2014/11/30 by Samuel Bieri, Laura Messio, Bernard Bernu +1 · 1 citation
Physics and Astronomy · #cond-mat.str-el #cond-mat.other
paper · pdf · doi:10.1103/physrevb.92.060407
published as Phys. Rev. B 92, 060407(R) (2015) · 5+6 pages, 7 figs; refs added, typos corrected; discussion and refs updated, minor corrections; replaced w. published version
arxiv created 2015/08/14 · arxiv updated 2016/02/05
Motivated by recent experiments on the Heisenberg S=1/2 quantum spin liquid candidate material kapellasite, we classify all possible chiral (time-reversal symmetry breaking) spin liquids with fermionic spinons on the kagome lattice. We obtain the phase diagram for the physically relevant extended Heisenberg model, comparing the energies of a wide range of microscopic variational wave functions. We propose that, at low temperature, kapellasite exhibits a gapless chiral spin liquid phase with spinon Fermi surfaces. This two-dimensional state inherits many properties of the nearby one-dimensional phase of decoupled anti-ferromagnetic spin chains, but also shows some remarkable differences. We discuss the spin structure factors and other physical properties.