Quantum Phase Transitions

Sachdev, Subir
Subir Sachdev is Professor of Physics at Harvard University and holds a Distinguished Research Chair at the Perimeter Institute for Theoretical Physics. His research has focused on a variety of quantum materials and especially on their quantum phase transitions.

Describing the physical properties of quantum materials near critical points with long-range many-body quantum entanglement, this book introduces readers to the basic theory of quantum phases, their phase transitions and their observable properties. This second edition begins with a new section suitable for an introductory course on quantum phase transitions, assuming no prior knowledge of quantum field theory. It also contains several new chapters to cover important recent advances, such as the Fermi gas near unitarity, Dirac fermions, Fermi liquids and their phase transitions, quantum magnetism, and solvable models obtained from string theory. After introducing the basic theory, it moves on to a detailed description of the canonical quantum-critical phase diagram at non-zero temperatures. Finally, a variety of more complex models are explored. This book is ideal for graduate students and researchers in condensed matter physics and particle and string theory.

Updated second edition with several new chapters, for graduates and researchers in condensed matter physics and particle and string theory.

Part I. Introduction: 1. Basic concepts; 2. Overview; Part II. A First Course: 3. Classical phase transitions; 4. The renormalization group; 5. The quantum Ising model; 6. The quantum rotor model; 7. Correlations, susceptibilities, and the quantum critical point; 8. Broken symmetries; 9. Boson Hubbard model; Part III. Non-zero Temperatures: 10. The Ising chain in a transverse field; 11. Quantum rotor models: large-N limit; 12. The d = 1, O(N 3) rotor models; 13. The d = 2, O(N 3) rotor models; 14. Physics close to and above the upper-critical dimension; 15. Transport in d = 2; Part IV. Other Models: 16. Dilute Fermi and Bose gases; 17. Phase transitions of Dirac fermions; 18. Fermi liquids, and their phase transitions; 19. Heisenberg spins: ferromagnets and antiferromagnets; 20. Spin chains: bosonization; 21. Magnetic ordering transitions of disordered systems; 22. Quantum spin glasses; References; Index.