Article
Materials Science, Multidisciplinary
Xinying Li, Ning Mao, Runhan Li, Ying Dai, Baibiao Huang, Chengwang Niu
Summary: In this study, a topological switch between normal insulator and AFM TI in two-dimensional NaMnBi quintuple layers is theoretically demonstrated. Using first-principles calculations, the researchers investigated the structure, stability, magnetism, and electronic properties, showing that the band gap and topology can be effectively tuned. The results not only expand the understanding of magnetic topological states but also propose potential applications in topological AFM spintronics.
JOURNAL OF MATERIALS CHEMISTRY C
(2021)
Article
Chemistry, Multidisciplinary
Guanyi Gao, Hairui Bao, Bao Zhao, Hao Huan, Zhongqin Yang
Summary: By using density-functional calculations and symmetry analysis, it was found that triply degenerate point (TDP) semimetals and Dirac semimetals exist in hydrogenated SnPb compounds. Additionally, other topological states like type-I, type-II, and Dirac semimetal states were also observed in these compounds, offering an ideal material platform for realizing topological semimetals and insulators in experiments.
Article
Chemistry, Physical
Wenbin Wu, Zeping Shi, Yuhan Du, Yuxiang Wang, Fang Qin, Xianghao Meng, Binglin Liu, Yuanji Ma, Zhongbo Yan, Mykhaylo Ozerov, Cheng Zhang, Hai-Zhou Lu, Junhao Chu, Xiang Yuan
Summary: The manuscript reports experimental observations of a Lifshitz transition in a topological insulator HfTe5 under a strong magnetic field, leading to the formation of one-dimensional Weyl modes in a three-dimensional material. By tracking the Landau level transitions, the study demonstrates that band inversion drives the crossing of zeroth Landau bands and the formation of a one-dimensional Weyl mode. This transition occurs at 21 T and moves the Weyl mode close to the Fermi level.
Article
Materials Science, Multidisciplinary
Rong Liu, Xiaodong Lv, Fengyu Li
Summary: Two planar 2D Dirac transition-metal nitrides, MN4 (M = Zn, Cd) monolayers, are reported using density functional theory (DFT) computations. These monolayers have unique structures, rich physics, and intriguing properties, exhibiting mechanical, dynamic, and thermal stabilities. They also feature anisotropic Dirac fermions with ultrahigh Fermi velocities, making them potentially useful in nanoelectronic devices.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2023)
Article
Physics, Multidisciplinary
Jun Zhang, Ye-Ping Jiang, Xu-Cun Ma, Qi-Kun Xue
Summary: In this study, we visualize the trapping of topological surface states in circular n-p junctions on the top surface of the seven-quintuple-layer three dimensional topological insulator Sb2Te3 epitaxial films. The trapped resonances show field-induced splittings between degenerate time-reversal-symmetric states, which can be attributed to Berry-phase switch. The successful trapping and observation of Berry-phase switch provide a rich platform for developing TI-based quantum devices.
PHYSICAL REVIEW LETTERS
(2022)
Article
Quantum Science & Technology
Takashi Mizokawa, Alexei Barinov, Viktor Kandyba, Alessio Giampietri, Ryoya Matsumoto, Yohei Okamoto, Kou Takubo, Koji Miyamoto, Taichi Okuda, Sunseng Pyon, Hiroyuki Ishii, Kazutaka Kudo, Minoru Nohara, Naurang L. Saini
Summary: Solids undergoing symmetry breaking phase transitions often form domains of low symmetry phases with different sizes and shapes. This article presents an interesting example of a layered dichalcogenide with a triangular lattice, where symmetry breaking of electronic charge/orbital is accompanied by the formation of striped domains and exotic surface states with peculiar spin textures. The study provides insights into the interplay between symmetry breaking, surface electronic structure, and the spin state.
ADVANCED QUANTUM TECHNOLOGIES
(2022)
Article
Chemistry, Physical
Cequn Li, Yi-Fan Zhao, Alexander Vera, Omri Lesser, Hemian Yi, Shalini Kumari, Zijie Yan, Chengye Dong, Timothy Bowen, Ke Wang, Haiying Wang, Jessica L. Thompson, Kenji Watanabe, Takashi Taniguchi, Danielle Reifsnyder Hickey, Yuval Oreg, Joshua A. Robinson, Cui-Zu Chang, Jun Zhu
Summary: We report on the growth and properties of high-quality (Bi,Sb)(2)Te-3/graphene/gallium heterostructures. Our synthetic approach enables atomically sharp layers at both hetero-interfaces, promoting proximity-induced superconductivity originating in the gallium film. A lithography-free, van der Waals tunnel junction is developed to perform transport tunnelling spectroscopy. We find a robust, proximity-induced superconducting gap formed in the Dirac surface states, and the presence of a single Abrikosov vortex manifesting in discrete conductance changes.
Article
Multidisciplinary Sciences
Maia G. Vergniory, Benjamin J. Wieder, Luis Elcoro, Stuart S. P. Parkin, Claudia Felser, B. Andrei Bernevig, Nicolas Regnault
Summary: Topological quantum chemistry and symmetry-based indicators have been used to search for materials with topological properties. This study implemented a publicly accessible catalog of stable and fragile topology in all bands at and away from the Fermi energy (E-F) in the Inorganic Crystal Structure Database. The calculations revealed the symmetry-indicated band topology of known nonmagnetic materials and led to the discovery of repeat-topological and supertopological materials.
Review
Multidisciplinary Sciences
B. Andrei Bernevig, Claudia Felser, Haim Beidenkopf
Summary: Magnetic topological materials have unique properties influenced by the topology of their electronic wave functions and magnetic spin configuration. In this review, we summarize the theoretical and experimental progress in this field and provide an outlook for future research.
Article
Multidisciplinary Sciences
Camiel van Efferen, Jan Berges, Joshua Hall, Erik van Loon, Stefan Kraus, Arne Schobert, Tobias Wekking, Felix Huttmann, Eline Plaar, Nico Rothenbach, Katharina Ollefs, Lucas Machado Arruda, Nick Brookes, Gunnar Schoenhoff, Kurt Kummer, Heiko Wende, Tim Wehling, Thomas Michely
Summary: In monolayer VS2, a CDW gap resides in the unoccupied states but induces a topological metal-metal transition at the Fermi level. Additionally, the non-linear coupling of transverse and longitudinal phonons is essential for the formation of the CDW.
NATURE COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Manato Fujimoto, Mikito Koshino
Summary: This study investigates the edge states of twisted bilayer graphene and their topological origin, revealing a special relationship with the moire pattern and the sliding Chern number. The emergence of these moire edge states is linked with topological charge pumping caused by relative interlayer sliding, demonstrating a bulk-edge correspondence inherent in moire bilayer systems.
Article
Materials Science, Multidisciplinary
Santosh Kumar Radha, Walter R. L. Lambrecht
Summary: Annihilating a pair of Dirac fermions leads to a topological transition from the critical semimetallic phase to an obstructed atomic limit insulator phase, instead of a trivial insulator phase. This transition is attributed to branch cuts in the phase of wave functions, resulting in nontrivial Zak phase along certain directions.
Article
Materials Science, Multidisciplinary
F. Crasto de Lima, B. Focassio, R. H. Miwa, A. Fazzio
Summary: Transition metal dichalcogenides have attracted significant attention for their applications and fundamental properties. In this study, we focus on single-layer PtSe2 and its derivative Pt2HgSe3, which exhibits topological insulator behavior. By combining ab-initio calculations and defect wave function percolation model, we investigate the stability and topological transition of Pt(HgxSe1-x)(2) alloys as a function of alloy concentration and Hg distribution. Our findings demonstrate the dependence of the topological phase on alloy concentration and its robustness with respect to the distribution. Furthermore, we estimate the threshold alloy concentration for topological transition to be as low as 9%.
Article
Multidisciplinary Sciences
J. A. Crosse, Pilkyung Moon
Summary: Study of a double moiré superlattice reveals 0 to 4 lattice configurations depending on mismatch, and uncovers a resonant interaction that hybridizes twelve degenerate Bloch states of monolayer graphene, exhibiting trigonal quasicrystalline order at energies closer to neutrality point.
SCIENTIFIC REPORTS
(2021)
Article
Materials Science, Multidisciplinary
Rebecca Engelke, Hyobin Yoo, Stephen Carr, Kevin Xu, Paul Cazeaux, Richard Allen, Andres Mier Valdivia, Mitchell Luskin, Efthimios Kaxiras, Minhyong Kim, Jung Hoon Han, Philip Kim
Summary: In this study, practical and analytical tools are developed to understand the nano-scale moire superlattice structure, which can be applied to other lattice distortions and lattice types. It is found that at large enough moire lengths, all moire systems relax into commensurated 2D domains separated by networks of dislocation lines. These dislocation line networks can be considered as vortexlike topological defects.
Article
Optics
Bin Li, Xuming Pang, Jianxin Jiang, Danyang Zhao, Jianxin Zhou, Gang Liu
Summary: In this paper, TiN/TiC-Ni/Mo-Y2O3 cermet-based single-layer nano-composite solar spectrum selective absorption coatings were prepared on 316L stainless steel matrix by laser cladding. The coating with 3 wt.% Y2O3 addition exhibited the best optical performance, and after heat treatment at 800 degrees C for 24 h, the absorptivity and emissivity of the coating retained 81.0% and 2.9%, respectively, which was better than most single-layer solar selective absorption coating. Moreover, the corrosion resistance and wear resistance of the coating were significantly improved, indicating the potential of cermet-based coatings for the development of solar selective absorption coatings.
APPLIED PHYSICS B-LASERS AND OPTICS
(2023)
Article
Chemistry, Inorganic & Nuclear
Fengfeng Chi, Zhangchao Ji, Qian Liu, Bin Jiang, Bing Wang, Jie Cheng, Bin Li, Shengli Liu, Xiantao Wei
DALTON TRANSACTIONS
(2023)
Article
Engineering, Electrical & Electronic
Bin Li, Yulong Zou, Jia Zhu, Chenguang Shi, Hong Zeng
Summary: In this paper, the secrecy outage probability of a relay aided multiuser network is analyzed in the presence of an eavesdropper and co-channel interference (CCI). Two relay aided multiuser scheduling (RMS) schemes are proposed to improve the secrecy outage performance, and their closed-form expressions are derived. Numerical results show that the proposed RMS schemes outperform the baseline round-robin scheduling (RRRS) scheme, with the full CSI based RMS achieving the best secrecy outage performance. It is also found that the number of users has a significant impact on the secrecy outage performance of the proposed schemes, while the RRRS scheme remains unchanged.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Ro-Ya Liu, Angus Huang, Raman Sankar, Joseph Andrew Hlevyack, Chih-Chuan Su, Shih-Chang Weng, Meng-Kai Lin, Peng Chen, Cheng-Maw Cheng, Jonathan D. Denlinger, Sung-Kwan Mo, Alexei V. Fedorov, Chia-Seng Chang, Horng-Tay Jeng, Tien-Ming Chuang, Tai-Chang Chiang
Summary: This study presents spectroscopic signatures of a predicted topological hourglass semimetal phase in Nb3SiTe6 through angle-resolved photoemission. The results show the existence of linear band crossings and nodal loops, originating from nontrivial Berry phase and predicted glide quantum spin Hall effect. The observation of saddle-like Fermi surface and in situ alkali-metal doping also reveal other band crossings and correlated parabolic bands with accidental nodal loop states.
Article
Nanoscience & Nanotechnology
Christy Roshini Paul Inbaraj, Roshan Jesus Mathew, Raman Sankar, Hsia Yu Lin, Nian-Xiu Li, Yit-Tsong Chen, Yang-Fang Chen
Summary: This study demonstrates the simultaneous visible and infrared photodetection using a 2D heterostructure and a dielectric polymer. The combination of the ferroelectric and pyroelectric effects enhances the photoresponsivity and improves the detection performance. This approach holds great potential for the design of advanced optoelectronic devices.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Engineering, Electrical & Electronic
Shuying Lin, Yulong Zou, Bin Li, Tong Wu
Summary: In this paper, the authors investigate the physical layer security of a reconfigurable intelligent surface (RIS)-aided wireless network with multiple users, a RIS, a multi-antenna base station (BS) and an eavesdropper. Different jamming schemes are proposed to enhance the security of the multiuser communications, and their performance is analyzed in terms of outage probability and intercept probability. The results show that the proposed schemes outperform the baseline scheme and can be further optimized through power allocation.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Chuanjun Wang, Wei Xiang, Ke Hu, Bin Li
Summary: In this study, a dynamic data preprocessing method is proposed for parameter identification in power distribution networks (PDNs) to obtain more accurate results. This method considers the similarities of feeder data in terms of spatial relationship and statistical theory, and achieves a dynamic aggregation process for new data. The experimental results show that the identification results with this preprocessing method can improve accuracy by up to 5.3%.
IET COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Federico Mazzola, Yanxue Zhang, Natalia Olszowska, Marcin Rosmus, Gianluca D'Olimpio, Marian Cosmin Istrate, Grazia Giuseppina Politano, Ivana Vobornik, Raman Sankar, Corneliu Ghica, Junfeng Gao, Antonio Politano
Summary: Nonmagnetic chiral crystals are a new type of materials that possess Kramers-Weyl Fermions due to the combination of structural chirality, spin-orbit coupling, and time-reversal symmetry. These materials exhibit unique Fermi surfaces with spin-orbit coupling-induced Chern gaps, leading to exotic transport and optical properties. This study investigates the electronic structure and transport properties of CdAs2, a recently discovered chiral material, using angle-resolved photoelectron spectroscopy and density functional theory. The results suggest that CdAs2 is a promising candidate for novel topological properties and provide valuable insights for the development of spintronic and optical devices based on chiral charges and nontrivial Chern numbers.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Xiaofeng Hao, Yan Bai, Bin Li, Zhixiang Shi
Summary: We conducted first-principles calculations to investigate the structural and electronic properties of chromium nitrides under high pressure. By predicting crystal structures, we identified novel chromium nitrogen compounds and pressure-induced phase transitions in the Cr-N system up to 200 GPa. The dynamic stable compounds, CrN2, CrN6, and Cr2N3, were examined through electronic and phononic calculations. This study provides a theoretical basis for understanding the phase transitions of Cr-N compounds under different pressures, offers directions for future research on Cr-N systems, and may inspire the synthesis of superhard and high energy density materials.
Article
Nanoscience & Nanotechnology
Roshan Jesus Mathew, Kai-Hsiang Cheng, Christy Roshini Paul Inbaraj, Raman Sankar, Xuan P. A. Gao, Yit-Tsong Chen
Summary: In this study, novel anti-ambipolar transistors (AATs) with gate tunable rectifiers were investigated for their optoelectronic applications in cryogenic conditions. A p-SnS/n-MoSe2 cryo-phototransistor was presented, exhibiting unique anti-ambipolar characteristics and cryogenic-enhanced optoelectronic performance. The cryo-phototransistor showed a sharp and highly symmetric anti-ambipolar transfer curve at 77 K, with high responsivity and detectivity in the spectral range of 250-900 nm.
ADVANCED ELECTRONIC MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Chih-Ying Huang, Hung-Min Lin, Chun-Hao Chiang, Hsin-An Chen, Ting-Ran Liu, S. K. Deepak Vishnu, Jau-Wern Chiou, Raman Sankar, Huang-Ming Tsai, Way-Faung Pong, Chun-Wei Chen
Summary: A significant enhancement of oxygen evolution reaction (OER) performance is achieved by controlling the spin-exchange interaction and spin-selected electron transfer of 2D CoxFe1-xPS3 (x = 0-0.45) van der Waals (vdW) single crystals through Co doping. The Co-doped FePS3 crystal shows the emergence of interatomic ferromagnetism due to doping-mediated magnetic exchange interactions, leading to improved spin-selected electron transfer efficiencies compared to the pristine FePS3 crystal. The correlation between spin-exchange interactions and spin-selected electron transfers with superior OER performance is further revealed by experimental measurements and theoretical simulations.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Physics, Condensed Matter
Bin Li, Yeqian Yang, Yuxiang Fan, Cong Zhu, Shengli Liu, Zhixiang Shi
Summary: Pd3P2S8 is a semiconductor containing Kagome lattices with various physical phenomena. Structural searches revealed four phases, two in the P3?m1 space group (P3?m1 -1 and P3?m1 -2) and two in the C2/m space group (C2/m -1 and C2/m -2), with all but C2/m -2 phase being dynamically stable. Electron-phonon calculations confirmed that both phases exhibit superconductivity, with the P3?m1 -1 phase undergoing a semiconductor-to-superconductor transition and achieving a maximum Tc of 9.13 K at 70 GPa. This study expands the options for studying superconductivity in materials with Kagome lattices.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Chemistry, Multidisciplinary
Chih-Ying Huang, Hung-Min Lin, Chun-Hao Chiang, Hsin-An Chen, Ting-Ran Liu, Deepak S. K. Vishnu, Jau-Wern Chiou, Raman Sankar, Huang-Ming Tsai, Way-Faung Pong, Chun-Wei Chen
Summary: This study demonstrates a significant enhancement of oxygen evolution reaction (OER) performance by controlling the spin-exchange interaction and spin-selected electron transfer of 2D CoxFe1-xPS3 van der Waals (vdW) single crystals through Cobalt (Co) doping. The Co-doped FePS3 crystals exhibit interatomic ferromagnetism, allowing the formation of efficient spin-selective electron transfer channels compared to the pristine FePS3. The correlation between spin-exchange interactions and spin-selected electron transfers in Co-doped FePS3 crystals with superior OER performance is revealed.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Hemanth Kumar Bangolla, Muhammad Yusuf Fakhri, Ching-Hsuan Lin, Cheng-Maw Cheng, Yi-Hung Lu, Tsu-Yi Fu, Pushpa Selvarasu, Rajesh Kumar Ulaganathan, Raman Sankar, Ruei-San Chen
Summary: Two interesting electronic transport properties, in-plane anisotropy and nonhomogeneous carrier distribution, are observed in ReS2 nanoflakes. The presence of surface electron accumulation indicates a surface-dominant 2D transport.