Article
Chemistry, Multidisciplinary
Yi-Ying Sung, Harmina Vejayan, Christopher J. Baddeley, Neville V. Richardson, Federico Grillo, Renald Schaub
Summary: On-surface synthesis with designer precursor molecules is an effective method for preparing graphene nanoribbons (GNRs) with tunable electronic properties. The band gap of GNRs doped with heteroatoms remains unchanged, but hydrogenation can engineer a tunable band gap. Surface-confined hydrogenation studies on 7-armchair GNRs grown on Au(111) surfaces reveal a self-limited hydrogenation process. The electronic properties of the GNR/Au(111) system can be modified by edge and basal-plane hydrogenation, and a mechanism for the hydrogenation process is proposed.
Article
Chemistry, Multidisciplinary
Xinzuo Sun, Yan Chen, Dongyang Zhao, Takashi Taniguchi, Kenji Watanabe, Jianlu Wang, Jiamin Xue
Summary: This study demonstrates the significant modulation of the band structure of few-layer MoS2 using a ferroelectric P(VDF-TrFE) gate. The fully polarized P(VDF-TrFE) gate creates an electric field of up to 0.62 V/nm through the MoS2 layers, which greatly affects the band structure. The experimental results show a strong band bending effect and an enlarged energy separation between quantum-well subbands. This study intuitively showcases the potential of ferroelectric gates in manipulating the band structure of 2D materials.
Article
Multidisciplinary Sciences
Alexander Kerelsky, Carmen Rubio-Verdu, Lede Xian, Dante M. Kennes, Dorri Halbertal, Nathan Finney, Larry Song, Simon Turkel, Lei Wang, Kenji Watanabe, Takashi Taniguchi, James Hone, Cory Dean, Dmitri N. Basov, Angel Rubio, Abhay N. Pasupathy
Summary: This study demonstrates the formation of emergent correlated phases in multilayer rhombohedral graphene without the need for twisted van der Waals layers. The study shows that two layers of bilayer graphene twisted by a tiny angle can host large regions of uniform rhombohedral four-layer graphene with a sharp van Hove singularity. Furthermore, the study suggests that the broken symmetry state in ABCA graphene could be attributed to a charge-transfer excitonic insulator or a ferrimagnet.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Chemistry, Physical
V. Carnevali, A. Sala, P. Biasin, M. Panighel, G. Comelli, M. Peressi, C. Africh
Summary: The electronic properties of graphene can be modified by local interaction with a metal substrate. This article proposes a reliable method of evaluating the interaction between graphene and substrate by testing the tunneling current. This method expands the capabilities of standard STM systems for studying graphene/substrate complexes.
Article
Chemistry, Multidisciplinary
Andrey K. Gatin, Sergey Y. Sarvadii, Nadezhda V. Dokhlikova, Vasiliy A. Kharitonov, Sergey A. Ozerin, Boris R. Shub, Maxim V. Grishin
Summary: The oxidation of Ni nanoparticles supported on highly oriented pyrolytic graphite under low exposure to oxygen was studied. It was found that charge transfer effects at the Ni-C interface influenced the surface activity of the nanoparticles. O-2 dissociation and Ni oxidation occurred only at the top of the nanoparticle.
Review
Chemistry, Multidisciplinary
Wenbing Peng, Haolin Wang, Hui Lu, Lei Yin, Yue Wang, Bruno Grandidier, Deren Yang, Xiaodong Pi
Summary: Understanding the band alignment, interface states, interface coupling, and carrier transport properties of semiconductor heterojunctions (SHs) is crucial for designing and fabricating semiconductor structures and devices. STM and STS have played significant roles in studying the properties of SHs, such as spatial structures and electronic band structures, to propose mechanisms for carrier transport.
Article
Physics, Multidisciplinary
M. Omidian, J. Brand, N. Neel, S. Crampin, J. Kroeger
Summary: Epitaxially grown Fe nanostructures on Pb(111) were studied using low-temperature scanning tunneling microscopy and spectroscopy. The Fe assemblies were categorized into two groups based on their electronic behavior near the Fermi energy. One group exhibited a metallic behavior with a wide energy gap of 0.7 eV that remained temperature-independent. These Fe islands lacked the superconductivity proximity effect in their interior. The other group displayed a metallic behavior at the Fermi level, with the substrate superconducting phase locally entering these islands, evidenced by sharp resonance at the Fermi energy indicating possible Andreev reflection at the magnet-superconductor interface.
NEW JOURNAL OF PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Qilong Wu, Xiaoshuai Fu, Ke Yang, Hongyu Wu, Li Liu, Li Zhang, Yuan Tian, Long-Jing Yin, Wei-Qing Huang, Wen Zhang, Ping Kwan Johnny Wong, Lijie Zhang, Andrew T. S. Wee, Zhihui Qin
Summary: This study demonstrates a practical approach to producing highly crystalline monolayer MoSe2 using high-temperature-annealed Au foil as a weakly interacting substrate for atmospheric pressure chemical vapor deposition. The low-temperature scanning tunneling microscopy/spectroscopy measurements reveal a honeycomb structure of MoSe2 with a quasi-particle bandgap of 1.96 eV. The weak coupling between the Au(100) surface and MoSe2 is critical for easy transfer of monolayers to another host substrate.
Article
Chemistry, Multidisciplinary
Meng-Kai Lin, Guan-Hao Chen, Ciao-Lin Ho, Wei-Chen Chueh, Joseph Andrew Hlevyack, Chia-Nung Kuo, Tsu-Yi Fu, Juhn-Jong Lin, Chin Shan Lue, Wen-Hao Chang, Noriaki Takagi, Ryuichi Arafune, Tai-Chang Chiang, Chun-Liang Lin
Summary: Monolayer transition metal dichalcogenides show tunability in electronic properties, with bandgap modulation possible through control of tunneling current. Monolayer PtTe2 exhibits a reversible semiconductor-to-metal transition at moderate tunneling current, attributed to its surface electronic structure coupling with the tunneling tip.
Article
Chemistry, Multidisciplinary
Xinzuo Sun, Yan Chen, Zhiwei Li, Yu Han, Qin Zhou, Binbin Wang, Takashi Taniguchi, Kenji Watanabe, Aidi Zhao, Jianlu Wang, Yuan Liu, Jiamin Xue
Summary: Researchers successfully visualized the nanometer-scale band profiles of MoS2/WSe2 heterostructure devices using contact-mode scanning tunneling spectroscopy. Due to strong inter- and intralayer charge transfer, the MoS2 layer changes from n-type to p-type, leading to the development of gate-tunable p-n and p-p(+) junctions in the devices. Highly conductive edges were also discovered, which could significantly impact device properties.
Article
Chemistry, Multidisciplinary
Qiucheng Li, Xiaolong Liu, Eden B. Aklile, Shaowei Li, Mark C. Hersam
Summary: The study reports the self-assembly of mixed-dimensional lateral heterostructures consisting of 2D metallic borophene and 1D semiconducting armchair-oriented graphene nanoribbons (aGNRs). The systematic study and refinement of on-surface polymerization process from monomers to organometallic intermediates to demetallization result in borophene/aGNR lateral heterojunctions with structurally and electronically abrupt interfaces, providing insight for precise nanoelectronics.
Article
Chemistry, Multidisciplinary
Qilong Wu, Meysam Bagheri Tagani, Lijie Zhang, Jing Wang, Yu Xia, Li Zhang, Sheng-Yi Xie, Yuan Tian, Long-Jing Yin, Wen Zhang, Alexander N. Rudenko, Andrew T. S. Wee, Ping Kwan Johnny Wong, Zhihui Qin
Summary: In this study, we demonstrate the electronic tuning ability at the WSe2/Au interface using twist engineering. By changing the twist angle, we are able to modulate the carrier doping in WSe2 from intrinsic p-type to n-type. We further achieve an n-p-n-type WSe2 homojunction by achieving a strong coupling interface. Additionally, we find that germanium intercalation can recover the intrinsic doping of WSe2. Our findings reveal the influence of twist angle and intercalation on interface doping.
Article
Materials Science, Multidisciplinary
Estelle Mazaleyrat, Sergio Vlaic, Alexandre Artaud, Laurence Magaud, Thomas Vincent, Ana Cristina Gomez-Herrero, Simone Lisi, Priyank Singh, Nedjma Bendiab, Valerie Guisset, Philippe David, Stephane Pons, Dimitri Roditchev, Claude Chapelier, Johann Coraux
Summary: This study introduces a strategy to induce superconductivity in epitaxial graphene via a remote proximity effect using an intercalated gold layer. The experiments demonstrate a weak interaction between graphene and gold, enabling superconductivity, and reveal the main shortcoming of the intercalation approach is the creation of a high density of point defects in graphene.
Article
Nanoscience & Nanotechnology
Pierre Capiod, Maaike van der Sluijs, Jeroen de Boer, Christophe Delerue, Ingmar Swart, Daniel Vanmaekelbergh
Summary: The study utilized rock-salt lead selenide nanocrystals as building blocks for large scale square superlattices, revealing that the electronic structure is still influenced by disorder and variability despite crystalline connections.
Scanning Tunneling Spectroscopy measurements of local density of states and controlled annealing of the sample allowed for imaging of a clean structure and reproducible probing of band gap and electronic states.
Article
Chemistry, Multidisciplinary
Kaihui Li, Feiping Xiao, Wen Guan, Yulong Xiao, Chang Xu, Jinding Zhang, Chenfang Lin, Dong Li, Qingjun Tong, Si-Yu Li, Anlian Pan
Summary: Moire superlattices exhibit a magnification effect and are sensitive to both external disturbances and internal atomic reconstructions. Long-wavelength WS2 superlattices can be reconstructed into various moire morphologies, ranging from regular hexagons to heavily deformed shapes. The interaction between external nonuniform heterostrain and intrinsic atomic reconstruction is responsible for this interesting evolution of moire structures.
Article
Nanoscience & Nanotechnology
Daniel J. Trainer, Jouko Nieminen, Fabrizio Bobba, Baokai Wang, Xiaoxing Xi, Arun Bansil, Maria Iavarone
Summary: In this study, the authors investigated common point defects in monolayer MoS2 using low-temperature scanning tunneling microscopy and spectroscopy. They identified the defects as molybdenum vacancies based on their characteristic in-gap resonances. The study also revealed the role of the substrate in the band structure of defective MoS2 monolayers.
NPJ 2D MATERIALS AND APPLICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Shuting Peng, Christopher Lane, Yong Hu, Mingyao Guo, Xiang Chen, Zeliang Sun, Makoto Hashimoto, Donghui Lu, Zhi-Xun Shen, Tao Wu, Xianhui Chen, Robert S. Markiewicz, Yao Wang, Arun Bansil, Stephen D. Wilson, Junfeng He
Summary: By combining experimental and theoretical studies, we investigated the pseudogap state of the cuprate superconductor Sr2IrO4. Our findings show that the pseudogap state in Sr2IrO4 exhibits different characteristics compared to competing orders, with a zero scattering wave vector and limited correlation length.
NPJ QUANTUM MATERIALS
(2022)
Review
Physics, Condensed Matter
Johannes Nokelainen, Bernardo Barbiellini, Jan Kuriplach, Stephan Eijt, Rafael Ferragut, Xin Li, Veenavee Kothalawala, Kosuke Suzuki, Hiroshi Sakurai, Hasnain Hafiz, Katariina Pussi, Fatemeh Keshavarz, Arun Bansil
Summary: Studying the redox mechanisms in Li-ion batteries is crucial for the rational design of next-generation battery materials. This review explores spectroscopic descriptors to gain insights into the atomic-scale characteristics of redox orbitals and provides an understanding of the workings of lithium-ion batteries.
Article
Chemistry, Multidisciplinary
Bahadur Singh, Hsin Lin, Arun Bansil
Summary: Interest in topological materials is growing due to their conceptual novelty and potential for transformative new technologies. This perspective presents recent research on understanding the role of geometry and topology in generating topological states and their responses. Effective strategies for topological materials discovery and future research directions are also discussed.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Jian-Xiang Qiu, Christian Tzschaschel, Junyeong Ahn, Anyuan Gao, Houchen Li, Xin-Yue Zhang, Barun Ghosh, Chaowei Hu, Yu-Xuan Wang, Yu-Fei Liu, Damien Berube, Thao Dinh, Zhenhao Gong, Shang-Wei Lien, Sheng-Chin Ho, Bahadur Singh, Kenji Watanabe, Takashi Taniguchi, David C. Bell, Hai-Zhou Lu, Arun Bansil, Hsin Lin, Tay-Rong Chang, Brian B. Zhou, Qiong Ma, Ashvin Vishwanath, Ni Ni, Su-Yang Xu
Summary: Using circularly polarized light, researchers have observed helicity-dependent optical control of fully compensated antiferromagnetic order in a topological axion insulator called MnBi2Te4. This optical control and circular dichroism are based on the optical axion electrodynamics and can potentially be used to control PT-symmetric antiferromagnets and create dissipationless circuits using topological edge states.
Article
Multidisciplinary Sciences
Anyuan Gao, Yu-Fei Liu, Jian-Xiang Qiu, Barun Ghosh, Thais V. Trevisan, Yugo Onishi, Chaowei Hu, Tiema Qian, Hung-Ju Tien, Shao-Wen Chen, Mengqi Huang, Damien Berube, Houchen Li, Christian Tzschaschel, Thao Dinh, Zhe Sun, Sheng-Chin Ho, Shang-Wei Lien, Bahadur Singh, Kenji Watanabe, Takashi Taniguchi, David C. Bell, Hsin Lin, Tay-Rong Chang, Chunhui Rita Du, Arun Bansil, Liang Fu, Ni Ni, Peter P. Orth, Qiong Ma, Su-Yang Xu
Summary: This article reports a quantum metric nonlinear Hall effect induced by interfacing even-layered MnBi2Te4 with black phosphorus. The effect switches direction upon reversing the antiferromagnetic spins and exhibits distinct scaling.
Article
Materials Science, Multidisciplinary
Hung-Yu Yang, Jonathan Gaudet, Rahul Verma, Santu Baidya, Faranak Bahrami, Xiaohan Yao, Cheng-Yi Huang, Lisa DeBeer-Schmitt, Adam A. Aczel, Guangyong Xu, Hsin Lin, Arun Bansil, Bahadur Singh, Fazel Tafti
Summary: We investigate the magnetic and electronic transport properties of NdAlGe, a Weyl semimetal which breaks inversion and time-reversal symmetries. The material displays an incommensurate spin density wave and transitions to a commensurate ferrimagnetic state at low temperatures. Small-angle neutron scattering reveals the formation of ferrimagnetic domains with different characteristic length scales in real space. Interestingly, unlike NdAlSi, NdAlGe exhibits two different regimes of anomalous Hall effect, one governed by intrinsic Berry curvature and the other by extrinsic disorders/spin fluctuations.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Hao-Jen You, Bo-Ying Su, Yi-Ting Chiang, Tse-Hsiao Li, Hsu-Shen Chu, Hsin Lin
Summary: The thermoelectric properties of n-type doped Sr2Si and Sr2Ge were investigated using first-principles density functional theory calculations and semi-classical Boltzmann transport theory. The multi-band feature in the conduction band of Sr2Ge leads to a higher Seebeck coefficient, resulting in a higher power factor. The phonon transport calculations predict ultra-low lattice thermal conductivity for both materials, with a maximum figure of merit of 1.44 for Sr2Ge at 900 K.
MATERIALS TODAY PHYSICS
(2023)
Article
Physics, Multidisciplinary
Christopher Lane, Ruiqi Zhang, Bernardo Barbiellini, Robert S. Markiewicz, Arun Bansil, Jianwei Sun, Jian-Xin Zhu
Summary: The discovery of superconductivity in doped infinite-layer nickelates has attracted significant attention. The authors used a quantum many-body approach to investigate the electronic and magnetic properties of LaNiO2, providing insights into the suppressed long-range order and magnetic excitation spectrum in the nickelates. They found that the magnetic properties of the infinite-layer nickelates are closer to those of doped cuprates, rather than undoped cuprates. The study gives insights into the origin of strong magnetic competition in the infinite-layer nickelates and their relationship with the cuprates.
COMMUNICATIONS PHYSICS
(2023)
Article
Multidisciplinary Sciences
Sathya R. Chitturi, Zhurun Ji, Alexander N. Petsch, Cheng Peng, Zhantao Chen, Rajan Plumley, Mike Dunne, Sougata Mardanya, Sugata Chowdhury, Hongwei Chen, Arun Bansil, Adrian Feiguin, Alexander I. Kolesnikov, Dharmalingam Prabhakaran, Stephen M. Hayden, Daniel Ratner, Chunjing Jia, Youssef Nashed, Joshua J. Turner
Summary: This research utilizes a machine learning platform combined with linear spin wave theory simulations to extract and optimize advanced models for ordered magnetic systems using inelastic neutron scattering data. It provides a framework for real-time analysis of experimental data in condensed matter.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Jouko Nieminen, Sayandip Dhara, Wei -Chi Chiu, Eduardo R. Mucciolo, Arun Bansil
Summary: Using an atomistic tight-binding model, this study investigates the characteristics of a Josephson junction formed by monolayers of MoS2 sandwiched between Pb superconducting electrodes. By deriving and applying a Green's function-based formulation, the authors compute the Josephson current and the local density of states in the junction. Their analysis uncovers the presence of triplet superconducting correlations and spin-polarized subgap states in the MoS2 monolayers. The formulation presented in this study can be extended to accurately model Josephson junction physics in other systems that require atomistic details at large scales.
Article
Materials Science, Multidisciplinary
Jinwoong Kim, Cheng-Yi Huang, Hsin Lin, David Vanderbilt, Nicholas Kioussis
Summary: The researchers propose that pristine bulk Bi can serve as a three-dimensional analog of the SSH model, demonstrating the existence of topologically nontrivial and trivial domain walls and providing criteria for determining the Zak phase of domain walls based on parity eigenvalues. They suggest that the dimerization reversal in Bi and the formation of domain walls can be achieved through intense femtosecond laser excitations.
Article
Materials Science, Multidisciplinary
Debasis Dutta, Barun Ghosh, Bahadur Singh, Hsin Lin, Antonio Politano, Arun Bansil, Amit Agarwal
Summary: Plasmonics in topological semimetals provide opportunities for fundamental physics exploration and technological applications. We found two distinct plasmon modes in CoSi with different dispersions and long lifetimes.
Article
Materials Science, Multidisciplinary
Ruiqi Zhang, Cheng-Yi Huang, Jamin Kidd, Robert S. Markiewicz, Hsin Lin, Arun Bansil, Bahadur Singh, Jianwei Sun
Summary: This paper reports the discovery of a topological state with pseudonodal surface and double-Weyl fermions in cerium hexaboride (CeB6). By analyzing the electronic states, the researchers find protected band crossings in CeB6 and predict a giant anomalous Hall conductivity.
Article
Materials Science, Multidisciplinary
Wei Tao, Zheng Jue Tong, Anirban Das, Duc-Quan Ho, Yudai Sato, Masahiro Haze, Junxiang Jia, Yande Que, Fabio Bussolotti, K. E. Johnson Goh, BaoKai Wang, Hsin Lin, Arun Bansil, Shantanu Mukherjee, Yukio Hasegawa, Bent Weber
Summary: The study investigates the strongly proximity-coupled heterostructures of monolayer 1T'-WTe2 grown on NbSe2, revealing a hybrid electronic structure with multiband superconductivity induced by proximity to WTe2. A material-specific tight-binding model quantitatively captures the hybridized heterostructure and accurately predicts the induced order parameter in the WTe2 monolayer bulk. The detailed multiband analysis of the hybrid electronic structure provides a useful tool for spatial mapping of induced order parameters in atomically thin topological materials.