Men of Physics: L. D. Landau, Volume 2: Thermodynamics, Plasma Physics and Quantum Mechanics is dedicated to L. D. Landau’s contributions in the fields of thermodynamics, plasma physics, and quantum mechanics. Landau’s theory of second-order phase transitions is discussed, along with his contributions to nuclear physics, astrophysics, cosmic ray physics, and quantum field theory. This volume is comprised of 15 chapters and begins with a discussion on Landau’s theory of second-order phase transitions, which includes his assumption that all thermodynamic functions would allow regular series expansions near the transition point. The following chapters focus on Landau’s papers on the transport equation for ionized systems and on plasma oscillations; his contributions to nuclear physics, cosmic ray physics, and astrophysics; his work in pure quantum mechanics; and his contributions to quantum field theory. The second section elaborates on the theory of phase transitions; the transport equation in the case of Coulomb interactions; the vibrations of the electronic plasma; and the statistical theory of nuclei. The origin of stellar energy is also examined, along with the multiple production of particles during collisions of fast particles and the extension of the uncertainty principle to relativistic quantum theory. A theory of energy transfer in collisions is also described. The final chapter considers the conservation laws for weak interactions. This book will be a useful resource for physicists and students interested in the work of L. D. Landau.