arXiv: Disordered Systems and Neural Networks最新文献_第7页

Rayleigh scattering and disorder-induced mixing of polarizations in amorphous solids at the nanoscale: 1-octyl-3-methylimidazolium chloride glass 纳米尺度下非晶固体中瑞利散射和无序极化混合:1-辛基-3-甲基咪唑氯玻璃

arXiv: Disordered Systems and Neural Networks Pub Date : 2019-06-10 DOI: 10.1103/physrevb.102.214309

M. G. Izzo, B. Wehinger, S. Cazzato, A. Matic, C. Masciovecchio, A. Gessini, G. Ruocco

{"title":"Rayleigh scattering and disorder-induced mixing of polarizations in amorphous solids at the nanoscale: 1-octyl-3-methylimidazolium chloride glass","authors":"M. G. Izzo, B. Wehinger, S. Cazzato, A. Matic, C. Masciovecchio, A. Gessini, G. Ruocco","doi":"10.1103/physrevb.102.214309","DOIUrl":"https://doi.org/10.1103/physrevb.102.214309","url":null,"abstract":"Acoustic excitations in topologically disordered media at mesoscale present anomalous features with respect to the Debye's theory. In a three-dimensional medium an acoustic excitation is characterized by its phase velocity, intensity and polarization. The so-called Rayleigh anomalies, which manifest in attenuation and retardation of the acoustic excitations, affect the first two properties. The topological disorder is, however, expected to influence also the third one. Acoustic excitations with a well-defined polarization in the continuum limit present indeed a so-called mixing of polarizations at nanoscale, as attested by experimental observations and Molecular Dynamics simulations. We provide a comprehensive experimental characterization of acoustic dynamics properties of a selected glass, 1-octyl-3-methylimidazolium chloride glass, whose heterogeneous structure at nanoscale is well-assessed. Distinctive features, which can be related to the occurrence of the Rayleigh anomalies and of the mixing of polarizations are observed. We develop, in the framework of the Random Media Theory, an analytical model that allows a quantitative description of all the Rayleigh anomalies and the mixing of polarizations. Contrast between theoretical and experimental features for the selected glass reveals an excellent agreement. The quantitative theoretical approach permits thus to demonstrate how the mixing of polarizations generates distinctive feature in the dynamic structure factor of glasses and to unambiguously identify them. The robustness of the proposed theoretical approach is validated by its ability to describe as well transverse acoustic dynamics.","PeriodicalId":8438,"journal":{"name":"arXiv: Disordered Systems and Neural Networks","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90684111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Detecting nematic order in STM/STS data with artificial intelligence 用人工智能检测STM/STS数据中的向列序

arXiv: Disordered Systems and Neural Networks Pub Date : 2019-01-30 DOI: 10.21468/SCIPOSTPHYS.8.6.087

Jeremy B. Goetz, Yi Zhang, M. Lawler

{"title":"Detecting nematic order in STM/STS data with artificial intelligence","authors":"Jeremy B. Goetz, Yi Zhang, M. Lawler","doi":"10.21468/SCIPOSTPHYS.8.6.087","DOIUrl":"https://doi.org/10.21468/SCIPOSTPHYS.8.6.087","url":null,"abstract":"Detecting the subtle yet phase defining features in Scanning Tunneling Microscopy and Spectroscopy data remains an important challenge in quantum materials. We meet the challenge of detecting nematic order from local density of states data with supervised machine learning and artificial neural networks for the difficult scenario without sharp features such as visible lattice Bragg peaks or Friedel oscillation signatures in the Fourier transform spectrum. We train the artificial neural networks to classify simulated data of isotropic and anisotropic two-dimensional metals in the presence of disorder. The supervised machine learning succeeds only with at least one hidden layer in the ANN architecture, demonstrating it is a higher level of complexity than nematic order detected from Bragg peaks which requires just two neurons. We apply the finalized ANN to experimental STM data on CaFe2As2, and it predicts nematic symmetry breaking with 99% confidence (probability 0.99), in agreement with previous analysis. Our results suggest ANNs could be a useful tool for the detection of nematic order in STM data and a variety of other forms of symmetry breaking.","PeriodicalId":8438,"journal":{"name":"arXiv: Disordered Systems and Neural Networks","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85784149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

RANDOM COMBINATORIAL OPTIMIZATION PROBLEMS: MEAN FIELD AND FINITE-DIMENSIONAL RESULTS 随机组合优化问题:平均场和有限维结果

arXiv: Disordered Systems and Neural Networks Pub Date : 2018-12-21 DOI: 10.13130/MALATESTA-ENRICO-MARIA_PHD2018-12-21

E. Malatesta

{"title":"RANDOM COMBINATORIAL OPTIMIZATION PROBLEMS: MEAN FIELD AND FINITE-DIMENSIONAL RESULTS","authors":"E. Malatesta","doi":"10.13130/MALATESTA-ENRICO-MARIA_PHD2018-12-21","DOIUrl":"https://doi.org/10.13130/MALATESTA-ENRICO-MARIA_PHD2018-12-21","url":null,"abstract":"This PhD thesis is organized as follows. In the first two chapters I will review some basic notions of statistical physics of disordered systems, such as random graph theory, the mean-field approximation, spin glasses and combinatorial optimization. The replica method will also be introduced and applied to the Sherrington-Kirkpatrick model, one of the simplest mean-field models of spin-glasses. The second part of the thesis deals with mean-field combinatorial optimization problems. The attention will be focused on the study of finite-size corrections of random integer matching problems (chapter 3) and fractional ones (chapter 4). In chapter 5 I will discuss a very general relation connecting multi-overlaps and the moments of the cavity magnetization distribution. In the third part we consider random Euclidean optimization problems. I will start solving the traveling-salesman-problem (TSP) in one dimension both in its bipartite and monopartite version (chapter 6). In chapter 7 I will discuss the possible optimal solutions of the 2-factor problem. In chapter 8 I will solve the bipartite TSP in two dimensions, in the limit of large number of points. Chapter 9 contains some conclusions.","PeriodicalId":8438,"journal":{"name":"arXiv: Disordered Systems and Neural Networks","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84421386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Localization Parameters for Interacting Particles in Disordered Two- Dimensional Lattices 无序二维晶格中相互作用粒子的局部化参数

arXiv: Disordered Systems and Neural Networks Pub Date : 2018-09-18 DOI: 10.20944/PREPRINTS201809.0327.V1

T. Chattaraj

引用次数: 0

Fano Resonances in Flat Band Networks 平带网络中的范诺共振

arXiv: Disordered Systems and Neural Networks Pub Date : 2018-01-10 DOI: 10.1007/978-3-319-99731-5_13

Ajith Ramachandran, C. Danieli, S. Flach

引用次数: 13

Kramers-Kronig relations and the properties of conductivity and permittivity in heterogeneous media 非均质介质中Kramers-Kronig关系及电导率和介电常数的性质

arXiv: Disordered Systems and Neural Networks Pub Date : 2018-01-01 DOI: 10.4236/jemaa.2018.102003

C. Bédard, A. Destexhe

引用次数: 8

Controlled trapping of single particle states on a periodic substrate by deterministic stubbing 通过确定性存根控制周期性衬底上单粒子态的捕获

arXiv: Disordered Systems and Neural Networks Pub Date : 2017-12-29 DOI: 10.1016/j.physleta.2019.125987

A. Mukherjee, A. Nandy, A. Chakrabarti

引用次数: 0

An extension of estimation of critical points in ground state for random spin systems 随机自旋系统基态临界点估计的推广

arXiv: Disordered Systems and Neural Networks Pub Date : 2017-11-09 DOI: 10.7566/JPSJ.87.015001

Masayuki Ohzeki, Yuta Kudo, Kazuyuki Tanaka

引用次数: 1

Spin Glasses: Experimental Signatures and Salient Outcomes 自旋玻璃:实验特征和显著结果

arXiv: Disordered Systems and Neural Networks Pub Date : 2017-09-29 DOI: 10.1007/978-3-319-96914-5_2

E. Vincent, Vincent Dupuis Sphynx, Phenix

引用次数: 20

Wavepacket Dynamics in One-Dimensional System with Long-Range Correlated Disorder 一维长程相关无序系统的波包动力学

arXiv: Disordered Systems and Neural Networks Pub Date : 2017-09-18 DOI: 10.1016/j.rinp.2018.01.031

H. Yamada

引用次数: 0