Monte Carlo Studies on Classical and Quantum Random Spin Systems

经典和量子随机自旋系统的蒙特卡罗研究

• 批准号: 05804017
• 负责人: OKABE Yutaka
• 金额: $ 1.02万
• 依托单位: Tokyo Metropolitan University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05804017/
• 关键词: Monte Carlo method; Spin-glasses; Histogram method; Quantum spin system; Quantum Monte Carlo; Dispersion curve; ヒストグラス法; 量子スピン系

It is interesting to study the effect of randomness on the phase transions and critical phenomena. We nsed massive Monte Carlo simulations to get accurate numerical information on the random spin systems.We proposed to use the histogram method for the study of spin-glass problems. Calculating the replica-ovelap parameter for various temperatures and for various magnetic fields by a simulation for a single parameter, we investigated the spin-glass transition under magnetic field for the three-and four-dimensional short-ranged spin-glass models.We also investigated the thermodynamic properties of alternating-bond quantum spin systems by using the quantum Monte Carlo method. The magnetization process, the spin-spin correlation functions, and the energy dispersion curves were calcuated.

研究随机性对相变和临界现象的影响是一个有趣的问题。为了得到随机自旋系统的精确数值信息，我们采用了大量的Monte Carlo模拟，并提出了用直方图方法研究自旋玻璃问题。通过对单个参数的模拟，计算了不同温度和不同磁场下的复制椭圆参数，研究了三维和四维短程自旋玻璃模型在磁场作用下的自旋玻璃转变，并利用量子Monte Carlo方法研究了交替键量子自旋系统的热力学性质.计算了磁化过程、自旋-自旋关联函数和能量色散曲线。

项目成果

Y.Okabe.M.Kikuchi and K.Niizeki: "Application of Finite-Size Scaling to Phase Transitions and Localization-Delocalization Transitions" Computer Simulation Studies in Condensed Matter Physics V,edited by D.P.Landau, K.K.Mon and H.-B.Schuttler. (Springer, B

Y.Okabe.M.Kikuchi 和 K.Niizeki：“有限尺寸缩放在相变和定域-离域转变中的应用”凝聚态物理中的计算机模拟研究 V，由 D.P.Landau、K.K.Mon 和 H.-B 编辑。

M.Kikuchi: "Statistical Dependence and Related Topics." Computer Simulation Sudies in Condenced Matter Physics VII,edited by D.P.Landau,K.K.Mon at H.-B.Schuttler.44-56 (1994)

M.Kikuchi：“统计依赖性和相关主题。”

K.Satoh and Y.Okabe: "Critical Phenomenon in a Neural Network Model:A Localization-Delocalization Transition of Excited Clusters" J.Phys.Soc.Jpn.62. 64-71 (1993)

K.Satoh 和 Y.Okabe：“神经网络模型中的关键现象：激发簇的定位-离域转变”J.Phys.Soc.Jpn.62。

Y.Okabe and N.Kai: "Alternating Quantum Antiferro magnetic Chains with Discommensurations:A Quantum Morte Corlo Study" Proceedings of the 6th Joint EPS-APS International Conference on Physics Computing. 715-718 (1994)

Y.Okabe 和 N.Kai：“Alternating Quantum Antiferro Magnetic Chains with Discommensurations：A Quantum Morte Corlo Study”第六届 EPS-APS 国际物理计算联合会议论文集。

K.Satoh: "Critical Phenomenon in a Neural Network Model : A Localization-Delocalization Transition of Excited Clusters." J.Phys.Soc.Jpn.62. 64-71 (1993)

K.Satoh：“神经网络模型中的关键现象：兴奋簇的定位-离域转变。”