A History of Engineering and Science in the Bell System Physical Sciences (1925-1980) Prepared by Members of the Technical Staff, AT&T Bell Laboratories. S. Millman, Editor. AT&T Bell Laboratories Credits for figm·es taken from other than Bell System sources appear on page 641. Copyright c 1983 Bell Telephone Laboratories, Incorporated All rights r•eserved f-1( e ; '/C, 1-' l / 'i ·~­ ''' First Printing, 1983 International Standard Book Number: 0-932764-03-7 Library of Congress Catalog Card Number: 83-62738 Printed in the United States of America Contents Foreword xiii Acknowledgments xxiii Part I. Research in Physics Overview .. 1 1. Magnetism and Magnetic Resonance . 19 I. The Physics of Magnetic Solids, 19. Ferromagnetic Metals and Alloys, 20. Ferromagnetic Domains, 22. Magnetic Oxides­ Ferrimagnetic Garnets, 26. Magnetic Moments and Interatomic Magnetic Interactions, 31. II. Magnetic Resonance and Solid State Spectroscopy-The Gyrator and Paramagnetic Amplifier, 35. Nuclear Magnetic Resonance, 36. Electron Paramagnetic Resonance, 39. Ferromagnetic Resonance, 46. Electron Orbital Resonance, 50. Resonance Experiments in the Far-Infrared, 52. III. Mossbauer Spectroscopy, 53. Hyperfine Structure Studies in Magnetic Materials, 53. Layer-Structure Compounds, 57. Amorphous Materials, 58. Studies of Electroplating, 58. References, 60. 2. Semiconductor Physics and Electronics- The Transistor . 71 I. Semiconductor Research up to 1948-The Point-Contact Transistor, 72. II. The Junction Transistor and Other Semiconductor Amplifiers, 74. The p-n Junction, 74. p-n Junction Transistors, 74. Field Effect Transistors, 76. The Read Diode, 78. Acoustic-Wave Amplifiers, 79. III. The Bell Solar Photovoltaic Cell, 79. IV. Transport Properties, 80. Phonon Drag and Thermal Transport, 81. V. Semiconductor Spectroscopy, 83. Band Structure in Semiconductors, 83. Pair Spectra, 87. Light Emitting Diodes, 89. Thin Layers, 90. Deep Levels, 91. Electron-Hole Liquids, 92. VI. Molecular Beam Epitaxy, 93. VII. Semiconductor Research Supplement-The Story of the "Genesis of the Transistor," 96. "The Genesis of the Transistor," 97. J. B. Fisk's Letter to Ralph Bown, 101. Walter H. Brattain's Personal Reminiscences, Recorded by Brattain in 1975, 101. References, 102. v vi Engineering and Science in the Bell System 3. Surface Physics- Wave Nature of the Electron . 109 I. The Davisson-Germer Experiment, 109. Quotations from Davisson's Nobel Lecture, December 13, 1937, 111. Davisson's "Well-Known Accident," 112. Quotations from Karl K. Darrow's "The Scientific Work of C. J. Davisson," 112. Observation of Spin Polarization Effe·cts, 113. II. Electron Emission from Solids, 114. Primary Emission, 114. Secondary Emission, 115. Au~;er Electron Emission Spectroscopy of Solids, 115. Field Emission, 116. III. Semiconductor Surface Research During 1948-1960, 119. Surface Charge, Contact Potential, and Surface Voltage, 119. Surface Photovoltage and Surface State·s, 120. Semiconductors in an Electrolyltic Ambient, 122. IV. Modern Surface Research- Controlled Surface int Ultra-High Vacuum, 122. Surface Crystallography-Low Energy JBlectron Diffraction, 124. Surface Electronic Structure, 125. MultiJPl•e Experiments in One Apparatus, 131. References, 133. 4. Electronic Band Structu:rE~ of Metals ...... 139 I. Fermi Surfaces, 139. II. Cyclotron Resonance, 141. Ill. Hi~;h-Field Galvanomagnetic Effects, 143. IV. The Oscillatory Effects, 145. deHaas-vanAlphen Effect, 145:. Magnetothermal Effect, 146. Magnetoacoustic Effects, 147. V. Band Structure Calculations, 147. References, 147. 5. Quantum Electronics-The Laser ............ 151 I. Microwave Spectroscopy andl Masers, 151. II. Physical Priinciples and Conditions for Laser Actio1n ·-The He-Ne Laser, 152. Earlly Solid State Lasers, 156. Modes of Oscillation in the Laser Resonating System, 158. Mode Locking and Pulse Generation, 161. Temporal Coherence of Laser Radiation, 163. III. La:sers for Optical Communication, 164. The Heterojunction Semiconductor Laser, 165. HeterostructurE! Lasers and Optical Fibers, 167. IV. Latiiers for Industrial Applic:ation!O- The 168. Yttrium Aluminum Garnet (YAG) Laser, 172. V. C02 Laser, Other Laser Types, 172. Lasers Based on Atomic Transitions, 172. Lasers Involving Vibrational-:Rotational Molecular Transitions, 173. Optically Pumped Molecular Ga:s l.asers, 174. Dye Lasers, 174. Color­ Center Lasers, 175. VI. Laserli in Physical Research, 176. High­ Resolution Spectroscopy, 176. R~tman and Brillouin Scattering, 178. Coherent Optical Effects, 181. Radiation Pressure and Optical Levitation, 184. VII. Nonlim~a1r Optics, 185. Second Hatrmonic Generation, 186. Optical Parametric Amplification, 192. Stimulated Raman Scattering and Lasers, 19':1,. References, 196. Contents vii 6. Atoms, Molecules, and Plasmas ............ 211 I. Atomic and Molecular Physics, 211. Lamb Shift in Hydrogenic Ions, 211. The Hydrogen Molecular Ion Hyperfine Structure, 212. Optical Pumping of States with Nonzero Orbital Angular Momentum, 213. Radiation from Low-Energy, Ion-Atom, and Ion-Molecule Collisions, 215. Anticrossing Spectroscopy, 215. Laser Spectroscopy, 218. Opto­ Acoustic Spectroscopy of Gases and Pollution Detection, 221. II. Plasma Physics, 223. Gas Discharges and the Arc Plasma, 224. The Collective Modes of Plasmas, 230. Plasma Instabilities, 237. Highly Nonlinear Plasma States, 242. III. Molecular Biophysics, 246. Nuclear Magnetic Relaxation of Water Protons in DNA, 247. Optical Studies of DNA and Other Molecules, 247. Physical Transport of Biomolecules, 249. Nuclear Magnetic Resonance, 249. Paramagnetic Resonance in Metalloenzymes, 251. Translation of the Genetic Code, 252. Extended X-Ray Absorption Spectroscopy in Biomolecules, 253. Fluorometric Screening Test for Lead Poisoning, 254. References, 258. 7. Astrophysics and Magnetospheric Physics- Cosmic Background Radiation . 269 I. Astrophysics, 269. Radio Astronomy-Early Observation of Galactic Radio Noise, 270. Microwave Background Noise Studies-Impact on Cosmology, 271. Application of Sensitive Receivers to the Study of Molecules in Interstellar Space, 274. Statistical Study of Galaxies, 276. Gravity Waves, 277. Gamma-Ray Line Astronomy, 277. The Indium Solar Neutrino Spectrometer, 278. II. The Magnetosphere, 279. Study of Electrons and Protons in the Van Allen Belts with Detectors in the Telstar Satellite, 279. Outer Zone Studies with Synchronous Altitude Satellites, 280. Effect of Solar Flares on Particles in Interplanetary Space, 281. Ground-Based Magnetometers in Antarctica and at High Northern Latitudes, 282. References, 284. 8. Ion Beams, X-Rays, Electrons, and Neutrons in Solids-Channeling and Ion Implantation ... 289 I. Particle Detectors, Nuclear Physics, and Ion Beam Research, 289. Semiconductor Particle Detectors, 290. The Rutgers University-Bell Laboratories Accelerator Laboratory, 294. Particle Channeling, 298. Ion Implantation, 305. Ion Scattering, 310. Sputtering, 314. II. X-Ray Scattering and Spectroscopy, 317. X-Ray Diffraction, 317. Inelastic X­ Ray Spectroscopy, 319. Extended X-Ray Absorption Fine Structure Spectroscopy, 325. III. X-Ray Photoelectron Spectroscopy, 328. Ionic and Covalent Bonding, 328. Core Electron and Conduction Electron Spectroscopy, 329. Rare Earth Ion Spectroscopy. 330. Application to viii En~ri111eering and Science in the BeU System Surface Studies, 330. IV. Neutr•3n. Scattering, 331. Phase Transition in Magnetic Systems, 333. Electronk Structure of Magnetic Systems, 334. References, 335. 9. Ordered Phases of Matte1r and Phase Transitions . • • . 0 .347 I. Superconductivity-Superc(Jinductive Tunneling, 347. Contri­ butions to Fundamental The011y,. 348. Quantized Flux Lin•es, 349. Strong Coupling Theory, 349. The Proximity Effect, 351. The Josephson Effect and Tunnel Ju.ndions, 351. II. Ferroelectricity, 354. BaTi03 Experiments, 355. Ferroelectric Domains in Triglycine Sulfate and Guanidine Aluminum Sulfate Hexahydrate, 357. Lattice Dynamics and Ferroelectricity, 358. III. Liquid Crystals, 359. The Nematic Phase, 359. The Smectic Phase, 359. The Cholesteric Phase, 360. Liquid Crystal Display Devices, 361. IV. Physics at Low Temperatures, 361. Vortex Rings in Superfluid Helium, 363. Phonons in Helium, 364. Surface Electrons on Sup•er:fluid Helium, 364. Superfluiidity in 3He, 367. V. Physics at High :Pressures, 370. Phase Diagrams in Electronic Transitions, 370. Metal-Insulator Transitions, 371. Transitions in Mixed-Valence Compounds, 372. VI. Phase Transitions and Critical Phenomena, 372. Calorimetric Investigations, 373. The Effect of Dimensionality of Space, 373. Critical Dynamic:s, 374. Structural Transitions, 374. Impad on Other Fields, 376. Reft~rences, 377. 10. The Role of Theoretical P'hysics at Bell Laboratories . .. .. .. 387 I. Nature of Theoretical Physi.cs, 387. II. The Buildup of the Theoretical Physics Effort, 389. Il[I. The Increasing Role of Quantum Mechanics-Physics of Ordered States, 390. IV. Extension to Localized States and Random Systems, 392. V. Many-Body Theory-­ Broken Symmetry and Superconductivity, 395. VI. Statistical Mechanics and Phase Transitions, 397. VII. Concluding Contmenbl, 398. References, 398. Part II. Resear•ch in Materials Overview . • . 40~l 11. Semiconductors-Silicon, Germanium, and III-V Compounds .••.................. 411 I. Compound Semiconductors for Thermistors and Varistor's, 411.. Thermistors, 412. Varistors, 413. II. Silicon and Germanium in Contents ix Point-Contact Rectifiers, 414. Silicon Rectifiers, 415. Germanium Rectifiers, 416. III. Silicon and Germanium Studies