2013/11/30 by Yuya Tanizaki
Physics and Astronomy · #Action (physics) #Bose gas #Bose–Einstein condensate #Bosonization #Cold Atom Physics and Bose-Einstein Condensates #Condensation #Effective action #Fermion #Functional renormalization group #Limit (mathematics) #Mathematical physics #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Quantum, superfluid, helium dynamics #Renormalization #Renormalization group #Thermodynamics #cond-mat.quant-gas #hep-ph #hep-th #nucl-th
paper · pdf · doi:10.1093/ptep/ptu009
published as Prog. Theor. Exp. Phys. (2014) 023A04 · 12 pages, 4 figures; Minor changes in wording and some comments added, references added
openalex publication_date 2014/02/10 · arxiv created 2014/02/11 · arxiv updated 2014/02/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The fermionic functional renormalization group (f-FRG) is applied to describe Bose–Einstein condensation (BEC) of dimers for a two-component fermionic system with attractive contact interaction. In order to describe the system of dimers without introducing auxiliary bosonic fields (bosonization), we propose a new exact evolution equation of the effective action in f-FRG with an infrared regulator for the fermion vertex. Then we analyze its basic properties in detail. We show explicitly that the critical temperature of the free Bose gas is obtained naturally by this method without bosonization. Methods to make systematic improvement from the deep BEC limit are briefly discussed.