Chiral correlation in triangular lattice Hubbard model*

The fermionic triangular lattice Hubbard (TLH) model constitutes a playground for intriguing emergent quantum phenomena and novel exotic states in strongly correlated system. In a recent paper [1], by using mixed real- and momentum-space basis in iDMRG, a chiral spin liquid is found for intermediate onsite Coulomb interaction U between the small-U metallic phase and large-U three-sublattice magnetic phase, against the conclusion in ref. [2].
In this talk, I will focus on finite-size DMRG simulations of the TLH for system sizes that go clearly beyond [2] while also exploiting SU(2) spin symmetry. Comprehensive characterizations, including entanglement entropy, spin correlation, and chiral correlation, are carried out to distinguish the phase boundary between the above three phases. By tuning the on-site Coulomb interaction U to intermediate values, we observe for significantly large systems strong indications in favor of a chiral spin liquid. Specifically, for U10, we observe a plateau in the static chiral correlations vs. distance, and the estimated spontaneous chiral order parameter shows good agreement with ref. [1].

[1] A. Szasz, et al, arXiv:1808.00463 [cond-mat]
[2] T. Shirakawa, et al, Phys. Rev. B 96, 205130