2008/11/30 by Dominik Nickel, Michael Buballa · 6 citations
Physics and Astronomy · #Ansatz #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Cooper pair #Excitation #Ginzburg–Landau theory #Lattice (music) #Mean field theory #Pairing #Phase (matter) #Phase transition #Physics #Physics of Superconductivity and Magnetism #Quantum many-body systems #Quantum mechanics #Quasiparticle #Superconductivity #cond-mat.supr-con #hep-ph #nucl-th
paper · pdf · doi:10.1103/physrevd.79.054009
published as Phys.Rev.D79:054009,2009 · 24 pages, 18 figures; v2: minor modifications, to appear in PRD
arxiv created 2009/03/05 · openalex publication_date 2009/03/13 · arxiv updated 2010/04/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present a general framework for analyzing inhomogeneous (color-)superconducting phases in the mean-field approximation without restriction to the Ginzburg-Landau approach. As a first application, we calculate real gap functions with general one-dimensional periodic structures for a 3+1-dimensional toy model having two fermion species. The resulting solutions are energetically favored against homogeneous superconducting (BCS) and normal conducting phases in a window for the chemical potential difference \ensuremathδ\ensuremathμ which is about twice as wide as that for the most simple plane-wave ansatz (``Fulde-Ferrell phase''). At the lower end of this window, we observe the formation of a soliton lattice and a continuous phase transition to the BCS phase. At the higher end of the window the gap functions are sinusoidal, and the transition to the normal conducting phase is of first order. We also discuss the quasiparticle excitation spectrum in the inhomogeneous phase. Finally, we compare the gap functions with the known analytical solutions of the 1+1-dimensional theory.