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Atsushi Yamagata

Publications and source records attributed to Atsushi Yamagata.

6 recordsLinked to original sources
arXiv1996

Universality in the Three-Dimensional Hard-Sphere Lattice Gas

We perform Monte Carlo simulations of the hard-sphere lattice gas on the body-centred cubic lattice with nearest neighbour exclusion. We get the critical exponents, $β/ν= 0.311(8)$ and $γ/ν= 2.38(2)$, where $β$, $γ$, and $ν$ are the critical exponents of the staggered density, the staggered compressibility, and the correlation length, respectively. The values of the hard-sphere lattice gas on the simple cubic lattice agree with them but those of the three-dimensional Ising model do not. This supports that the hard-sphere lattice gas does not fall into the Ising universality class in three dimensions.

cond-mat↗
arXiv1995

Critical activity of the hard-sphere lattice gas on the body-centred cubic lattice

This is the first Monte Carlo study of the hard-sphere lattice gas with nearest neighbour exclusion on the body-centred cubic lattice. We estimate the critical activity to be $0.7223 \pm 0.0003$. This result confirms that there is a re-entrant phase transition of an antiferromagnetic Ising model in an external field and a Blume-Emery-Griffiths model on the body-centred cubic lattice.

cond-mat↗
arXiv1995

Critical phenomena of the hard-sphere lattice gas on the simple cubic lattice

We study the critical phenomena of the hard-sphere lattice gas on the simple cubic lattice with nearest neighbour exclusion by the Monte Carlo method. We get the critical exponents, $β/ ν$ = 0.313(9) and $γ/ ν$ = 2.37(2), where $β$ is the critical exponent for the staggered density, $γ$ for the staggered compressibility, and $ν$ for the correlation length.

cond-mat↗
arXiv1994

Finite-size effects of dimensional crossover in quasi-two-dimensional three-state Potts model

A nearest neighbour spin pair of the quasi-two-dimensional three-state Potts model interacts with the strength $J(>0)$ in the $xy$-plane and with $λJ$ $(0\le λ\ll 1)$ in the $z$-axis. The phase transition is of second-order when $λ= 0$ and is of first-order when $λ> 0$. The dimensional crossover occurs with a change of the order of the phase transition. We study the finite-size effects of the phenomenon by using a Monte Carlo method with a multi-spin coding technique. The prediction of the finite-size scaling theory is consistent with the Monte Carlo results.

cond-mat↗
arXiv1994

Absence of re-entrant phase transition of the antiferromagnetic Ising model on the simple cubic lattice: Monte Carlo study of the hard-sphere lattice gas

We perform the Monte Carlo simulations of the hard-sphere lattice gas on the simple cubic lattice with nearest neighbour exclusion. The critical activity is estimated, $z_{\rm c} = 1.0588 \pm 0.0003$. Using a relation between the hard-sphere lattice gas and the antiferromagnetic Ising model in an external magnetic field, we conclude that there is no re-entrant phase transition of the latter on the simple cubic lattice.

cond-mat↗