##
Spin liquid on Kagome lattice

Ying Ran**, MIT**
__Abstract:__
We perform a Gutzwiller projected
wavefunction study for the spin-1/2 Heisenberg model on the Kagome lattice
to compare
energies of several spin-liquid states. The result indicates that a
U(1)-Dirac
spin-liquid state has the lowest energy. Furthermore, even without
variational parameters, the energy turns out to be very close to that
found by exact diagonalization. We show that such a U(1)-Dirac state
can be a stable quantum phase whose low energy physics is governed by
four
flavors of two-component Dirac fermions coupled to a U(1) gauge field.
These
results are discussed in the context of recent experiments on
ZnCu_{3}(OH)_{6}Cl_{2}.