arXiv: Mesoscale and Nanoscale Physics最新文献_第2页

Orbital Edelstein effect in topological insulators 拓扑绝缘体中的轨道Edelstein效应

arXiv: Mesoscale and Nanoscale Physics Pub Date : 2021-02-01 DOI: 10.21203/RS.3.RS-150034/V1

K. Osumi, Tiantian Zhang, S. Murakami

引用次数: 1

Role of Berry curvature in the generation of spin currents in Rashba systems Rashba系统中Berry曲率在自旋电流产生中的作用

arXiv: Mesoscale and Nanoscale Physics Pub Date : 2021-01-12 DOI: 10.1103/PHYSREVB.103.165401

Priyadarshini Kapri, B. Dey, T. Ghosh

{"title":"Role of Berry curvature in the generation of spin currents in Rashba systems","authors":"Priyadarshini Kapri, B. Dey, T. Ghosh","doi":"10.1103/PHYSREVB.103.165401","DOIUrl":"https://doi.org/10.1103/PHYSREVB.103.165401","url":null,"abstract":"We study the background (equilibrium), linear and nonlinear spin currents in 2D Rashba spin-orbit coupled systems with Zeeman splitting and in 3D noncentrosymmetric metals using modified spin current operator by inclusion of the anomalous velocity. The linear spin Hall current arises due to the anomalous velocity of charge carriers induced by the Berry curvature. The nonlinear spin current occurs due to the band velocity and/or the anomalous velocity. For 2D Rashba systems, the background spin current saturates at high Fermi energy (independent of the Zeeman coupling), linear spin current exhibits a plateau at the Zeeman gap and nonlinear spin currents are peaked at the gap edges. The magnitude of the nonlinear spin current peaks enhances with the strength of Zeeman interaction. The linear spin current is polarized out of plane, while the nonlinear ones are polarized in-plane. We witness pure anomalous nonlinear spin current with spin polarization along the direction of propagation. In 3D noncentrosymmetric metals, background and linear spin currents are monotonically increasing functions of Fermi energy, while nonlinear spin currents vary non-monotonically as a function of Fermi energy and are independent of the Berry curvature. These findings may provide useful information to manipulate spin currents in Rashba spin-orbit coupled systems.","PeriodicalId":8465,"journal":{"name":"arXiv: Mesoscale and Nanoscale Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78095834","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: 6

Recent Advances in Superlattice Frequency Multipliers 超晶格乘频器的最新进展

arXiv: Mesoscale and Nanoscale Physics Pub Date : 2021-01-05 DOI: 10.1007/978-94-024-2082-1_8

Y. Shevchenko, A. Apostolakis, Mauro F. Pereira

引用次数: 3

Higher-order topology in plasmonic Kagome lattices 等离子体Kagome晶格的高阶拓扑

arXiv: Mesoscale and Nanoscale Physics Pub Date : 2020-12-17 DOI: 10.1063/5.0040955

M. Proctor, M. Blanco de Paz, D. Bercioux, Aitzol Garc'ia-Etxarri, P. Arroyo Huidobro

引用次数: 18

Entangling nuclear spins in distant quantum dots via an electron bus 通过电子总线在远距离量子点中纠缠核自旋

arXiv: Mesoscale and Nanoscale Physics Pub Date : 2020-12-17 DOI: 10.1103/PhysRevApplied.18.014009

Miguel Núñez Bello, M. Benito, M. Schuetz, G. Platero, G. Giedke

引用次数: 0

Unconventional level attraction in cavity axion polariton of antiferromagnetic topological insulator 反铁磁拓扑绝缘体轴子极化子腔中的非常规能级吸引

arXiv: Mesoscale and Nanoscale Physics Pub Date : 2020-12-17 DOI: 10.21203/RS.3.RS-120479/V1

Yang Xiao, Huaiqiang Wang, Dinghui Wang, R. Lu, Xiaohong Yan, Hong Guo, C.-M. Hu, K. Xia, Haijun Zhang, D. Xing

{"title":"Unconventional level attraction in cavity axion polariton of antiferromagnetic topological insulator","authors":"Yang Xiao, Huaiqiang Wang, Dinghui Wang, R. Lu, Xiaohong Yan, Hong Guo, C.-M. Hu, K. Xia, Haijun Zhang, D. Xing","doi":"10.21203/RS.3.RS-120479/V1","DOIUrl":"https://doi.org/10.21203/RS.3.RS-120479/V1","url":null,"abstract":"\u0000 Strong coupling between cavity photons and various excitations in condensed matters boosts the field of light-matter interaction and generates several exciting sub-fields, such as cavity optomechanics and cavity magnon polariton. Axion quasiparticles, emerging in topological insulators, were predicted to strongly couple with the light and generate the so-called axion polariton. Here, we demonstrate that there arises a gapless level attraction in cavity axion polariton of antiferromagnetic topological insulators, which originates from a nonlinear interaction between axion and the odd-order resonance of cavity. Such a novel level attraction is essentially different from conventional level attractions with the mechanism of either a linear coupling or a dissipation-mediated interaction, and also different from the level repulsion induced by the strong coupling in common polaritons. Our results reveal a new mechanism of level attractions, and open up new roads for exploring the axion polariton with cavity technologies. They have potential applications for quantum information and dark matter research.","PeriodicalId":8465,"journal":{"name":"arXiv: Mesoscale and Nanoscale Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86053459","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

Quantized electrochemical transport in Weyl semimetals Weyl半金属的量化电化学输运

arXiv: Mesoscale and Nanoscale Physics Pub Date : 2020-12-16 DOI: 10.1103/physrevb.103.035102

R. Flores-Calder'on, A. Mart'in-Ruiz

引用次数: 6

Sondheimer oscillations as a probe of non-ohmic flow in type-II Weyl semimetal WP2 Sondheimer振荡对ii型Weyl半金属WP2非欧姆流动的探测

arXiv: Mesoscale and Nanoscale Physics Pub Date : 2020-12-15 DOI: 10.5281/zenodo.4675599

M. V. Delft, Yaxian Wang, C. Putzke, J. Oswald, Georgios Varnavides, Christina A. C. Garcia, Chunyu Guo, H. Schmid, Vicky Süβ, H. Borrmann, J. Diaz, Yan Sun, C. Felser, B. Gotsmann, P. Narang, P. Moll

{"title":"Sondheimer oscillations as a probe of non-ohmic flow in type-II Weyl semimetal WP2","authors":"M. V. Delft, Yaxian Wang, C. Putzke, J. Oswald, Georgios Varnavides, Christina A. C. Garcia, Chunyu Guo, H. Schmid, Vicky Süβ, H. Borrmann, J. Diaz, Yan Sun, C. Felser, B. Gotsmann, P. Narang, P. Moll","doi":"10.5281/zenodo.4675599","DOIUrl":"https://doi.org/10.5281/zenodo.4675599","url":null,"abstract":"\u0000 As conductors in electronic applications shrink, microscopic conduction processes lead to strong deviations from Ohm’s law. Depending on the length scales of momentum conserving (lMC) and relaxing (lMR) electron scattering, and the device size (d), current flows may shift from ohmic to ballistic to hydrodynamic regimes and more exotic mixtures thereof. So far, an in situ, in-operando methodology to obtain these parameters self-consistently within a micro/nanodevice, and thereby identify its conduction regime, is critically lacking. In this context, we exploit Sondheimer oscillations, semi-classical magnetoresistance oscillations due to helical electronic motion, as a method to obtain lMR in micro-devices even when lMR>>d. This gives information on the bulk lMR complementary to quantum oscillations, which are sensitive to all scattering processes. We extract lMR from the Sondheimer amplitude in the topological semi-metal WP2, at elevated temperatures up to T~50 K, in a range most relevant for hydrodynamic transport phenomena. Our data on μm-sized devices are in excellent agreement with experimental reports of the large bulk lMR and thus confirm that WP2 can be microfabricated without degradation. Indeed, the measured scattering rates match well with those of theoretically predicted electron-phonon scattering, thus supporting the notion of strong momentum exchange between electrons and phonons in WP2 at these temperatures. These results conclusively establish Sondheimer oscillations as a quantitative probe of lMR in micro-devices in studying non-ohmic electron flow.","PeriodicalId":8465,"journal":{"name":"arXiv: Mesoscale and Nanoscale Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78424127","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

An Iterative Machine Learning Approach for Discovering Unexpected Thermal Conductivity Enhancement in Aperiodic Superlattices 在非周期超晶格中发现意想不到的热导率增强的迭代机器学习方法

arXiv: Mesoscale and Nanoscale Physics Pub Date : 2020-12-15 DOI: 10.1115/1.0004973v

P. R. Chowdhury, X. Ruan

{"title":"An Iterative Machine Learning Approach for Discovering Unexpected Thermal Conductivity Enhancement in Aperiodic Superlattices","authors":"P. R. Chowdhury, X. Ruan","doi":"10.1115/1.0004973v","DOIUrl":"https://doi.org/10.1115/1.0004973v","url":null,"abstract":"While machine learning (ML) has shown increasing effectiveness in optimizing materials properties under known physics, its application in challenging conventional wisdom and discovering new physics still remains challenging due to its interpolative nature. In this work, we demonstrate the potential of using ML for such applications by implementing an adaptive ML-accelerated search process that can discover unexpected lattice thermal conductivity ($kappa_l$) enhancement instead of reduction in aperiodic superlattices (SLs) as compared to periodic superlattices. We use non-equilibrium molecular dynamics (NEMD) simulations for high-fidelity calculations of $kappa_l$ for a small fraction of SLs in the search space, along with a convolutional neural network (CNN) which can rapidly predict $kappa_l$ for a large number of structures. To ensure accurate prediction by the CNN for the target unknown structures, we iteratively identify aperiodic SLs containing structural features which lead to locally enhanced thermal transport, and include them as additional training data for the CNN in each iteration. As a result, our CNN can accurately predict the high $kappa_l$ of aperiodic SLs that are absent from the initial training dataset, which allows us to identify the previously unseen exceptional structures. The identified RML structures exhibit increased coherent phonon contribution to thermal conductivity owing to the presence of closely spaced interfaces. Our work describes a general purpose machine learning approach for identifying low-probability-of-occurrence exceptional solutions within an extremely large subspace and discovering the underlying physics.","PeriodicalId":8465,"journal":{"name":"arXiv: Mesoscale and Nanoscale Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78929156","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

Probing non-Hermitian phase transitions in curved space via quench dynamics 用淬灭动力学探测弯曲空间中的非厄米相变

arXiv: Mesoscale and Nanoscale Physics Pub Date : 2020-12-14 DOI: 10.1103/PHYSREVB.103.155417

Ygor Par'a, G. Palumbo, T. Macrì

引用次数: 6