We investigate the symmetric Ashkin-Teller (AT) model on the triangular lattice in the antiferromagnetic two-spin coupling region ( $J 0$ , with K the four-spin interaction. Further, we find that, in the $J \rightarrow -\infty$ limit, the critical line terminates at the decoupled point $K=0$ . From the numerical results and the exact mapping, we conjecture that this `tricritical' point ( $J \rightarrow -\infty, K=0$ ) is Berezinsky-Kosterlitz-Thouless-like and the logarithmic correction is absent. The dynamic critical exponent of the worm algorithm is estimated as $z=0.28(1)$ near $(J \rightarrow -\infty, K=0)$ .We investigate the symmetric Ashkin-Teller (AT) model on the triangular lattice in the antiferromagnetic two-spin coupling region ($J 0$, with K the four-spin interaction. Further, we find that, in the $J \rightarrow -\infty$ limit, the critical line terminates at the decoupled point $K=0$. From the numerical results and the exact mapping, we conjecture that this `tricritical' point ($J \rightarrow -\infty, K=0$) is Berezinsky-Kosterlitz-Thouless-like and the logarithmic correction is absent. The dynamic critical exponent of the worm algorithm is estimated as $z=0.28(1)$ near $(J \rightarrow -\infty, K=0)$.

Sep 16, 20100 citations

We investigate the symmetric Ashkin-Teller (AT) model on the triangular lattice in the antiferromagnetic two-spin coupling region (

J 0

, with K the four-spin interaction. Further, we find that, in the

J \rightarrow -\infty

limit, the critical line terminates at the decoupled point

K=0

. From the numerical results and the exact mapping, we conjecture that this `tricritical' point (

J \rightarrow -\infty, K=0

) is Berezinsky-Kosterlitz-Thouless-like and the logarithmic correction is absent. The dynamic critical exponent of the worm algorithm is estimated as

z=0.28(1)

near

(J \rightarrow -\infty, K=0)