The Physics Department at Frankfurt has been recognized by the European Phys- ical Society (EPS) as an “EPS Historic Site.” A plaque marking the site was unveiled during the Otto Stern Symposium by the President of the EPS Petra Rudolf, the President of the University of Frankfurt Birgitta Wolff, and the President of the German Physical Society Dieter Meschede. It honors the work of Max Born, Otto Stern, Walther Gerlach, Elisabeth Bormann, and Alfred Landé performed in Frankfurt during the period 1919–1922. In order to make the content and insights of the Otto Stern Symposium more enduring and, at the same time, accessible to a larger audience, we invited the symposium speakers and others to contribute chapters to the present volume, which is being published both as a print book and online with open access. The volume consists of a total of twenty-seven contributions, the first two serving as a prelude to the following parts: I. Historical Perspectives; II. Foundations of Quantum Physics and Precision Measurements; III. Femto- and Atto-Science; IV. Cold and Controlled Molecules; V. Matter Waves; and VI. Exotic Beams. We trust this volume will help readers to keep abreast of current developments in molecular beam research as well as to appreciate the history and evolution of this powerful method and the knowledge it reveals. The symposium was funded by grants from the Wilhelm and Else Heraeus Founda- tion https://www.we-heraeus-stiftung.de/english/, the Deutsche Forschungsgemein- schaft https://www.dfg.de/, Vereinigung von Freunden und Förderern der Johann Wolfgang Goethe-Universität http://www.uni-frankfurt.de/34841010/ueber_vff and Stiftung zur Förderung der internationalen wissenschaftlichen Beziehungen der Johann Wolfgang Goethe-Universität https://www.uni-frankfurt.de/38294561, and the Community Fund of Frontiers Media https://www.frontiersin.org. We thank them all for their generous support. We also thank Roentdek GmbH, Kelkheim, for generously funding the boat trip on the Rhine that concluded the symposium as well as for contributing to the cost of the symposium dinner. We are also grateful to the Senckenberg-Stiftung and the Physikalischer Verein Frankfurt and their Presidents Volker Mosbrugger und Wolfgang Grünbein as well as to Professor Andreas Mulch of the Senckenberg-Stiftung for kindly making the facilities of the historic Arthur-Weinberg Haus (Alte Physik, from 1919) available for the symposium. We also thank their colleagues Dr. Tobias Schneck and Professor Bruno Deiss for their kind help. Our special thanks go to Dr. Sebastian Eckardt, Dr. Markus Schöffler, Dr. Christian Janke, and Marianne Frey as well as to others from the Institut für Kernphysik of the University of Frankfurt for ensuring a perfect execution of our organizational plans both during the sessions and the breaks. We also thank to Joachim Weinert and Sandra Schwab for the realization of the Historic Site plaque. Preface vii

Last but not least, we thank Dr. Angela Lahee, Executive Editor at Springer Nature, for her dedicated support of the project that resulted in this book.

Berlin, Germany Bretislav Friedrich Frankfurt am Main, Germany Horst Schmidt-Böcking Contents

1 An Homage to Otto Stern ...... 1 Dudley Herschbach 2 A Greeting from Hamburg to the Otto Stern Symposium ...... 23 Peter E. Toschek

Part I Historical Perspectives 3 MyUncleOttoStern ...... 27 Lieselotte K. Templeton 4 My Great Uncle ...... 31 Alan Templeton 5 Otto Stern’s Molecular Beam Method and Its Impact on Quantum Physics ...... 37 Bretislav Friedrich and Horst Schmidt-Böcking 6 Otto Stern—With Einstein in Prague and in Zürich ...... 89 Hanoch Gutfreund 7 Our Enduring Legacy from Otto Stern ...... 97 Daniel Kleppner 8 Walther Gerlach (1889–1979): Precision Physicist, Educator and Research Organizer, Historian of Science ...... 119 Josef Georg Huber, Horst Schmidt-Böcking, and Bretislav Friedrich 9 100 Years Molecular Beam Method Reproduction of Otto Stern’s Atomic Beam Velocity Measurement ...... 163 Axel Gruppe, Simon Cerny, Kurt Ernst Stiebing, Cedric George, Jakob Hoffmann, Maximilian Ilg, Nils Müller, Alienza Satar, Vincent Schobert, Leander Weimer, Markus Dworak, Stefan Engel, Gustav Rüschmann, Viorica Zimmer, Erich Zanger, and Horst Schmidt-Böcking

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10 Wilhelm Heinrich Heraeus—Doctoral Student at the University Frankfurt ...... 187 S. Jorda and H. Schmidt-Böcking

Part II Foundations of Quantum Physics and Precision Measurements 11 Quantum or Classical Perception of Atomic Motion ...... 195 John S. Briggs 12 The Precision Limits in a Single-Event Quantum Measurement of Electron Momentum and Position ...... 223 H. Schmidt-Böcking, S. Eckart, H. J. Lüdde, G. Gruber, and T. Jahnke 13 Precision Physics in Penning Traps Using the Continuous Stern-Gerlach Effect ...... 247 Klaus Blaum and Günter Werth 14 Stern-Gerlach Interferometry with the Atom Chip ...... 263 Mark Keil, Shimon Machluf, Yair Margalit, Zhifan Zhou, Omer Amit, Or Dobkowski, Yonathan Japha, Samuel Moukouri, Daniel Rohrlich, Zina Binstock, Yaniv Bar-Haim, Menachem Givon, David Groswasser, Yigal Meir, and Ron Folman 15 Testing Fundamental Physics by Using Levitated Mechanical Systems ...... 303 Hendrik Ulbricht

Part III Femto- and Atto-Science 16 Inducing Enantiosensitive Permanent Multipoles in Isotropic Samples with Two-Color Fields ...... 335 Andres F. Ordonez and Olga Smirnova 17 Ultra-fast Dynamics in Quantum Systems Revealed by Particle Motion as Clock ...... 353 M. S. Schöfﬂer, L. Ph. H. Schmidt, S. Eckart, R. Dörner, A. Czasch, O. Jagutzki, T. Jahnke, J. Ullrich, R. Moshammer, R. Schuch, and H. Schmidt-Böcking 18 High-Resolution Momentum Imaging—From Stern’s Molecular Beam Method to the COLTRIMS Reaction Microscope ...... 375 T. Jahnke, V. Mergel, O. Jagutzki, A. Czasch, K. Ullmann, R. Ali, V. Frohne, T. Weber, L. P. Schmidt, S. Eckart, M. Schöfﬂer, S. Schößler, S. Voss, A. Landers, D. Fischer, M. Schulz, A. Dorn, L. Spielberger, R. Moshammer, R. Olson, M. Prior, R. Dörner, J. Ullrich, C. L. Cocke, and H. Schmidt-Böcking Contents xi

Part IV Cold and Controlled Molecules 19 STIRAP: A Historical Perspective and Some News ...... 445 Klaas Bergmann 20 Manipulation and Control of Molecular Beams: The Development of the Stark-Decelerator ...... 463 Gerard Meijer 21 Quantum Effects in Cold and Controlled Molecular Dynamics .... 477 Christiane P. Koch 22 From Hot Beams to Trapped Ultracold Molecules: Motivations, Methods and Future Directions ...... 491 N. J. Fitch and M. R. Tarbutt

Part V Matter Waves 23 Otto Stern and Wave-Particle Duality ...... 519 J. Peter Toennies 24 Otto Stern’s Legacy in Quantum Optics: Matter Waves and Deﬂectometry ...... 547 Stefan Gerlich, Yaakov Y. Fein, Armin Shayeghi, Valentin Köhler, Marcel Mayor, and Markus Arndt 25 Grating Diffraction of Molecular Beams: Present Day Implementations of Otto Stern’s Concept ...... 575 Wieland Schöllkopf

Part VI Exotic Beams 26 Liquid Micro Jet Studies of the Vacuum Surface of Water and of Chemical Solutions by Molecular Beams and by Soft X-Ray Photoelectron Spectroscopy ...... 597 Manfred Faubel 27 When Liquid Rays Become Gas Rays: Can Evaporation Ever Be Non-Maxwellian? ...... 631 Gilbert M. Nathanson