Order and supersymmetry at high filling zero-energy states on the triangular lattice.
Henley, Christopher L.
Date of Issue2012
School of Physical and Mathematical Sciences
We perform exact-diagonalization studies in d=2 dimensions for the Fendley and Schoutens model of hard-core and nearest-neighbor-excluding fermions that displays an exact nonrelativistic supersymmetry. Using clusters of all possible shapes up to 46 sites, we systematically study the behavior of the ground-state phase diagram as a function of filling. We focus on the highly degenerate zero-energy states found at fillings between 1/7 and ∼1/5. At the lower end of that interval, at filling 1/7, we explicitly show that the ground states are gapped crystals. Consistent with previous suggestions, we find that the extensive entropy of zero states peaks at a filling of ∼0.178. At the higher end of the interval, we find zero-energy ground states at fillings above 1/5, contrary to previous expectations, which display nontrivial amplitude degeneracies.
Physical review B
© 2012 American Physical Society. This paper was published in Physical Review B and is made available as an electronic reprint (preprint) with permission of American Physical Society. The paper can be found at the following official DOI: [http://dx.doi.org/10.1103/PhysRevB.86.195105]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.