Modern Physics for Scientists and Engineers International Edition, 4th Edition http://optics.hanyang.ac.kr/~shsong 1. THE BIRTH OF MODERN PHYSICS 2. SPECIAL THEORY OF RELATIVITY 3. THE EXPERIMENTAL BASIS OF QUANTUM PHYSICS 4. STRUCTURE OF THE ATOM 5. WAVE PROPERTIES OF MATTER AND QUANTUM MECHANICS I 6. QUANTUM MECHANICS II 7. THE HYDROGEN ATOM 8. ATOMIC PHYSICS 9. STATISTICAL PHYSICS 10. MOLECULES, LASERS, AND SOLIDS 11. SEMICONDUCTOR THEORY AND DEVICES 12. THE ATOMIC NUCLEUS 13. NUCLEAR INTERACTIONS AND APPLICATIONS 14. PARTICLE PHYSICS 15. GENERAL RELATIVITY 16. COSMOLOGY AND MODERN ASTROPHYSICS
8. ATOMIC PHYSICS What would happen if there are more than one electron? 8.1 Atomic Structure and the Periodic Table 8.2 Total Angular Momentum 8.3 Anomalous Zeeman Effect Pauli exclusion principle: No two electrons in an atom may have the same set of quantum numbers (n, l, m l, m s ). Periodic table can be understood by two rules: 1) The electrons in an atom tend to occupy the lowest energy levels available to them. 2) Only one electron can be in a state with a given (complete) set of quantum numbers (Pauli exclusion principle). Total angular momentum = Orbital angular momentum + Spin angular momentum L L1 L2 LS coupling: (for most atoms) J L S S S S 1 2 jj coupling: (for heavier atoms) J1 L1 S1 J J1 J2 J L S 2 2 2 Notation for a single-electron atom: 2S 1 n L J 1 3 3 3 P0,3 P2,3 D1 5 P, P, P 3 3 3 0,1,2 0,1,2 Anomalous Zeeman effect: More than 3 closely spaced optical lines m ( J,,0, J) J
9. Statistical Physics 9.1 Historical Overview 9.2 Maxwell Velocity Distribution 9.3 Equipartition Theorem 9.4 Maxwell Speed Distribution 9.5 Classical and Quantum Statistics 9.6 Fermi-Dirac Statistics 9.7 Bose-Einstein Statistics Statistics and Probability What are the relative probabilities of finding an atom in any particular state? Maxwell Velocity Distribution: What is the distribution of velocities for an ideal gas at a given T? 3 1 f ( ) d Cexp m 2 / kt d 3 2 1 Equipartition Theorem: Mean energy of kt 2 is associated with each degree of freedom For a single atom: DOF = 3 K kt 3 kt 1 3 2 2 For rigid connector: DOF = 5 (3-translational; 2-rotational) For spring connector: DOF = 7 (3-tran; 2-rot; 2-vibrational)
9. Statistical Physics 9.4 Maxwell Speed Distribution 9.5 Classical and Quantum Statistics 9.6 Fermi-Dirac Statistics 9.7 Bose-Einstein Statistics Maxwell Speed Distribution: the probability of finding a particle with speed between v ~ v+dv 1 2 2 f ( ) d 4 Cexp 2 m / kt d Most probable speed: Mean speed: Root-mean-square (rms) speed: * rms 2 kt / m * ( 4/ ) * * ( 3/2) rms Classical and Quantum Statistics: Classical Distributions Each particle is distinguishable There is no restriction on particle energies. Maxwell-Boltzman Quantum Distributions Each particle is indistinguishable due to overlap of wave functions There are only certain energy values allowed. Fermi-Dirac: identical/indistinguishable particles with integer spin (Fermions) Bose-Einstein: identical/indistinguishable particles with half-integer spin (Bosons)
10. Molecules and Solids What happens when atoms join together? 10.1 Molecular Bonding and Spectra 10.2 Stimulated Emission and Lasers 10.3 Structural Properties of Solids 10.4 Thermal and Magnetic Properties of Solids 10.5 Superconductivity 10.6 Applications of Superconductivity Molecular Bonding: binding energy (potential) Ionic bond Covalent bond Van der Waals bond Hydrogen bond Metallic bond Molecular Spectra: Band spectrum due to rotational and vibrational energy states
10. Molecules and Solids 10.2 Stimulated Emission and Lasers 10.3 Structural Properties of Solids 10.4 Thermal and Magnetic Properties of Solids 10.5 Superconductivity 10.6 Applications of Superconductivity Emission of Photons by molecules: Spontaneous and Stimulated Spontaneous Emission: emit a photon without any stimulus from the outside Stimulated Emission: emit a photon stimulated by incoming photons Maser: Microwave Amplification by the Stimulated Emission of Radiation (C. Townes, 1954) Laser: Light amplification by the Stimulated Emission of Radiation (T. Maiman, 1960)
10. Molecules and Solids 10.3 Structural Properties of Solids 10.4 Thermal and Magnetic Properties of Solids 10.5 Superconductivity 10.6 Applications of Superconductivity Condensed Matter Physics: Study of electronic properties of Solids and Liquids Crystal structure: The atoms are arranged in extremely regular, periodic patterns. Lattice = Set of points in space occupied by atomic centers Thermal expansion: Tendency of a solid to expand as its temperature increases Nearly linear with temperature in classical limit. Thermal Conductivity: A measure of how well they transmit thermal energy The ratio of thermal con. And electrical con. is proportional to T Magnetic properties: Characterized by intrinsic magnetic moments (Magnetic susceptivility: ) and their responses to applied magnetic fields (Magnetization: M) Diamagnetism, Paramagnetism, Ferromagnetism
10. Molecules and Solids 10.5 Superconductivity 10.6 Applications of Superconductivity Superconductivity: Absence of electrical resistance (Zero resistivity under critical T c ) Complete expulsion of magnetic flux (Meissner effect) BCS (J. Bardeen, L. Cooper, R. Schrieffer) Theory: Electron-Phonon interaction Cooper Pair (two-electron pair) + Lattice Phonon (lattice vibration) Applications: Josephson junctions: Superconductor-Insulator-Superconductor SQUIDs Maglev: Magnetic levitation of trains MRI: (Nuclear) Magnetic Resonance Imaging
11. Semiconductors How energy bands and forbidden energy gaps formed? 11.1 Band Theory of Solids 11.2 Semiconductor Theory 11.3 Semiconductor Devices 11.4 Nanotechnology Solids: Insulator, Metal, Semimetal, Semiconductor Band Theory: Conduction, Valence, Forbidden gap Kronig-Penney Model Semiconductor Theory: Distribution of electrons (fermions) at the various energy levels is governed by the Fermi-Dirac distribution Holes: vacancy in valence band (work as positive charge) n-type and p-type: adding only a small amount of dopants to silicon greatly increases the electrical conductivity. Semiconductor Devices: pn-junction Diodes: p-type and n-type semiconductors are joined together. Light-emitting diodes (LED), Photovotaic Cells (Solar cells) Transistors: npn-junction, pnp junction Field effect transistors (FET) Schottky barriers: Metal-semiconductor junction Nanotechnology: Scientific study and manufacture of materials on a submicron scale. Carbon Nanotubes, Graphene, Quantum Dots