邓友金
从事统计物理研究
个性化签名
- 姓名:邓友金
- 目前身份:
- 担任导师情况:
- 学位:
-
学术头衔:
博士生导师, 教育部“新世纪优秀人才支持计划”入选者
- 职称:-
-
学科领域:
数理科学
- 研究兴趣:从事统计物理研究
邓友金博士,男,1997年本科毕业于北京师范大学物理系,2000年在该校获硕士学位, 2004年在荷兰代尔夫特科技大学(Delft University of Technology)纳米科学系获博士学位。2004年9月至 2007年3月,分别在代尔夫特科技大学材料系、美国纽约大学物理系任Research Scientist;2007年4月至2008年11月,在德国海德堡大学(Heidelberg Univesity) 物理研究所做洪堡学者。
邓友金博士从事统计物理研究,成果突出,已经在物理学重要的国际期刊上发表论文30余篇,其中第一作者文章20余篇(包括6篇Physical Review Letters文章),在国际统计物理学界有一定的影响。
-
主页访问
2112
-
关注数
0
-
成果阅读
758
-
成果数
20
【期刊论文】Some geometric critical exponents for percolation and the random-cluster model
邓友金, Youjin Deng, Wei Zhang, Timothy M. Garoni, Alan D. Sokal, , and Andrea Sportiello
,-0001,():
-1年11月30日
We introduce several infinite families of new critical exponents for the random-cluster model and present scaling arguments relating them to the k-arm exponents. We then present Monte Carlo simulations confirming these predictions. These new exponents provide a convenient way to determine k-arm exponents from Monte Carlo simulations. An understanding of these exponents also leads to a radically improved implementation of the Sweeny Monte Carlo algorithm. In addition, our Monte Carlo data allow us to conjecture an exact expression for the shortest-path fractal dimension dmin in two dimensions: dmin?=(g+2)(g+18)/(32g) where g is the Coulomb-gas coupling, related to the cluster fugacity q via q=2+2 cos(gπ/2) with 2≤g≤4.
-
63浏览
-
0点赞
-
0收藏
-
0分享
-
64下载
-
0评论
-
引用
【期刊论文】Phase transitions in self-dual generalizations of the Baxter-Wu model
邓友金, Youjin Deng a, Wenan Guo b, ∗, Jouke R. Heringa c, Henk W.J. Blöte d, Bernard Nienhuis e
Nuclear Physics B 827 [FS] (2010) 406-425,-0001,():
-1年11月30日
We study two types of generalized Baxter-Wu models, by means of transfer-matrix and Monte Carlo techniques. The first generalization allows for different couplings in the up-and down-triangles, and the second generalization is to a q-state spin model with three-spin interactions. Both generalizations lead to self-dual models, so that the probable locations of the phase transitions follow. Our numerical analysis confirms that phase transitions occur at the self-dual points. For both generalizations of the Baxter-Wu model, the phase transitions appear to be discontinuous.
Generalized Baxter-Wu models, Self-dual, Phase transition
-
36浏览
-
0点赞
-
0收藏
-
0分享
-
91下载
-
0评论
-
引用
【期刊论文】Single-cluster dynamics for the random-cluster model
邓友金, Youjin Deng, Xiaofeng Qian, Henk W.J. Blote,
,-0001,():
-1年11月30日
We formulate a single-cluster Monte Carlo algorithm for the simulation of the random-cluster model. This algorithm is a generalization of the Wolff single-cluster method for the q-state Potts model to non-integer values q>1. Its results for static quantities are in a satisfactory agreement with those of the existing Swendsen-Wang-Chayes-Machta (SWCM) algorithm, which involves a full cluster decomposition of random-cluster configurations. We explore the critical dynamics of this algorithm for several two-dimensional Potts and random-cluster models. For integer q, the single-cluster algorithm can be reduced to the Wolff algorithm, for which case we find that the autocorrelation functions decay almost purely exponentially, with dynamic exponents zexp=0.07 (1), 0.521 (7), and 1.007 (9) for q=2,3, and 4 respectively. For non-integer q, the dynamical behavior of the single-cluster algorithm appears to be very dissimilar to that of the SWCM algorithm. For large critical systems, the autocorrelation function displays a range of power-law behavior as a function of time. The dynamic exponents are relatively large. We provide an explanation for this peculiar dynamic behavior.
-
58浏览
-
0点赞
-
0收藏
-
0分享
-
87下载
-
0评论
-
引用
【期刊论文】Percolation and critical O(n) loop configurations
邓友金, Chengxiang Ding, Youjin Deng, *, Wenan Guo, †, and Henk W.J. Blöte
PHYSICAL REVIEW E 79, 061118 (2009),-0001,():
-1年11月30日
We study a percolation problem based on critical loop configurations of the O(n) loop model on the honeycomb lattice. We define dual clusters as groups of sites on the dual triangular lattice that are not separated by a loop, and investigate the bond-percolation properties of these dual clusters. The universal properties at the percolation threshold are argued to match those of Kasteleyn-Fortuin random clusters in the critical Potts model. This relation is checked numerically by means of cluster simulations of several O(n) models in the range 1≤n≤2. The simulation results include the percolation threshold for several values of n, as well as the universal exponents associated with bond dilution and the size distribution of the diluted clusters at the percolation threshold. Our numerical results for the exponents are in agreement with existing Coulomb-gas results for the random-cluster model, which confirms the relation between both models. We discuss the renormalization flow of the bond-dilution parameter p as a function of n, and provide an expression that accurately describes a line of unstable fixed points as a function of n, corresponding with the percolation threshold. Furthermore, the renormalization scenario indicates the existence, in a p versus n diagram, of another line of fixed points at p=1, which is stable with respect to p.
-
49浏览
-
0点赞
-
0收藏
-
0分享
-
86下载
-
0评论
-
引用
【期刊论文】Crossing bonds in the random-cluster model
邓友金, Wenan Guo, Youjin Deng, Henk W.J. Blote
,-0001,():
-1年11月30日
We derive the scaling dimension associated with crossing bonds in the random-cluster representation of the two-dimensional Potts model, by means of a mapping on the Coulomb gas. The scaling field associated with crossing bonds appears to be irrelevant, on the critical as well as on the tricritical branch. The latter result stands in a remarkable contrast with the existing result for the tricritical O(n) model that crossing bonds are relevant. In order to obtain independent confirmation of the Coulomb gas result for the crossing-bond exponent, we perform a finite-size-scaling analysis based on numerical transfer-matrix calculations.
-
41浏览
-
0点赞
-
0收藏
-
0分享
-
71下载
-
0评论
-
引用
【期刊论文】A worm algorithm for the fully-packed loop model
邓友金, Wei Zhang, Timothy M. Garoni*, Youjin Deng
Preprint submitted to Nuclear Physics B 14 November 2008,-0001,():
-1年11月30日
We present a Markov-chain Monte Carlo algorithm of worm type that correctly simulates the fully-packed loop model with n = 1 on the honeycomb lattice, and we prove that it is ergodic and has uniform stationary distribution. The honeycomblattice fully-packed loop model with n=1 is equivalent to the zero-temperature triangular-lattice antiferromagnetic Ising model, which is fully frustrated and notoriously difficult to simulate. We test this worm algorithm numerically and estimate the dynamic exponent zexp=0.515(8). We also measure several static quantities of interest, including loop-length and face-size moments. It appears numerically that the face-size moments are governed by the magnetic dimension for percolation.
Monte Carlo, worm algorithm, fully-packed loop model
-
30浏览
-
0点赞
-
0收藏
-
0分享
-
56下载
-
0评论
-
引用
邓友金, Tsong-Ming Liaw, *, Ming-Chang Huang, †, Yu-Pin Luo, Simon C. Lin, Yen-Liang Chou, and Youjin Deng
PHYSICAL REVIEW E 77, 010101 (R) (2008),-0001,():
-1年11月30日
The conventional periodic boundary conditions in two dimensions are extended to general boundary conditions, prescribed by primitive vector pairs that may not coincide with the coordinate axes. This extension is shown to be unambiguously specified by the twisting scheme. Equivalent relations between different twist settings are constructed explicitly. The classification of finite-size scaling functions is discussed based on the equivalent relations. A self-similar pattern for distinct classes of finite-size scaling functions is shown to appear on the plane that parametrizes the toroidal geometry.
-
43浏览
-
0点赞
-
0收藏
-
0分享
-
39下载
-
0评论
-
引用
【期刊论文】Percolation transitions in two dimensions
邓友金, Xiaomei Feng, , Youjin Deng and Henk W.J. Blote
,-0001,():
-1年11月30日
We investigate bond- and site-percolation models on several two-dimensional lattices numerically, by means of transfer-matrix calculations and Monte Carlo simulations. The lattices include the square, triangular, honeycomb kagome and diced lattices with nearest-neighbor bonds, and the square lattice with nearest- and next-nearest-neighbor bonds. Results are presented for the bondpercolation thresholds of the kagome and diced lattices, and the site-percolation thresholds of the square, honeycomb and diced lattices. We also include the bond- and site-percolation thresholds for the square lattice with nearest-and next-nearest-neighbor bonds. We find that corrections to scaling behave according to the second temperature dimension Xt2=4 predicted by the Coulomb gas theory and the theory of conformal invariance. In several cases there is evidence for an additional term with the same exponent, but modified by a logarithmic factor. Only for the site-percolation problem on the triangular lattice such a logarithmic term appears to be small or absent. The amplitude of the power-law correction associated with Xt2=4 is found to be dependent on the orientation of the lattice with respect to the cylindrical geometry of the finite systems.
-
44浏览
-
0点赞
-
0收藏
-
0分享
-
50下载
-
0评论
-
引用
邓友金, Youjin Deng, *, Timothy M. Garoni, †, and Alan D. Sokal, , ‡
PHYSICAL REVIEW LETTERS 19 JANUARY 2007 PRL 98, 030602 (2007),-0001,():
-1年11月30日
We present Monte Carlo simulations of the spanning-forest model (q→0 limit of the ferromagnetic Potts model) in spatial dimensions d=3,4,5. We show that, in contrast to the two-dimensional case, the model has a ferromagnetic second-order phase transition at a finite positive value wc. We present numerical estimates of wc and of the thermal and magnetic critical exponents. We conjecture that the upper critical dimension is 6.
-
30浏览
-
0点赞
-
0收藏
-
0分享
-
52下载
-
0评论
-
引用
【期刊论文】Geometric properties of two-dimensional O(n) loop configurations
邓友金, Chengxiang Ding, Xiaofeng Qian, Youjin Deng, Wenan Guo and Henk W.J. Blote,
,-0001,():
-1年11月30日
We study the fractal geometry of O(n) loop configurations in two dimensions by means of scaling and a Monte Carlo method, and compare the results with predictions based on the Coulomb gas technique. The Monte Carlo algorithm is applicable to models with noninteger n and uses local updates. Although these updates typically lead to nonlocal modifications of loop connectivities, the number of operations required per update is only of order one. The Monte Carlo algorithm is applied to the O(n) model for several values of n, including noninteger ones. We thus determine scaling exponents that describe the fractal nature of O(n) loops at criticality. The results of the numerical analysis agree with the theoretical predictions.
-
44浏览
-
0点赞
-
0收藏
-
0分享
-
39下载
-
0评论
-
引用