arXiv - PHYS - Mesoscale and Nanoscale Physics最新文献_第5页

Distinguishing different stackings in WSe2 bilayers grown Using Chemical Vapor Deposition 区分使用化学气相沉积法生长的 WSe2 双层膜中的不同叠层

arXiv - PHYS - Mesoscale and Nanoscale Physics Pub Date : 2024-09-13 DOI: arxiv-2409.08617

Aymen Mahmoudi, Meryem Bouaziz, Davide Romani, Marco Pala, Aurelien Thieffry, Thibault Brule, Julien Chaste, Fabrice Oehler, Abdelkarim Ouerghi

{"title":"Distinguishing different stackings in WSe2 bilayers grown Using Chemical Vapor Deposition","authors":"Aymen Mahmoudi, Meryem Bouaziz, Davide Romani, Marco Pala, Aurelien Thieffry, Thibault Brule, Julien Chaste, Fabrice Oehler, Abdelkarim Ouerghi","doi":"arxiv-2409.08617","DOIUrl":"https://doi.org/arxiv-2409.08617","url":null,"abstract":"The stacking order of two-dimensional transition metal dichalcogenides (TMDs)\u0000is attracting tremendous interest as an essential component of van der Waals\u0000heterostructures. A common and fast approach to distinguish between the AAprime\u0000(2H) and AB (3R) configurations uses the relative edge orientation of each\u0000triangular layer (theta) from optical images. Here, we highlight that this\u0000method alone is not sufficient to fully identify the stacking order. Instead we\u0000propose a model and methodology to accurately determine the bilayer\u0000configuration of WSe2 using second harmonic generation (SHG) and Raman\u0000spectroscopy. We demonstrate that the SHG response of the AB phase (theta = 0)\u0000deg layers is more intense than the signal from the single layer structure.\u0000However, the SHG totally vanishes in the AAprime and ABprime phases (theta = 60\u0000deg) and 0 deg respectively) of homo-bilayer WSe2. Also, several optical\u0000features of homo-bilayer WSe2 are found to depend on the details of the\u0000stacking order, with the difference being the clearest in the low frequency\u0000(LF) Raman frequencies, as confirmed by DFT simulation. This allows\u0000unambiguous, high-throughput, nondestructive identification of stacking order\u0000in TMDs, which is not robustly addressed in this emerging research area.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142253611","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

Vanishing bulk heat flow in the nu=0 quantum Hall ferromagnet in monolayer graphene 单层石墨烯中 nu=0 量子霍尔铁磁体的消失体热流

arXiv - PHYS - Mesoscale and Nanoscale Physics Pub Date : 2024-09-13 DOI: arxiv-2409.08878

Raphaëlle Delagrange, Manjari Garg, Gaëlle Le Breton, Aifei Zhang, Quan Dong, Yong Jin, Kenji Watanabe, Takashi Taniguchi, Preden Roulleau, Olivier Maillet, Patrice Roche, François D. Parmentier

引用次数: 0

Enigmatic 2+6/13 Filling Factor: A Prototype Intermittent Topological State 神秘的 2+6/13 填充因子：间歇拓扑原型

arXiv - PHYS - Mesoscale and Nanoscale Physics Pub Date : 2024-09-13 DOI: arxiv-2409.09002

Sudipto Das, Sahana Das, Sudhansu S. Mandal

引用次数: 0

Full minimal coupling Maxwell-TDDFT: an ab initio QED framework beyond the dipole approximation 全最小耦合麦克斯韦-TDDFT：超越偶极近似的原子序数 QED 框架

arXiv - PHYS - Mesoscale and Nanoscale Physics Pub Date : 2024-09-13 DOI: arxiv-2409.08959

Franco P. Bonafé, Esra Ilke Albar, Sebastian T. Ohlmann, Valeriia P. Kosheleva, Carlos M. Bustamante, Francesco Troisi, Angel Rubio, Heiko Appel

{"title":"Full minimal coupling Maxwell-TDDFT: an ab initio QED framework beyond the dipole approximation","authors":"Franco P. Bonafé, Esra Ilke Albar, Sebastian T. Ohlmann, Valeriia P. Kosheleva, Carlos M. Bustamante, Francesco Troisi, Angel Rubio, Heiko Appel","doi":"arxiv-2409.08959","DOIUrl":"https://doi.org/arxiv-2409.08959","url":null,"abstract":"We report the first ab initio, non-relativistic QED method that couples light\u0000and matter self-consistently beyond the electric dipole approximation and\u0000without multipolar truncations. This method is based on an extension of the\u0000known Maxwell-Pauli-Kohn-Sham approach for the use of a full minimal coupling\u0000Hamiltonian, where the space- and time-dependent vector potential is coupled to\u0000the matter system, and its back-reaction to the radiated fields is generated by\u0000the full current density. The implementation in the open-source Octopus code is\u0000designed for massively-parallel multiscale simulations considering different\u0000grid spacings for the Maxwell and matter subsystems. Here, we show the first\u0000applications of this framework to simulate renormalized Cherenkov radiation of\u0000an electronic wavepacket, magnetooptical effects with non-chiral light in\u0000non-chiral molecular systems, and renormalized plasmonic modes in a\u0000nanoplasmonic dimer. We show that in some cases the beyond-dipole effects can\u0000not be captured by a multipolar expansion Hamiltonian in length gauge. Finally,\u0000we discuss further opportunities enabled by the framework in the field of\u0000twisted light and orbital angular momentum, inelastic light scattering and\u0000strong field physics.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269072","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

Thickness-Dependent Polaron Crossover in Tellurene 碲中厚度相关的极龙交叉

arXiv - PHYS - Mesoscale and Nanoscale Physics Pub Date : 2024-09-13 DOI: arxiv-2409.08458

Kunyan Zhang, Chuliang Fu, Shelly Kelly, Liangbo Liang, Seoung-Hun Kang, Jing Jiang, Ruifang Zhang, Yixiu Wang, Gang Wan, Phum Siriviboon, Mina Yoon, Peide Ye, Wenzhuo Wu, Mingda Li, Shengxi Huang

{"title":"Thickness-Dependent Polaron Crossover in Tellurene","authors":"Kunyan Zhang, Chuliang Fu, Shelly Kelly, Liangbo Liang, Seoung-Hun Kang, Jing Jiang, Ruifang Zhang, Yixiu Wang, Gang Wan, Phum Siriviboon, Mina Yoon, Peide Ye, Wenzhuo Wu, Mingda Li, Shengxi Huang","doi":"arxiv-2409.08458","DOIUrl":"https://doi.org/arxiv-2409.08458","url":null,"abstract":"Polarons, quasiparticles arising from electron-phonon coupling, are crucial\u0000in understanding material properties such as high-temperature superconductivity\u0000and colossal magnetoresistance. However, scarce studies have been performed to\u0000investigate the formation of polarons in low-dimensional materials with phonon\u0000polarity and electronic structure transitions. In this work, we studied\u0000polarons of tellurene that are composed of chiral chains of tellurium atoms.\u0000The frequency and linewidth of the A1 phonon, which becomes increasingly polar\u0000for thinner tellurene, exhibit an abrupt change when the thickness of tellurene\u0000is below 10 nm. Meanwhile, the field effect mobility of tellurene drops rapidly\u0000as the thickness is smaller than 10 nm. These phonon and transport signatures,\u0000combined with the calculated phonon polarity and band structure, suggest a\u0000crossover from large polarons for bulk tellurium to small polarons for\u0000few-layer tellurene. Effective field theory considers the phonon\u0000renormalization in the strong coupling (small polaron) regime, and\u0000semi-quantitatively reproduces the observed phonon hardening and broadening\u0000effects in few-layer tellurene. This polaron crossover stems from the quasi-1D\u0000nature of tellurene where modulation of the interchain distance reduces the\u0000dielectric screening and promotes electron-phonon coupling. Our work provides\u0000valuable insights into the influence of polarons on phononic, electronic, and\u0000structural properties in low-dimensional materials.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268810","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

Gradient-based optimization of spintronic devices 基于梯度的自旋电子器件优化

arXiv - PHYS - Mesoscale and Nanoscale Physics Pub Date : 2024-09-13 DOI: arxiv-2409.09105

Yusuke Imai, Shuhong Liu, Nozomi Akashi, Kohei Nakajima

{"title":"Gradient-based optimization of spintronic devices","authors":"Yusuke Imai, Shuhong Liu, Nozomi Akashi, Kohei Nakajima","doi":"arxiv-2409.09105","DOIUrl":"https://doi.org/arxiv-2409.09105","url":null,"abstract":"The optimization of physical parameters serves various purposes, such as\u0000system identification and efficiency in developing devices. Spin-torque\u0000oscillators have been applied to neuromorphic computing experimentally and\u0000theoretically, but the optimization of their physical parameters has usually\u0000been done by grid search. In this paper, we propose a scheme to optimize the\u0000parameters of the dynamics of macrospin-type spin-torque oscillators using the\u0000gradient descent method with automatic differentiation. First, we prepared\u0000numerically created dynamics as teacher data and successfully tuned the\u0000parameters to reproduce the dynamics. This can be applied to obtain the\u0000correspondence between the simulation and experiment of the spin-torque\u0000oscillators. Next, we successfully solved the image recognition task with high\u0000accuracy by connecting the coupled system of spin-torque oscillators to the\u0000input and output layers and training all of them through gradient descent. This\u0000approach allowed us to estimate how to control the experimental setup and\u0000design the physical systems so that the task could be solved with a high\u0000accuracy using spin-torque oscillators.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":"54 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142253602","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

Role of material-dependent properties in THz field-derivative-torque-induced nonlinear magnetization dynamics 材料特性在太赫兹场衍生力矩诱导非线性磁化动力学中的作用

arXiv - PHYS - Mesoscale and Nanoscale Physics Pub Date : 2024-09-13 DOI: arxiv-2409.08541

Arpita Dutta, Pratyay Mukherjee, Swosti P. Sarangi, Somasree Bhattacharjee, Shovon Pal, Ritwik Mondal

{"title":"Role of material-dependent properties in THz field-derivative-torque-induced nonlinear magnetization dynamics","authors":"Arpita Dutta, Pratyay Mukherjee, Swosti P. Sarangi, Somasree Bhattacharjee, Shovon Pal, Ritwik Mondal","doi":"arxiv-2409.08541","DOIUrl":"https://doi.org/arxiv-2409.08541","url":null,"abstract":"The traditional Landau-Lifshitz-Gilbert (LLG) equation has often delineated\u0000the linear and nonlinear magnetization dynamics, even at ultrashort timescales\u0000e.g., femtoseconds. In contrast, several other non-relativistic and\u0000relativistic spin torques have been reported as an extension of the LLG spin\u0000dynamics. Here, we explore the contribution of the relativistic\u0000field-derivative torque (FDT) in the nonlinear THz magnetization dynamics\u0000response applied to ferrimagnets with high Gilbert damping and exchange magnon\u0000frequency. Our findings suggest that the FDT plays a significant role in\u0000magnetization dynamics in both linear and nonlinear regimes, bridging the gap\u0000between the traditional LLG spin dynamics and experimental observations. We\u0000find that the coherent THz magnon excitation amplitude is enhanced with the\u0000field-derivative torque. Furthermore, a phase shift in the magnon oscillation\u0000is induced by the FDT term. This phase shift is almost 90 for the\u0000antiferromagnet, while it is almost zero for the ferrimagnet under our\u0000investigation. Analyzing the dual THz excitation and their FDT, we find that\u0000the nonlinear signals can not be distinctly observed without the FDT terms.\u0000However, the inclusion of the FDT terms produces distinct nonlinear signals\u0000which matches extremely well with the previously reported experimental results.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142253612","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

Valley separation of photoexcited carriers in bilayer graphene 双层石墨烯中光激发载流子的谷分离

arXiv - PHYS - Mesoscale and Nanoscale Physics Pub Date : 2024-09-13 DOI: arxiv-2409.08807

T. J. Osborne, M. E. Portnoi, E. Mariani

{"title":"Valley separation of photoexcited carriers in bilayer graphene","authors":"T. J. Osborne, M. E. Portnoi, E. Mariani","doi":"arxiv-2409.08807","DOIUrl":"https://doi.org/arxiv-2409.08807","url":null,"abstract":"We derive the angular generation density of photoexcited carriers in gapless\u0000and gapped Bernal bilayer graphene. Exploiting the strong anisotropy of the\u0000band structure of bilayer graphene at low energies due to trigonal warping, we\u0000show that charge carriers belonging to different valleys propagate to different\u0000sides of the light spot upon photoexcitation. Importantly, in this low-energy\u0000regime, inter-valley electron-phonon scattering is suppressed, thereby\u0000protecting the valley index. This optically induced valley polarisation can be\u0000further enhanced via momentum alignment associated with linearly-polarised\u0000light. We then consider gapped bilayer graphene (for example with the gap\u0000induced by external top- and back-gates) and show that it exhibits\u0000valley-dependent optical selection rules with circularly-polarised light\u0000analogous to other gapped Dirac materials, such as transition metal\u0000dichalcogenides. Consequently, gapped bilayer graphene can be exploited to\u0000optically detect valley polarisation. Thus, we predict an optical valley Hall\u0000effect - the emission of two different circular polarisations from different\u0000sides of the light spot, upon linearly-polarised excitation. We also propose\u0000two realistic experimental setups in gapless and gapped bilayer graphene as a\u0000basis for novel optovalleytronic devices operating in the elusive terahertz\u0000regime.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142253610","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

Artificial moiré engineering for an ideal BHZ model 理想 BHZ 模型的人工摩尔纹工程

arXiv - PHYS - Mesoscale and Nanoscale Physics Pub Date : 2024-09-13 DOI: arxiv-2409.08540

Wangqian Miao, Arman Rashidi, Xi Dai

引用次数: 0

Berry phase effects on the transverse conductivity of Fermi surfaces and their detection via spin qubit noise magnetometry 贝里相位对费米表面横向电导率的影响及其通过自旋比特噪声磁强计的探测

arXiv - PHYS - Mesoscale and Nanoscale Physics Pub Date : 2024-09-13 DOI: arxiv-2409.09117

Mark Morgenthaler, Inti Sodemann Villadiego

引用次数: 0