Chinese Physics Letters最新文献_第8页

Optical Nonlinearity of Violet Phosphorus and Applications in Fiber Laser 紫磷的光学非线性及其在光纤激光器中的应用

IF 3.5 2区物理与天体物理

Chinese Physics Letters Pub Date : 2023-12-13 DOI: 10.1088/0256-307x/41/1/014202

Hui-ran Yang, Meng-ting Qi, Xu-peng Li, Ze Xue, Chen-hao Lu, Jia-wei Cheng, Dong-dong Han, Lu Li

引用次数: 0

Real-time observation of the instantaneous ac Stark shift of vacuum using a zeptosecond laser pulse 使用zeptosecond激光脉冲实时观测真空的瞬时交流斯塔克偏移

IF 3.5 2区物理与天体物理

Chinese Physics Letters Pub Date : 2023-12-13 DOI: 10.1088/0256-307x/41/1/014201

Dandan Su, Miao Jiang

引用次数: 0

VASP2KP: $ kcdot p $ models and Landé $g$-factors from $ab-initio$ calculations VASP2KP: $ kcdot p $ 模型和来自 $ab-initio$ 计算的 Landé $g$ 因子

IF 3.5 2区物理与天体物理

Chinese Physics Letters Pub Date : 2023-12-06 DOI: 10.1088/0256-307x/40/12/127101

Sheng Zhang, Haohao Sheng, Zhi-Da Song, Chenhao Liang, Yi Jiang, Song Sun, Quansheng Wu, Hongming Weng, Zhongyuan Fang, Xi Dai, Zhijun Wang

{"title":"VASP2KP: $ kcdot p $ models and Landé $g$-factors from $ab-initio$ calculations","authors":"Sheng Zhang, Haohao Sheng, Zhi-Da Song, Chenhao Liang, Yi Jiang, Song Sun, Quansheng Wu, Hongming Weng, Zhongyuan Fang, Xi Dai, Zhijun Wang","doi":"10.1088/0256-307x/40/12/127101","DOIUrl":"https://doi.org/10.1088/0256-307x/40/12/127101","url":null,"abstract":"\u0000 The $kcdot p$ method is significant in condensed matter physics for the compact and analytical Hamiltonian.In the presence of magnetic field, it is described by effective Zeeman's coupling Hamiltonian with Landé $g$-factors. Here, we develop an $pen-source$ package VASP2KP (including two parts: vasp2mat and mat2kp) to compute $kcdot p$ parameters and Landé $g$-factors directly from the wavefunctions provided by the density functional theory (DFT) as implemented in Vienna $ab initio$ Simulation Package (VASP). First, we develop a VASP patch vasp2mat to compute matrix representations of the generalized momentum operator $boldsymbol{hat{pi}}=boldsymbol{hat{p}}+frac{1}{2mc^2}left(boldsymbol{hat{s}}timesnabla V(boldsymbol{r})right) $, spin operator $boldsymbol{hat{s}}$, time reversal operator $hat{T}$ and crystalline symmetry operators $hat{R}$ on the DFT wavefunctions. Second, we develop a python code mat2kp to obtain the unitary transformation $U$ that rotates the degenerate DFT basis towards the standard basis, and then automatically compute the $kcdot p$ parameters and $g$-factors. The theory and the methodology behind VASP2KP are described in detail. The matrix elements of the operators are derived comprehensively and computed correctly within the Projector Augmented Wave method. We apply this package to some materials, $e.g$.Bi$_2$Se$_3$, Na$_3$Bi, Te, InAs and 1H-TMD monolayers. The obtained effective model's dispersions are in good agreement with the DFT data around the specific wave vector, and the $g$-factors are consistent with experimental data. The VASP2KP package is available at https://github.com/zjwang11/VASP2KP.","PeriodicalId":10344,"journal":{"name":"Chinese Physics Letters","volume":"58 16","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138597435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of Age on Speech Perception in Noise Abilities Across Different Stimulus. 年龄对不同刺激条件下语音感知能力的影响。

IF 3.5 2区物理与天体物理

Chinese Physics Letters Pub Date : 2023-12-01 Epub Date: 2023-07-18 DOI: 10.1007/s12070-023-04084-7

Banumathi, Supriya Mathew, Sandeep Kumar, Chandni Jain

{"title":"Effect of Age on Speech Perception in Noise Abilities Across Different Stimulus.","authors":"Banumathi, Supriya Mathew, Sandeep Kumar, Chandni Jain","doi":"10.1007/s12070-023-04084-7","DOIUrl":"10.1007/s12070-023-04084-7","url":null,"abstract":"Various factors influence speech perception in noise (SPIN): age, hearing loss, cognition, background noise, stimulus redundancy, type of stimulus used, and signal-to-noise ratio. The effect of age on SPIN with different stimuli is yet to be validated in the literature. This study aims to study the effect of age on SPIN results across different stimuli. The study is a cross-sectional study with ninety participants with normal hearing ability. All participants in the study were equally divided into three groups: the children's group aged 8 to 12 years, the adult group aged 18 to 30, and the older adult group aged 55 to 72 years. Speech perception in the background of Kannada speech babble was assessed across three stimuli: monosyllables (CV), phonemically balanced Kannada words, and Kannada sentences. The stimulus was presented at 60 dBSPL binaurally through a calibrated headphone at 0 dB SNR. The result indicated a significant main effect of age on SPIN across syllables, words, and sentences. Further, Mann-Whitney test results revealed a statistically significant difference between the SPIN scores of children and adults for syllables, words, and sentences. Also, a statistical difference was noted in SPIN scores between adults and older adults for syllables, words, and sentences. However, statistical differences between children and older adults were seen only for syllables. The trend showed that the SPIN scores for syllables, words, and sentences improve from childhood to adulthood, while scores deteriorate from the adult to older adult group. A similar trend was seen for all three stimulus types. However, the reduction in the SPIN score using syllables in the older adult group was more noticeable than words and sentences. It can be concluded that there is an effect of age on SPIN abilities across different stimuli. It highlights the importance of age-appropriate SPIN normative for various stimuli.","PeriodicalId":10344,"journal":{"name":"Chinese Physics Letters","volume":"32 1","pages":"3718-3724"},"PeriodicalIF":3.5,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10646145/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82534060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Performance Improvement of a Direct Carbon Fuel Cell through an Irreversible Vacuum Thermionic Generator 通过不可逆真空热离子发生器提高直接碳燃料电池的性能

IF 3.5 2区物理与天体物理

Chinese Physics Letters Pub Date : 2023-12-01 DOI: 10.1088/0256-307x/40/12/128201

Yuan Wang, Shanhe Su

引用次数: 0

Ultrafast Fiber Laser Based on Tungsten Sulphoselenide Materials 基于磺化硒化钨材料的超快光纤激光器

IF 3.5 2区物理与天体物理

Chinese Physics Letters Pub Date : 2023-12-01 DOI: 10.1088/0256-307x/40/12/124202

Xiao-Chuan Meng, Lu Li, Nai-Zhang Sun, Ze Xue, Qi Liu, Han Ye, Wen-Jun Liu

{"title":"Ultrafast Fiber Laser Based on Tungsten Sulphoselenide Materials","authors":"Xiao-Chuan Meng, Lu Li, Nai-Zhang Sun, Ze Xue, Qi Liu, Han Ye, Wen-Jun Liu","doi":"10.1088/0256-307x/40/12/124202","DOIUrl":"https://doi.org/10.1088/0256-307x/40/12/124202","url":null,"abstract":"Tungsten sulphoselenide (WSSe) alloys, belonging to the transition metal dichalcogenide family, have attracted significant interest in the area of optoelectronics because of their unique optical and electronic properties. However, there has been a dearth of sufficient research on the saturable absorption features and ultrafast lasers applications. Herein, we fabricated a WSSe-microfiber saturable absorber (SA) based on WSSe nanosheets prepared by liquid exfoliation technique. The SA provided a saturation intensity of a modulation depth of 27.95% and a nonsaturable loss of 21.34%. To investigate the potential applications of WSSe in ultrafast photonics, the prepared WSSe-microfiber was incorporated into an Er-doped fiber laser ring cavity. The results demonstrated that the WSSe-based SA successfully generated mode-locking laser pulses with a remarkably short pulse width of 231 fs. Furthermore, the output power of this ultrafast fiber laser reached an impressive value of 15.68 mW. These findings provide valuable views into the unique features of WSSe alloys in the areas of ultrafast optics and develop recipes for SA in ultrafast fiber lasers.","PeriodicalId":10344,"journal":{"name":"Chinese Physics Letters","volume":"13 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139055181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Phonon thermal transport at the interfaces of graphene/vertically aligned carbon nanotubes /hexagonal boron nitride sandwich heterostructure 石墨烯/垂直排列碳纳米管/六方氮化硼三明治异质结构界面的声子热传输

IF 3.5 2区物理与天体物理

Chinese Physics Letters Pub Date : 2023-12-01 DOI: 10.1088/0256-307x/41/1/016302

Menglin Li, M. A. Shakoori, Ruipeng Wang, Haipeng Li

{"title":"Phonon thermal transport at the interfaces of graphene/vertically aligned carbon nanotubes /hexagonal boron nitride sandwich heterostructure","authors":"Menglin Li, M. A. Shakoori, Ruipeng Wang, Haipeng Li","doi":"10.1088/0256-307x/41/1/016302","DOIUrl":"https://doi.org/10.1088/0256-307x/41/1/016302","url":null,"abstract":"\u0000 In this paper, molecular dynamics simulation is used to calculate the interfacial thermal resistance (ITR) of the graphene/carbon nanotubes/hexagonal boron nitride (Gr/CNTs/hBN) sandwich heterostructure, of which vertically aligned carbon nanotube (VACNT) arrays is covalently bonded to graphene and hexagonal boron nitride layers. We found that the ITR of the Gr/VACNT/hBN sandwich heterostructure is 1-2 orders of magnitude smaller than the ITR of the Gr/hBN Van der Waals heterostructure with the same plane size. It is observed that the covalent bonding effectively enhances the phonon coupling between Gr and hBN layers, resulting in an increase in the overlap factor of phonon density of state between Gr and hBN, thus reducing the ITR of Gr and hBN. In addition, the chirality, size (diameter and length) and packing density of sandwich-layer VACNT have an important influence on the ITR of the heterostructure. Under the same diameter and length of CNT, the ITR of the sandwich heterostructure with armchair-shaped VACNT is higher than that of the sandwich heterostructure with zigzag-shaped VACNT, due to the different chemical bonding of chiral CNT with Gr and hBN. When the armchairshaped CNT diameter increases or the length decreases, the ITR of the sandwich heterostructure tends to decrease. Moreover, the increase in the packing density of VACNT has also led to a continuous decrease in the ITR of the sandwich heterostructure, attributed to the extremely high intrinsic thermal conductivity of CNT and the increase of out-ofplane heat transfer channels. This work will help to understand the mechanism for ITR for multi-layer vertical heterostructures, and provide theoretical guidance for a new strategy to regulate the inter-layer thermal resistance of heterostructures by optimizing the design of sandwich layer thermal interface materials.","PeriodicalId":10344,"journal":{"name":"Chinese Physics Letters","volume":"33 S123","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138623219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Chiral Dirac Fermion in a Collinear Antiferromagnet 共线反铁磁体中的手性狄拉克费米子

IF 3.5 2区物理与天体物理

Chinese Physics Letters Pub Date : 2023-12-01 DOI: 10.1088/0256-307x/40/12/126101

Ao Zhang, Ke Deng, Jieming Sheng, Pengfei Liu, Shiv Kumar, Kenya Shimada, Zhicheng Jiang, Zhengtai Liu, Dawei Shen, Jiayu Li, Jun Ren, Le Wang, Liang Zhou, Yoshihisa Ishikawa, Takashi Ohhara, Qiang Zhang, Garry McIntyre, Dehong Yu, Enke Liu, Liusuo Wu, Chaoyu Chen, Qihang Liu

{"title":"Chiral Dirac Fermion in a Collinear Antiferromagnet","authors":"Ao Zhang, Ke Deng, Jieming Sheng, Pengfei Liu, Shiv Kumar, Kenya Shimada, Zhicheng Jiang, Zhengtai Liu, Dawei Shen, Jiayu Li, Jun Ren, Le Wang, Liang Zhou, Yoshihisa Ishikawa, Takashi Ohhara, Qiang Zhang, Garry McIntyre, Dehong Yu, Enke Liu, Liusuo Wu, Chaoyu Chen, Qihang Liu","doi":"10.1088/0256-307x/40/12/126101","DOIUrl":"https://doi.org/10.1088/0256-307x/40/12/126101","url":null,"abstract":"In a Dirac semimetal, the massless Dirac fermion has zero chirality, leading to surface states connected adiabatically to a topologically trivial surface state as well as vanishing anomalous Hall effect. Recently, it is predicted that in the nonrelativistic limit of certain collinear antiferromagnets, there exists a type of chiral “Dirac-like” fermion, whose dispersion manifests four-fold degenerate crossing points formed by spin-degenerate linear bands, with topologically protected Fermi arcs. Such an unconventional chiral fermion, protected by a hidden <italic toggle=\"yes\">SU</italic>(2) symmetry in the hierarchy of an enhanced crystallographic group, namely spin space group, is not experimentally verified yet. Here, by angle-resolved photoemission spectroscopy measurements, we reveal the surface origin of the electron pocket at the Fermi surface in collinear antiferromagnet CoNb3S6. Combining with neutron diffraction and first-principles calculations, we suggest a multidomain collinear antiferromagnetic configuration, rendering the the existence of the Fermi-arc surface states induced by chiral Dirac-like fermions. Our work provides spectral evidence of the chiral Dirac-like fermion caused by particular spin symmetry in CoNb3S6, paving an avenue for exploring new emergent phenomena in antiferromagnets with unconventional quasiparticle excitations.","PeriodicalId":10344,"journal":{"name":"Chinese Physics Letters","volume":"87 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139055451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Simulation Prediction of Heat Transport with Machine Learning in Tokamak Plasmas 利用机器学习对托卡马克等离子体中的热传输进行模拟预测

IF 3.5 2区物理与天体物理

Chinese Physics Letters Pub Date : 2023-12-01 DOI: 10.1088/0256-307x/40/12/125201

Hui Li, Yan-Lin Fu, Ji-Quan Li, Zheng-Xiong Wang

引用次数: 0

Multi-Pseudo Peakons in the b-Family Fifth-Order Camassa–Holm Model b 族五阶卡马萨-霍尔姆模型中的多伪峰子

IF 3.5 2区物理与天体物理

Chinese Physics Letters Pub Date : 2023-12-01 DOI: 10.1088/0256-307x/40/12/120202

Dinghao Zhu, Xiaodong Zhu

引用次数: 0