2017/08/31 by Junichi Okamoto, Wen-Min Huang, Robert Höppner +1
Physics and Astronomy · #Bipartite graph #Cold Atom Physics and Bose-Einstein Condensates #Critical exponent #Critical phenomena #Hamiltonian (control theory) #Quantum many-body systems #Quantum, superfluid, helium dynamics #Renormalization #Renormalization group #Square lattice #Superfluidity #Universality (dynamical systems) #cond-mat.quant-gas
paper · pdf · doi:10.1088/1367-2630/aa9fcb
published in New Journal of Physics 20(1), 015012 (IOP Publishing) · 16 pages, 7 figures
openalex created_date 2017/08/31 · openalex publication_date 2017/12/07 · arxiv created 2018/02/01 · arxiv updated 2018/02/02 · openalex updated_date 2026/08/05
We study the critical behavior of Bose–Einstein condensation in the second band of a bipartite optical square lattice in a renormalization group framework at one-loop order. Within our field theoretical representation of the system, we approximate the system as a two-component Bose gas in three dimensions. We demonstrate that the system is in a different universality class than the previously studied condensation in a frustrated triangular lattice due to an additional Umklapp scattering term, which stabilizes the chiral superfluid order at low temperatures. We derive the renormalization group flow of the system and show that this order persists in the low energy limit. Furthermore, the renormalization flow suggests that the phase transition from the thermal phase to the chiral superfluid state is first order.