TY - BOOK TI - Statistical mechanics SN - 9789380931890 U1 - 530.13 PY - 2011/// CY - Amsterdam PB - Elsevier N1 - 1. The Statistical Basis of Thermodynamics 1 1.1. The macroscopic and the microscopic states 1 1.2. Contact between statistics and thermodynamics: physical significance of the number Q(N, V,E) 3 1.3. Further contact between statistics and thermodynamics 6 1.4. The classical ideal gas 9 1.5. The entropy of mixing and the Gibbs paradox 16 1.6. The "correct" enumeration of the microstates 20 Problems 22 2. Elements of Ensemble Theory 25 2.1. Phase space of a classical system 25 2.2. Liouville's theorem and its consequences 27 2.3. The microcanonical ensemble 30 2.4. Examples 32 2.5. Quantum states and the phase space 35 Problems 37 vi Contents 3. The Canonical Ensemble 39 3.1. Equilibrium between a system and a heat reservoir 40 3.2. A System in the canonical ensemble 41 3.3. Physical significance of the various statistical quantities in the canonical ensemble 50 3.4. Alternative expressions for the partition function 52 3.5. The classical systems 54 3.6. Energy Fluctuations in the canonical ensemble: correspondence with the microcanonical ensemble 58 3.7. TWo theorems —the "equipartition" and the "virial" 61 3.8. A System of harmonic oscillators 65 3.9. The statistics of paramagnetism 70 3.10. Thermodynamics of magnetic systems: negative temperatures 77 Problems q3 4. The Grand Canonical Ensemble 91 4.1. Equilibrium between system and a particle-energy reservoir gj 4.2. A System in the grand canonical ensemble 93 4.3. Physical significance of the various statistical quantities 95 4.4. Examples 9g 4.5. Density and energy fluctuations in the grand canonical ensemble: correspondence with other ensembles 103 4.6. Thermodynamic phase diagrams IO5 4.7. Phase equilibrium and the Clausius-Clapeyron equation 109 Problems 5. Formulation of Quantum Statistics 5.1. Quantum-mechanical ensemble theory: the density matrix 5.2. Statistics of the various ensembles 5.3. Examples 122 5.4. Systems composed of indistinguishable particles 128 5.5. The density matrix and the partition function of a system of free particles 133 Problems 139 6. The Theory of Simple Gases 141 6.1. An ideal gas in a quantum-mechanical microcanonical ensemble 141 6.2. An Ideal gas in other quantum-mechanical ensembles 146 6.3. Statistics of the occupation numbers 149 6.4. Kinetic considerations 152 6.5. Gaseous systems composed of molecules with internal motion 155 6.6. Chemical equilibrium 170 Problems 173 7. Ideal Bose Systems 179 7.1. Thermodynamic behavior of an ideal Bose gas i80 7.2. Bose-Einstein condensation in ultracold atomic gases 191 ^ 7.3. Thermodynamics of the blackbody radiation 200 7.4. The field of sound waves 205 7.5. Inertial density of the sound field 212 7.6. Elementary excitations in liquid helium II 215 Problems 223 8. Ideal Fermi Systems 231 8.1. Thermodynamic behavior of an ideal Fermi gas 231 8.2. Magnetic behavior of an ideal Fermi Gas 238 8.3. The electron gas in metals 247 8.4. Ultracold atomic Fermi gases 258 Contents vii viii Contents 8.5. Statistical equilibrium of white dwarf stars 259 8.6. Statistical model ofthe atom 264 Problems 269 9. Thermodynamics of the Early Universe 275 9.1. Observational evidence of the Big Bang 275 9.2. Evolution of the temperature of the universe 280 9.3. Relativistic electrons, positrons, and neutrinos 282 9.4. Neutron fraction 285 9.5. Annihilation of the positrons and electrons 287 9.6. Neutrino temperature 289 9.7. Primordial nucleosynthesis 290 9.8. Recombination 293 9.9. Epilogue 295 Problems 296 10. Statistical Mechanics of Interacting Systems: The Method of Cluster Expansions 299 10.1. Cluster expansion for a classical gas 299 10.2. Virial expansion of the equation of state 307 10.3. Evaluation of the virial coefficients 309 10.4. General remarks on cluster expansions 315 10.5. Exact treatment of the second virisd coefficient 320 10.6. Cluster expansion for a quantum-mechanical system 325 10.7. Correlations and scattering 331 Problems 340 11. Statistical Mechanics of Interacting Systems: The Method of Quantized Fields 345 11.1. The~formalism of second quantization 345 11.2. Low-temperature behavior of an imperfect Bose gas 355 11.3. Low-lying states of an imperfect Bose gas 361 11.4. Energy spectrum of a Bose liquid 366 11.5. States with quantized circulation 370 11.6. Quantized vortex rings and the breakdown of superfluidity 376 11.7. Low-lying states of an imperfect Fermi gas 379 11.8. Energy spectrum of a Fermi liquid: Landau phenomenological theory 385 11.9. Condensation in Fermi systems 392 Problems 394 12. Phase Transitions: Criticality, Universality, and Scaling 401 12.1. General remarks on the problem of condensation 402 12.2. Condensation ofa van der Waals gas 407 12.3. A Dynamical model of phase transitions 411 12.4. The lattice gas and the binary alloy 417 12.5. Ising model in the zeroth approximation 420 12.6. Ising model in the first approximation 427 12.7. The critical exponents 435 12.8. Thermodynamic inequalities 438 12.9. Landau's phenomenological theory 442 12.10. Scaling hypothesis for thermodynamic functions 446 12.11. The role of correlations £ind fluctuations 449 12.12. The critical exponents Vand 77 456 12.13. Afinal look at the mean field theory 460 Problems 463 13. Phase Transitions: Exact (or Almost Exact) Results for Various Models 471 13.1. One-dimensional fluid models 471 13.2. The Ising model in one dimension 476 Contents ix X Contents 13.3. The n-vector models in one dimension 482 13.4. The Ising model in two dimensions 488 13.5. The spherical model in arbitrary dimensions 508 13.6. The ideal Bose gas in arbitrary dimensions 519 13.7. Other models 526 Problems 530 14. Phase Transitions: The Renormalization Group Approach 539 14.1. The conceptual basis of scaling 540 14.2. Some simple examples of renormalization 543 14.3. The renormalization group: general formulation 552 14.4. Applications of the renormalization group 559 14.5. Finite-size scaling 570 Problems 15. Fluctuations and Nonequilibrium Statistical Mechanics 583 15.1. Equilibrium thermodynamic fluctuations 584 15.2. The Einstein-Smoluchowski theory of the Brownian motion 15.3. The Langevin theory of the Brownian motion 593 15.4. Approach to equilibrium: tiie Fokker-Planck equation 603 15.5. Spectral £analysis of fluctuations: the Wiener-Khintchine theorem 609 15.6. The fluctuation-dissipation theorem 617 15.7. The Onsager relations 626 Problems 632 16. Computer Simulations 637 16.1. Introduction and statistics 637 16.2. Monte Carlo simulations 640 16.3. Molecular dynamics 643 16.4. Particle simulations 646 16.5. Computer simulation caveats 650 ER -