Artículos con la etiqueta ‘What is the origin emergence and universality?’

Thermodynamical Phase transitions, the mean-field theories, and the renormalization (semi)group: A pedagogical introduction

Por • 1 mar, 2014 • Category: Leyes

Mean field theories are good qualitative descriptors of the phase transition behavior. But all mean-field theories (including Landau’s theory) fail at the critical point (the problem of large correlation length). The problems with large correlation length in quantum many-body systems are the hardest problems known in theoretical physics (both in condensed matter and in particle physics). It was Ken Wilson’s physical insights and his powerful mathematical skills that opened a way to the solution of such hard problems. This manuscript is a perspective on these issues. Starting with simple examples of phase transitions (like ice/water; diamond/graphite etc.) we address the following important questions: Why does non-analyticity (sharp phase transitions) arise when thermodynamical functions (i.e., free energies etc) are good analytic functions? How does Landau’s program unify all the previous mean-field theories? Why do all the mean-field theories fail near the critical point? How does Wilson’s program go beyond all the mean-field theories? What is the origin emergence and universality?