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arXiv 1607.06968cond-mat.stat-mech
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具有长程相互作用的无规键Potts链的相变

Phase-transitions of the random bond Potts chain with long-range interactions

Jean-Christian Anglès d'Auriac, Ferenc Iglói

摘要:

我们研究了具有随机最近邻耦合的铁磁$q$态Potts链的相变,随机最近邻耦合具有方差$Δ^2$,并且具有均匀的长程相互作用,其随距离衰减为功率$r^{-(1+σ)}$,$σ>0$。在大$q$极限下,利用组合优化算法精确计算了长度为$L \le 2048$的随机样本的自由能。对于$σ< σ_c(Δ) \le 0.5$,相变保持一阶,而对于$σ_c(Δ) < σ< 1$,关联长度在相变点处变得发散。在后一种情况下,对于足够小的$Δ$,平均磁化强度是连续的,但对于较大的$Δ$,在相变点处是不连续的,因此相变是混合阶的。

英文摘要:

We study phase-transitions of the ferromagnetic $q$-state Potts chain with random nearest-neighbour couplings having a variance $Δ^2$ and with homogeneous long-range interactions, which decay with the distance as a power $r^{-(1+σ)}$, $σ>0$. In the large-$q$ limit the free-energy of random samples of length $L \le 2048$ is calculated exactly by a combinatorial optimization algorithm. The phase-transition stays first-order for $σ< σ_c(Δ) \le 0.5$, while the correlation length becomes divergent at the transition point for $σ_c(Δ) < σ< 1$. In the latter regime the average magnetization is continuous for small enough $Δ$, but for larger $Δ$ it is discontinuous at the transition point, thus the phase-transition is of mixed order.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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