Modern Physics for Scientists and Engineers. International Edition, 4th Edition. 1.
THE BIRTH OF MODERN PHYSICS. 2. SPECIAL THEORY OF RELATIVITY. 3.
Modern Physics for Scientists and Engineers International Edition, 4th Edition http://optics.hanyang.ac.kr/~shsong 1. 2. 3. 4. 5. 6. 7.
THE BIRTH OF MODERN PHYSICS SPECIAL THEORY OF RELATIVITY THE EXPERIMENTAL BASIS OF QUANTUM PHYSICS STRUCTURE OF THE ATOM WAVE PROPERTIES OF MATTER AND QUANTUM MECHANICS I QUANTUM MECHANICS II THE HYDROGEN ATOM
8. 9. 10. 11. 12. 13. 14. 15. 16.
ATOMIC PHYSICS STATISTICAL PHYSICS MOLECULES, LASERS, AND SOLIDS SEMICONDUCTOR THEORY AND DEVICES THE ATOMIC NUCLEUS NUCLEAR INTERACTIONS AND APPLICATIONS PARTICLE PHYSICS GENERAL RELATIVITY 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, mℓ, ms).
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 LS coupling: (for most atoms)
L L1 L2 S S1 S 2
J LS
jj coupling: (for heavier atoms)
J1 L1 S1 J 2 L2 S 2
J J1 J 2
Notation for a single-electron atom:
n 2 S 1 LJ
31P0 ,3 3 P2 ,3 3 D1
5 3 P0,1,2 , 3 P0,1,2 , 3 P
Anomalous Zeeman effect: More than 3 closely spaced optical lines mJ ( J , , 0, J )
9. Statistical Physics
Statistics and Probability What are the relative probabilities of finding an atom in any particular state?
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 Maxwell Velocity Distribution: What is the distribution of velocities for an ideal gas at a given T? f ( )d 3 C exp 12 m 2 / kT d 3
Equipartition Theorem: Mean energy of
1 2
kT is associated with each degree of freedom
For a single atom: DOF = 3 K 12 kT 3 23 kT 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 f ( )d 4 C exp 12 m 2 / kT 2 d
Most probable speed:
* 2kT / m
( 4 / ) * Root-mean-square (rms) speed: rms ( 3 / 2) * Mean speed:
* 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 10.2 10.3 10.4 10.5 10.6
Molecular Bonding and Spectra Stimulated Emission and Lasers Structural Properties of Solids Thermal and Magnetic Properties of Solids Superconductivity 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 10.3 10.4 10.5 10.6
Stimulated Emission and Lasers Structural Properties of Solids Thermal and Magnetic Properties of Solids Superconductivity 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 10.4 10.5 10.6
Structural Properties of Solids Thermal and Magnetic Properties of Solids Superconductivity 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 Tc ) 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 11.2 11.3 11.4
Band Theory of Solids Semiconductor Theory Semiconductor Devices 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
