Article
Chemistry, Multidisciplinary
E. Rongione, L. Baringthon, D. She, G. Patriarche, R. Lebrun, A. Lemaitre, M. Morassi, N. Reyren, M. Micica, J. Mangeney, J. Tignon, F. Bertran, S. Dhillon, P. Le Fevre, H. Jaffres, J. -m. George
Summary: By combining spin- and angle-resolved photoemission spectroscopy with time-resolved THz emission spectroscopy, it is demonstrated that spin-charge conversion mainly arises from the surface state in ultrathin films of Bi1-xSbx. The robustness of the surface state and the significant conversion efficiency in epitaxial Bi1-xSbx thin films bring new perspectives for ultra-low power magnetic random-access memories and broadband THz generation.
Article
Chemistry, Multidisciplinary
Antonio Rossi, Cameron Johnson, Jesse Balgley, John C. Thomas, Luca Francaviglia, Riccardo Dettori, Andreas K. Schmid, Kenji Watanabe, Takashi Taniguchi, Matthew Cothrine, David G. Mandrus, Chris Jozwiak, Aaron Bostwick, Erik A. Henriksen, Alexander Weber-Bargioni, Eli Rotenberg
Summary: We investigated the electronic properties of a graphene and a-ruthenium trichloride (a-RuCl3) heterostructure and observed massive charge transfer from graphene to a-RuCl3. This strong coupling between the two materials can lead to novel electronic phenomena. Understanding these properties is crucial for designing next generation low-power optoelectronic devices.
Article
Physics, Applied
Hayder A. Al-Atabi, Xiaotian Zhang, Shanmei He, Cheng Chen, Yulin Chen, Eli Rotenberg, James H. Edgar
Summary: This study aims to investigate the stoichiometry and electronic structure of scandium nitride (ScN) by growing ScN (100) single crystals under specific conditions and obtaining core level spectra data using X-ray photoelectron spectroscopy.
APPLIED PHYSICS LETTERS
(2022)
Review
Chemistry, Multidisciplinary
Yiwei Li, Qiang Wan, Nan Xu
Summary: The past decade has seen significant progress in 2D materials, particularly in the field of artificial moire superlattices. These superlattices exhibit a range of quantum phenomena beyond their constituent materials, thanks to their nontrivial electronic structures. Modern ARPES techniques allow for direct visualization of these electronic structures, providing valuable insights into the fundamental physics of moire superlattice systems and guiding the design of novel devices.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Yu-Chen Leng, Tao Chen, Miao-Ling Lin, Xiao-Li Li, Xue-Lu Liu, Ping-Heng Tan
Summary: This study investigated the zenith-angle resolved polarized Raman spectra of graphene and graphite deposited on different substrates. The intensity of the G mode showed zenith-angle dependence and was sensitive to the underlying substrates. A proposed model successfully explained the zenith-angle resolved polarized Raman intensity of the G mode.
Article
Chemistry, Multidisciplinary
Gary Wan, Alex Croot, Neil A. Fox, Mattia Cattelan
Summary: This paper presents an alternative method based on thermalized photoelectrons for investigating the unoccupied electronic states emitted from crystal surfaces. The approach is demonstrated on diamond and copper, revealing the unoccupied state band structure and allowing for experimental determination of the transverse effective mass. This method offers a convenient path for interpreting angle-resolved photoemission data and extracting information about empty states.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Physics, Condensed Matter
Issei Suzuki, Sakiko Kawanishi, Kiyohisa Tanaka, Takahisa Omata, Shin-ichiro Tanaka
Summary: In this study, angle-resolved photoemission spectroscopy (ARPES) was used to investigate the electronic band structures of single-crystalline tin(II) sulfide (SnS) over a wide energy range (-10 eV to Fermi level). The contributions of different atomic orbitals to the SnS valence band were determined based on their symmetries with respect to the mirror plane. The experimental results were in agreement with first-principles calculations, and revealed that the S 3p(y) and 3p(z) orbitals strongly contributed near the Z and Gamma points, respectively, while the contribution of the S 3p(x) orbital was minimal and located 2 eV below the valence band maximum.
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2023)
Article
Physics, Multidisciplinary
Zhengwang Cheng, Zhilong Hu, Shaojian Li, Xinguo Ma, Zhifeng Liu, Mei Wang, Jing He, Wei Zou, Fangsen Li, Zhiqiang Mao, Minghu Pan
Summary: The study investigates the band structure of the "square-net" topological material ZrGeS, revealing its unique electronic properties suitable for exploring Dirac-fermions related physics and applications of topological devising.
NEW JOURNAL OF PHYSICS
(2021)
Article
Optics
Ming -Ming Yang, Heng Wu, Li Tan, Yue Ma, Ya-nan Zhao, Yi Liu, Fu-Rong Yang, Chun-Lin Wu, Xue-lu Liu, Bao-Lai Liang, Xiao-Li Li
Summary: Helicity-resolved Raman spectroscopy (HRRS) can effectively differentiate the Raman modes of two-dimensional (2D) layered materials based on phonon symmetry. This study systematically investigates the phonon helicity selection of MoS2 bulk in the basal and edge planes using HRRS. It is found that the crystal structure symmetry changes the helicity selection of the E1g, E12g, and A1g modes in the edge plane. Theoretical calculation results confirm that the E12g and A1g modes in the basal plane exhibit perfect helicity exchange, while the helicity selections of the E12g and A1g modes in the edge plane are eliminated or weakened. This study provides references for the phonon helicity selection of 2D layered materials represented by MoS2.
Article
Chemistry, Multidisciplinary
Jacob Pettine, Paolo Maioli, Fabrice Vallee, Natalia Del Fatti, David J. Nesbitt
Summary: We investigated the effects of nanoscale structure on the femtosecond dynamics of gold nanoparticles using time-, angle-, and energy-resolved photoemission spectroscopy. We found that nanoparticles as small as 10 nm serve as excellent platforms for studying intrinsic metal dynamics.
Article
Physics, Multidisciplinary
Shuaishuai Li, Taimin Miao, Chaohui Yin, Yinghao Li, Hongtao Yan, Yiwen Chen, Bo Liang, Hao Chen, Wenpei Zhu, Shenjin Zhang, Zhimin Wang, Fengfeng Zhang, Feng Yang, Qinjun Peng, Chengtian Lin, Hanqing Mao, Guodong Liu, Zuyan Xu, Lin Zhao, X. J. Zhou
Summary: In this study, spatially-resolved laser-based high-resolution angle resolved photoemission spectroscopy (ARPES) measurements were performed on the optimally-doped YBa2Cu3O7-delta (Y123) superconductor. For the first time, clear bulk electronic properties were observed in the region from the cleaved surface. The Fermi surface and band structures of Y123 were determined, and a nodeless superconducting gap consistent with the d+is gap form was identified.
Article
Materials Science, Multidisciplinary
M. Cattelan, C. J. Sayers, D. Wolverson, E. Carpene
Summary: Palladium diselenide (PdSe2) is an emerging 2D transition-metal dichalcogenide with tunable band gap. Experimental results show that the bulk state exhibits semiconducting properties and displays strong sensitivity to atomic arrangement and symmetry. These findings provide insight into the electronic configuration of PdSe2 and highlight additional capabilities of photoemission spectroscopy.
Article
Physics, Multidisciplinary
Xu-Chuan Wu, Shen Xu, Jian-Feng Zhang, Huan Ma, Kai Liu, Tian-Long Xia, Shan-Cai Wang
Summary: This paper investigates the magnetoresistance origin of single crystal CaAl4 with C2/m structure at low temperature, revealing unsaturated magnetoresistance of around 3000% at 2.5 K and 14 T as the fingerprints of XMR materials. The study uses a combination of ARPES and first-principles calculations to elaborate on the multiband features and anisotropic Fermi surfaces, explaining the discrepancies in the isotropic two-band model. Despite a structural phase transition from I4/mmm to C2/m, the subtle impact on the electronic structure is revealed through ARPES measurements, highlighting CaAl4 as a new reference material for exploring the XMR phenomena.
Article
Chemistry, Multidisciplinary
Fabio Bussolotti, Jing Yang, Hiroyo Kawai, Calvin Pei Yu Wong, Kuan Eng Johnson Goh
Summary: This study investigates the electronic properties of MoS2 monolayer interfaced with graphite using photoemission spectroscopy, revealing the significant impact of S-vacancies on core level and valence band binding energies. The results suggest that Fermi level pinning at deep S-vacancy gap states is responsible for the large electron injection barrier at the MoS2 ML interface with low work function metals.
Article
Chemistry, Multidisciplinary
Haruko Toyama, Ryota Akiyama, Satoru Ichinokura, Mizuki Hashizume, Takushi Iimori, Yukihiro Endo, Rei Hobara, Tomohiro Matsui, Kentaro Horii, Shunsuke Sato, Toru Hirahara, Fumio Komori, Shuji Hasegawa
Summary: This study reveals the crucial role of the interface between monolayer graphene and the SiC substrate in the superconductivity induced by Ca-intercalation. Through Ca-termination of SiC, the carbon layer at the interface changes to graphene, and Ca is intercalated between the graphene layers, leading to superconductivity. The relationship between the critical temperature and the normal-state conductivity exhibits an unusual dome-shaped pattern.
Article
Materials Science, Multidisciplinary
M. Berben, S. Smit, C. Duffy, Y-T Hsu, L. Bawden, F. Heringa, F. Gerritsen, S. Cassanelli, X. Feng, S. Bron, E. van Heumen, Y. Huang, F. Bertran, T. K. Kim, C. Cacho, A. Carrington, M. S. Golden, N. E. Hussey
Summary: Once doped away from their parent Mott insulating state, the hole-doped cuprates enter into many varied and exotic phases. The onset temperature of each phase is then plotted versus p-the number of doped holes per copper atom-to form a representative phase diagram. Apart from differences in the absolute temperature scales among the various families, the resultant phase diagrams are strikingly similar. In particular, the p values corresponding to optimal doping and to the end of the pseudogap phase are essentially the same for all cuprate families except for the single-layer Bi-based cuprate Bi2+z-yPbySr2-x-zLaxCuO6+delta (Bi2201). This anomaly arises partly due to the complex stoichiometry of this material and also to the different p values inferred from disparate measurements performed on samples with comparable superconducting transition temperatures T-c. Here, by combining measurements of in-plane resistivity in zero and high magnetic fields with angle-resolved photoemission spectroscopy studies, we argue that the phase diagram of Bi2201 may actually be similar to that realized in other families, supporting the notion of universality of p(opt) and p* in all hole-doped cuprates.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Laetitia Baringthon, Thi Huong Dang, Henri Jaffres, Nicolas Reyren, Jean-Marie George, Martina Morassi, Gilles Patriarche, Aristide Lemaitre, Francois Bertran, Patrick Le Fevre
Summary: Topological insulator spin-polarized surface states are attractive for spintronic applications due to their high conversion efficiencies. However, the contribution of topologically trivial bulk states is often disregarded, which may play a crucial role in experimental results and extracted conversion efficiencies. The research found that by reducing the film thickness, the presence of bulk states at the Fermi level could be avoided.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Chemistry, Physical
Dhani Nafday, Christine Richter, Olivier Heckmann, Weimin Wang, Jean-Michel Mariot, Uros Djukic, Ivana Vobornik, Patrick Lefevre, Amina Taleb-Ibrahimi, Julien Rault, Laurent Nicolai, Chin Shen Ong, Patrik Thunstrom, Karol Hricovini, Jan Minar, Igor Di Marco
Summary: In this study, angle-resolved photoemission spectroscopy and density functional theory are used to investigate the electronic structure of self-assembled Bi nanolines on the InAs(100) surface. The results suggest the presence of a flat band associated with the Bi nanolines, indicating a strongly polarized conductivity that makes them suitable for nanowire applications in nanotechnology. The coexistence with an accumulation layer indicates further functionalization potential.
APPLIED SURFACE SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Tommaso Antonelli, Warda Rahim, Matthew D. Watson, Akhil Rajan, Oliver J. Clark, Alisa Danilenko, Kaycee Underwood, Igor Markovic, Edgar Abarca-Morales, Sean R. Kavanagh, P. Le Fevre, F. Bertran, K. Rossnagel, David O. Scanlon, Phil D. C. King
Summary: Reducing the thickness of a material to two-dimensional can significantly impact the collective electronic states, such as magnetism and superconductivity. This study focuses on TiTe2 and investigates the electronic band structure evolution during the charge density wave (CDW) transition. The results reveal an orbital-selective band hybridisation at the CDW phase transition, which leads to a significant electronic energy gain. This research sheds new light on the control of electronic dimensionality in triggering the emergence of new collective states in 2D materials.
NPJ QUANTUM MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Raphael Salazar, Sara Varotto, Celine Vergnaud, Vincent Garcia, Stephane Fusil, Julien Chaste, Thomas Maroutian, Alain Marty, Frederic Bonell, Debora Pierucci, Abdelkarim Ouerghi, Francois Bertran, Patrick Le Fevre, Matthieu Jamet, Manuel Bibes, Julien Rault
Summary: Multilayers based on quantum materials have the potential to revolutionize microelectronics and optoelectronics. However, heterostructures incorporating quantum materials from different families remain scarce. In this study, we demonstrate the large-scale integration of compounds from two highly multifunctional families, perovskite oxides and transition-metal dichalcogenides, opening up new possibilities for manipulating the properties of transition-metal dichalcogenides through proximity effects.
Article
Physics, Condensed Matter
Paul Foulquier, Marcello Civelli, Marcelo Rozenberg, Alberto Camjayi, Joel Bobadilla, Dorothee Colson, Anne Forget, Pierre Thuery, Francois Bertran, Patrick Le Fevre, Veronique Brouet
Summary: Sr2IrO4 and Sr3Ir2O7 are two families of spin-orbit Mott insulators with distinct charge gaps and antiferromagnetic ground states. The impact of long-range magnetic order in Mott insulators appears to be different in these two families, as the resistivity shows almost no change at the magnetic transition in Sr2IrO4 and a significant change in Sr3Ir2O7.
EUROPEAN PHYSICAL JOURNAL B
(2023)
Article
Physics, Multidisciplinary
Tyler A. Cochran, Ilya Belopolski, Kaustuv Manna, Mohammad Yahyavi, Liu Yiyuan, Daniel S. Sanchez, Cheng Zi-Jia, Xian P. Yang, Daniel Multer, Yin Jia-Xin, Horst Borrmann, Alla Chikina, Jonas A. Krieger, Jaime Sanchez-Barriga, Patrick Le Fevre, Francois Bertran, Vladimir N. Strocov, Jonathan D. Denlinger, Chang Tay-Rong, Jia Shuang, Claudia Felser, Hsin Lin, Chang Guoqing, M. Zahid Hasan
Summary: In this Letter, the authors discovered the higher-fold topology of a chiral crystal using a combination of fine-tuned chemical engineering and photoemission spectroscopy. They identified all bulk branches of a higher-fold chiral fermion and revealed a multigap bulk boundary correspondence. This demonstration of multigap electronic topology will drive future research on unconventional topological responses.
PHYSICAL REVIEW LETTERS
(2023)
Article
Multidisciplinary Sciences
Hideaki Iwasawa, Kazuki Sumida, Shigeyuki Ishida, Patrick Le Fevre, Francois Bertran, Yoshiyuki Yoshida, Hiroshi Eisaki, Andres F. Santander-Syro, Taichi Okuda
Summary: The role of spin-orbit interaction in high-T-c cuprates has been reexamined due to recent experimental observations of spin-polarized electronic states. However, the origin of spin polarization in these cuprates remains unclear due to the complexity of the reported spin texture. In this study, spin- and angle-resolved photoemission spectroscopy (ARPES) data on symmetric momentum points have been presented to explore the intrinsic spin nature of the initial state. The findings reveal a very weak spin polarization along the nodal direction and no indication of spin-splitting in the band, suggesting a need for a revision of the simple application of spin-orbit interaction in high-T-c cuprates.
SCIENTIFIC REPORTS
(2023)
Article
Materials Science, Multidisciplinary
V. Palin, A. Anadon, S. Andrieu, Y. Fagot-Revurat, C. de Melo, J. Ghanbaja, O. Kurnosikov, S. Petit-Watelot, F. Bertran, J. -c. Rojas-Sanchez
Summary: This study explores a promising family of topological materials called half-Heuslers, which have high tunability and large spin Seebeck coefficient. The research findings provide a new pathway for the development of efficient spin interconversion materials.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Geoffroy Kremer, Aymen Mahmoudi, Meryem Bouaziz, Cleophanie Brochard-Richard, Lama Khalil, Debora Pierucci, Francois Bertran, Patrick Le Fevre, Mathieu G. Silly, Julien Chaste, Fabrice Oehler, Marco Pala, Federico Bisti, Abdelkarim Ouerghi
Summary: Metal monochalcogenides, such as InTe, exhibit diverse electronic properties based on their chemical composition, layer numbers, and stacking order. This study combined angle-resolved photoemission spectroscopy and density functional theory calculations to reveal the stability and properties of InTe. It was found that InTe has a tetragonal crystal structure, semiconducting behavior, and intrinsic p-type doping. The electronic band structure of InTe was highly anisotropic, with a large effective mass and in-plane anisotropy, making it interesting for electronic and thermoelectric applications.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Himanshu Lohani, Paul Foulquier, Patrick Le Fevre, Francois Bertran, Dorothee Colson, Anne Forget, Veronique Brouet
Summary: This study presents a direct observation of the evolution of the electronic structure of Co3Sn2S2 under different types of substitutions using angle-resolved photoemission spectroscopy. The results show clear shifts of selected bands, which are attributed to both doping and reduced magnetic splitting. Importantly, the effect of Fe and Ni substitutions cannot be accurately captured by density-functional theory calculations, indicating the importance of local behavior at the impurity site.
Article
Multidisciplinary Sciences
Cong Li, Jianfeng Zhang, Yang Wang, Hongxiong Liu, Qinda Guo, Emile Rienks, Wanyu Chen, Francois Bertran, Huancheng Yang, Dibya Phuyal, Hanna Fedderwitz, Balasubramanian Thiagarajan, Maciej Dendzik, Magnus H. Berntsen, Youguo Shi, Tao Xiang, Oscar Tjernberg
Summary: Using angle-resolved photoemission spectroscopy, the electronic structure of a noncentrosymmetric magnetic Weyl semimetal candidate NdAlSi was visualized, showing the emergence of new Weyl fermions in the ferrimagnetic state.
NATURE COMMUNICATIONS
(2023)
Article
Physics, Multidisciplinary
Meryem Bouaziz, Aymen Mahmoudi, Geoffroy Kremer, Julien Chaste, Cesar Gonzalez, Yannick J. Dappe, Francois Bertran, Patrick Le Fevre, Marco Pala, Fabrice Oehler, Jean-Christophe Girard, Abdelkarim Ouerghi
Summary: Recently, intriguing physical properties have been discovered in anisotropic semiconductors, where the non-uniformity of the in-plane electronic band structure often stems from low crystal symmetry. Atomic chains, which represent the ultimate downsizing limit for electronic materials, have emerged as a frontier in the field of one-dimensional quantum materials. Investigating the electronic and structural properties of chain-like InTe is crucial for understanding its applications in devices such as thermoelectrics. In this study, we employed scanning tunneling microscopy/scanning tunneling spectroscopy (STS) and density functional theory (DFT) calculations to directly observe the in-plane structural anisotropy in tetragonal InTe. Our results demonstrate the presence of one-dimensional In1+ chains in InTe and reveal a bandgap of approximately 0.40 +/- 0.02 eV located at the M point of the Brillouin zone. Additionally, we observed line defects in our sample, which were attributed to vacancies in the In1+ chains along the c-axis, a common feature in other TlSe-like compounds. Our STS and DFT findings confirm that the presence of In1+ induces a localized gap state near the valence band maximum, explaining the high intrinsic p-type doping of InTe that we also confirmed using angle-resolved photoemission spectroscopy.
PHYSICAL REVIEW RESEARCH
(2023)
Article
Materials Science, Multidisciplinary
Lama Khalil, Pietro Maria Forcella, Geoffroy Kremer, Federico Bisti, Julien Chaste, Jean-Christophe Girard, Fabrice Oehler, Marco Pala, Jean-Francois Dayen, Demetrio Logoteta, Mark Goerbig, Francois Bertran, Patrick Le Fevre, Emmanuel Lhuillier, Julien Rault, Debora Pierucci, Gianni Profeta, Abdelkarim Ouerghi
Summary: The electronic properties of alpha phase As2Te3 were investigated, revealing anisotropic 2D electronic states that are decoupled from the electronic structure of alpha-As2Te3 and attributed to single layer tellurene. This finding proposes the alpha-As2Te3 (100) surface as a promising platform for experimental exploration of the electronic band structure of single layer tellurene, which is otherwise difficult to access experimentally.
Article
Physics, Multidisciplinary
M. Blanco-Rey, R. Castrillo-Bodero, K. Ali, P. Gargiani, F. Bertran, P. M. Sheverdyaeva, J. E. Ortega, L. Fernandez, F. Schiller
Summary: The magnetic anisotropy and the electronic band structure are found to be interconnected in intermetallic compounds. The out-of-plane easy magnetization axis in EuAu2 is due to strong f-d band hybridization and Eu2+ valence, while the in-plane magnetization of GdAu2 is ruled by spin-orbit-split d bands, notably Weyl nodal lines occupied in the Gd3+ state. Regardless of the L value, a similar itinerant electron contribution to the anisotropy of analogous compounds is predicted.
PHYSICAL REVIEW RESEARCH
(2022)
