arXiv: Disordered Systems and Neural Networks最新文献_第6页

Role of fluctuations in the yielding transition of two-dimensional glasses 波动在二维玻璃屈服转变中的作用

arXiv: Disordered Systems and Neural Networks Pub Date : 2019-12-12 DOI: 10.1103/PHYSREVRESEARCH.2.023203

M. Ozawa, L. Berthier, G. Biroli, G. Tarjus

引用次数: 16

Quenched vs Annealed: Glassiness from SK to SYK 淬火与退火:从SK到SYK的玻璃性

arXiv: Disordered Systems and Neural Networks Pub Date : 2019-11-26 DOI: 10.1103/PHYSREVX.10.031026

C. Baldwin, C. Baldwin, Brian Swingle

引用次数: 18

Influence of weak disorder on the dynamical quantum phase transitions in the anisotropic XY chain 弱无序对各向异性XY链中动态量子相变的影响

arXiv: Disordered Systems and Neural Networks Pub Date : 2019-11-03 DOI: 10.1103/physrevb.102.014207

Kaiyuan Cao, Wenwen Li, Ming Zhong, P. Tong

{"title":"Influence of weak disorder on the dynamical quantum phase transitions in the anisotropic XY chain","authors":"Kaiyuan Cao, Wenwen Li, Ming Zhong, P. Tong","doi":"10.1103/physrevb.102.014207","DOIUrl":"https://doi.org/10.1103/physrevb.102.014207","url":null,"abstract":"We study the effects of disorder on the dynamical quantum phase transitions (DQPTs) in the transverse-field anisotropic XY chain by numerically calculating the Loschmidt echo after quench. By comparing the results with that of the homogeneous chain, we find that when the quench crosses the Ising transition, the small disorder will cause a new critical point. As the disorder increases, more critical points of the DQPTs will occur, constituting a critical region. In the quench across the anisotropic transition, since there are already two dynamical phase transitions in the homogeneous chain, the disorder will cause a critical region near the critical point, and the width of the critical region increases by the disordered strength. In the case of quench passing through two critical lines, the small disorder leads to the system to have three additional critical points. When the quench is in the ferromagnetic phase, the large disorder causes the two critical points of the homogeneous case to become a critical region. And for the quench in the paramagnetic phase, the larger disorder will cause the DQPTs to disappear.","PeriodicalId":8438,"journal":{"name":"arXiv: Disordered Systems and Neural Networks","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77784161","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: 8

Jamming and replica symmetry breaking of weakly disordered crystals 弱无序晶体的干扰与复制对称性破缺

arXiv: Disordered Systems and Neural Networks Pub Date : 2019-10-31 DOI: 10.1103/PHYSREVRESEARCH.2.033220

Harukuni Ikeda

引用次数: 7

Moiré pattern of a spin liquid and a Néel magnet in the Kitaev model 基塔耶夫模型中自旋液体和nsamel磁体的莫尔条纹

arXiv: Disordered Systems and Neural Networks Pub Date : 2019-10-30 DOI: 10.1103/PHYSREVB.102.094207

R. Wang, P. Wang, K. L. Zhang, Z. Song

{"title":"Moiré pattern of a spin liquid and a Néel magnet in the Kitaev model","authors":"R. Wang, P. Wang, K. L. Zhang, Z. Song","doi":"10.1103/PHYSREVB.102.094207","DOIUrl":"https://doi.org/10.1103/PHYSREVB.102.094207","url":null,"abstract":"A moire pattern occurs when two periodic structures in a system have a slight mismatch period, resulting the coexistence of distinct phases in different large-scale spacial regions of the same system. Two periodic structures can arise from periodic electric and magnetic fields, respectively. We investigated the moire pattern via a dimerized Kitaev spin chain with a periodic transverse field, which can be mapped onto the system of dimerized spinless fermions with p-wave superconductivity. The exact solution for staggered field demonstrated that the ground state has two distinct phases: (i) Neel magnetic phase for nonzero field, (ii) Spin liquid phase due to the emergence of isolated flat Bogoliubov--de Gennes band for vanishing field. We computed the staggered magnetization and local density of states (textrm{LDOS}) for the field with a slight difference period to the chain lattice. Numerical simulation demonstrated that such two phases appear alternatively along the chain with a long beat period. Additionally, we proposed a dynamic scheme to detect the Moire fringes based on the measurement of Loschmidt echo (textrm{LE}) in the presence of local perturbation.","PeriodicalId":8438,"journal":{"name":"arXiv: Disordered Systems and Neural Networks","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82934351","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: 1

Avalanche induced coexisting localized and thermal regions in disordered chains 雪崩诱导无序链中局部区和热区共存

arXiv: Disordered Systems and Neural Networks Pub Date : 2019-10-23 DOI: 10.1103/physrevresearch.2.033262

P. Crowley, A. Chandran

引用次数: 37

Experimental probes of Stark many-body localization Stark多体定位的实验探针

arXiv: Disordered Systems and Neural Networks Pub Date : 2019-10-02 DOI: 10.1103/physrevb.102.054206

S. Taylor, M. Schulz, F. Pollmann, R. Moessner

{"title":"Experimental probes of Stark many-body localization","authors":"S. Taylor, M. Schulz, F. Pollmann, R. Moessner","doi":"10.1103/physrevb.102.054206","DOIUrl":"https://doi.org/10.1103/physrevb.102.054206","url":null,"abstract":"Recent work has focused on exploring many-body localization (MBL) in systems without quenched disorder: one such proposal is Stark MBL in which small perturbations to a strong linear potential yield localization. However, as with conventional MBL, it is challenging to experimentally distinguish between non-interacting localization and true MBL. In this paper we show that several existing experimental probes, designed specifically to differentiate between these scenarios, work similarly in the Stark MBL setting. In particular we show that a modified spin-echo response (DEER) shows clear signs of a power-law decay for Stark MBL while quickly saturating for disorder-free Wannier-Stark localization. Further, we observe the characteristic logarithmic-in-time spreading of quantum mutual information in the Stark MBL regime, and an absence of spreading in a non-interacting Stark-localized system. We also show that there are no significant differences in several existing MBL measures for a system consisting of softcore bosons with repulsive on-site interactions. Lastly we show why curvature or small disorder are needed for an accurate reproduction of MBL phenomenology, and how this may be illustrated in experiment. This also connects with recent progress on Hilbert space fragmentation in ``fractonic'' models with conserved dipole moment.","PeriodicalId":8438,"journal":{"name":"arXiv: Disordered Systems and Neural Networks","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89900540","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: 41

Small-worldness favours network inference 小世界有利于网络推理

arXiv: Disordered Systems and Neural Networks Pub Date : 2019-09-03 DOI: 10.13140/RG.2.2.30449.84329

R. Garc'ia, Arturo C. Mart'i, C. Cabeza, N. Rubido

{"title":"Small-worldness favours network inference","authors":"R. Garc'ia, Arturo C. Mart'i, C. Cabeza, N. Rubido","doi":"10.13140/RG.2.2.30449.84329","DOIUrl":"https://doi.org/10.13140/RG.2.2.30449.84329","url":null,"abstract":"A main goal in the analysis of a complex system is to infer its underlying network structure from time-series observations of its behaviour. The inference process is often done by using bi-variate similarity measures, such as the cross-correlation (CC), however, the main factors favouring or hindering its success are still puzzling. Here, we use synthetic neuron models in order to reveal the main topological properties that frustrate or facilitate inferring the underlying network from CC measurements. Specifically, we use pulse-coupled Izhikevich neurons connected as in the Caenorhabditis elegans neural networks as well as in networks with similar randomness and small-worldness. We analyse the effectiveness and robustness of the inference process under different observations and collective dynamics, contrasting the results obtained from using membrane potentials and inter-spike interval time-series. We find that overall, small-worldness favours network inference and degree heterogeneity hinders it. In particular, success rates in C. elegans networks -- that combine small-world properties with degree heterogeneity -- are closer to success rates in Erdos-Renyi network models rather than those in Watts-Strogatz network models. These results are relevant to understand better the relationship between topological properties and function in different neural networks.","PeriodicalId":8438,"journal":{"name":"arXiv: Disordered Systems and Neural Networks","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76513696","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: 0

Disorder in twisted bilayer graphene 扭曲双层石墨烯的无序性

arXiv: Disordered Systems and Neural Networks Pub Date : 2019-08-07 DOI: 10.1103/PHYSREVRESEARCH.2.023325

Justin H. Wilson, Yixing Fu, S. Sarma, J. Pixley

{"title":"Disorder in twisted bilayer graphene","authors":"Justin H. Wilson, Yixing Fu, S. Sarma, J. Pixley","doi":"10.1103/PHYSREVRESEARCH.2.023325","DOIUrl":"https://doi.org/10.1103/PHYSREVRESEARCH.2.023325","url":null,"abstract":"We develop a theory for a qualitatively new type of disorder in condensed matter systems arising from local twist-angle fluctuations in two strongly coupled van der Waals monolayers twisted with respect to each other to create a flat band moire superlattice. The new paradigm of 'twist angle disorder' arises from the currently ongoing intense research activity in the physics of twisted bilayer graphene. In experimental samples of pristine twisted bilayer graphene, which are nominally free of impurities and defects, the main source of disorder is believed to arise from the unavoidable and uncontrollable non-uniformity of the twist angle across the sample. To address this new physics of twist-angle disorder, we develop a real-space, microscopic model of twisted bilayer graphene where the angle enters as a free parameter. In particular, we focus on the size of single-particle energy gaps separating the miniband from the rest of the spectrum, the Van Hove peaks, the renormalized Dirac cone velocity near charge neutrality, and the minibandwidth. We find that the energy gaps and minibandwidth are strongly affected by disorder while the renormalized velocity remains virtually unchanged. We discuss the implications of our results for the ongoing experiments on twisted bilayer graphene. Our theory is readily generalized to future studies of twist angle disorder effects on all electronic properties of moire superlattices created by twisting two coupled van der Waals materials with respect to each other.","PeriodicalId":8438,"journal":{"name":"arXiv: Disordered Systems and Neural Networks","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80253547","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: 42

Statistics of correlation functions in the random Heisenberg chain 随机海森堡链中相关函数的统计

arXiv: Disordered Systems and Neural Networks Pub Date : 2019-06-25 DOI: 10.21468/scipostphys.7.5.064

Luis Colmenarez, P. McClarty, M. Haque, D. J. Luitz

{"title":"Statistics of correlation functions in the random Heisenberg chain","authors":"Luis Colmenarez, P. McClarty, M. Haque, D. J. Luitz","doi":"10.21468/scipostphys.7.5.064","DOIUrl":"https://doi.org/10.21468/scipostphys.7.5.064","url":null,"abstract":"Ergodic quantum many-body systems satisfy the eigenstate thermalization hypothesis (ETH). However, strong disorder can destroy ergodicity through many-body localization (MBL) -- at least in one dimensional systems -- leading to a clear signal of the MBL transition in the probability distributions of energy eigenstate expectation values of local operators. For a paradigmatic model of MBL, namely the random-field Heisenberg spin chain, we consider the full probability distribution of eigenstate correlation functions across the entire phase diagram. We find gaussian distributions at weak disorder, as predicted by pure ETH. At intermediate disorder -- in the thermal phase -- we find further evidence for anomalous thermalization in the form of heavy tails of the distributions. In the MBL phase, we observe peculiar features of the correlator distributions: a strong asymmetry in $S_i^z S_{i+r}^z$ correlators skewed towards negative values; and a multimodal distribution for spin-flip correlators. A quantitative quasi-degenerate perturbation theory calculation of these correlators yields a surprising agreement of the full distribution with the exact results, revealing, in particular, the origin of the multiple peaks in the spin-flip correlator distribution as arising from the resonant and off-resonant admixture of spin configurations. The distribution of the $S_i^zS_{i+r}^z$ correlator exhibits striking differences between the MBL and Anderson insulator cases.","PeriodicalId":8438,"journal":{"name":"arXiv: Disordered Systems and Neural Networks","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89098544","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: 21