2014/01/31 by Hiroyuki Yamase
Mathematics · Physics and Astronomy · #Anisotropy #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Critical field #Critical point (mathematics) #Geometry #Instability #Liquid crystal #Mathematics #Phase (matter) #Phase diagram #Phase transition #Physics #Physics of Superconductivity and Magnetism #Quantum critical point #Quantum mechanics #Quantum phase transition #Superconductivity #Theoretical and Computational Physics #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.91.195121
published as Phys. Rev. B 91, 195121 (2015) · 19 pages, 2 figures
arxiv created 2014/09/29 · openalex publication_date 2015/05/13 · arxiv updated 2015/05/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study the phase diagram of electronic nematic instability in the presence of xy anisotropy. While a second-order transition cannot occur in this case, mean-field theory predicts that a first-order transition occurs near Van Hove filling and its phase boundary forms a wing structure, which we term a Griffiths wing, referring to his original work of He3\ensuremath-He4 mixtures. When crossing the wing, the anisotropy of the electronic system exhibits a discontinuous change, leading to a metanematic transition, i.e., the analog to a metamagnetic transition in a magnetic system. The upper edge of the wing corresponds to a critical end line. It shows a nonmonotonic temperature dependence as a function of the external anisotropy and vanishes at a quantum critical end point for a strong anisotropy. The mean-field phase diagram is found to be very sensitive to fluctuations of the nematic order parameter, yielding a topologically different phase diagram. The Griffiths wing is broken into two pieces. A tiny wing appears close to zero anisotropy and the other is realized for a strong anisotropy. Consequently three quantum critical end points are realized. We discuss that these results can be related to various materials including a cold atom system.