Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Physics

Missouri University of Science and Technology

2013

Phase transition

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Phases And Phase Transitions In Disordered Quantum Systems, Thomas Vojta Oct 2013

Phases And Phase Transitions In Disordered Quantum Systems, Thomas Vojta

Physics Faculty Research & Creative Works

These lecture notes give a pedagogical introduction to phase transitions in disordered quantum systems and to the exotic Griffiths phases induced in their vicinity. We first review some fundamental concepts in the physics of phase transitions. We then derive criteria governing under what conditions spatial disorder or randomness can change the properties of a phase transition. After introducing the strong-disorder renormalization group method, we discuss in detail some of the exotic phenomena arising at phase transitions in disordered quantum systems. These include infinite-randomness criticality, rare regions and quantum Griffiths singularities, as well as the smearing of phase transitions. We also …


Phase Transitions In Disordered Systems, Fawaz Y. Hrahsheh Jan 2013

Phase Transitions In Disordered Systems, Fawaz Y. Hrahsheh

Doctoral Dissertations

"Disorder can have a wide variety of consequences for the physics of phase transitions. Some transitions remain unchanged in the presence of disorder while others are completely destroyed. In this thesis we study the effects of disorder on several classical and quantum phase transitions in condensed matter systems. After a brief introduction, we study the ferromagnetic phase transition in a randomly layered Heisenberg magnet using large-scale Monte-Carlo simulations. Our results provide numerical evidence for the exotic infinite-randomness scenario. We study classical and quantum smeared phase transitions in substitutional alloys A₁₋ₓBₓ. Our results show that the disorder completely destroys the phase …