Article
Multidisciplinary Sciences
H. Lu, M. Rossi, A. Nag, M. Osada, D. F. Li, K. Lee, B. Y. Wang, M. Garcia-Fernandez, S. Agrestini, Z. X. Shen, E. M. Been, B. Moritz, T. P. Devereaux, J. Zaanen, H. Y. Hwang, Ke-Jin Zhou, W. S. Lee
Summary: The discovery of superconductivity in infinite-layer nickelates brings us closer to a material class similar to cuprate superconductors. Measurements of magnetic excitations in these nickelates showed that undoped NdNiO2 possesses a branch of dispersive excitations with a bandwidth of approximately 200 milli-electron volts.
Review
Physics, Multidisciplinary
Yusuke Nomura, Ryotaro Arita
Summary: The recent discovery of superconductivity in doped infinite layer nickelates RNiO2 is intriguing, as they are isostructural to doped (Ca, Sr)CuO2 which exhibit superconductivity at about 110 K. Investigating the similarities and differences between these oxides will provide new insights into the mechanism of high Tc superconductivity in correlated electron systems. This paper reviews experimental and theoretical works on the new superconductor and discusses future prospects for the 'nickel age' of superconductivity.
REPORTS ON PROGRESS IN PHYSICS
(2022)
Article
Physics, Multidisciplinary
Andreas Kreisel, Brian M. Andersen, Astrid T. Romer, Ilya M. Eremin, Frank Lechermann
Summary: The study investigated the superconducting properties of infinite-layer nickelates, revealing a superconducting instability transition driven by strong fluctuations in the dz2 orbital states. The properties of the superconducting condensates were discussed based on experiments probing the detailed superconducting gap structure.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Zhen Yang, Kui-juan Jin, Yulin Gan, Cheng Ma, Zhicheng Zhong, Ye Yuan, Chen Ge, Er-Jia Guo, Can Wang, Xiulai Xu, Meng He, Dongxiang Zhang, Guozhen Yang
Summary: A photon-induced quantum phase transition from the Kondo-Mott insulating state to the low temperature metallic state, accompanied by a change in magnetoresistance from negative to positive, has been observed in infinite-layer NdNiO2 films. The antiferromagnetic coupling and Kondo effect are effectively suppressed by manipulating the electronic correlation of Ni-3d and Nd-5d electrons under photoirradiation. The critical temperature Tc of the superconducting-like transition exhibits a dome-shaped evolution with a maximum value of about 42 K, and the Hall effect measurements confirm that electrons dominate the transport process. These findings suggest that photoinduction is a promising approach to control quantum phase transitions by manipulating electronic correlations in Mott-like insulators, and provide insights into the possibility of superconductivity in electron-doped nickelates.
Article
Materials Science, Multidisciplinary
Zhao Liu, Chenchao Xu, Chao Cao, W. Zhu, Z. F. Wang, Jinlong Yang
Summary: The electronic structure of the nickelate superconductor NdNiO2 is studied upon hole doping, revealing strong intrinsic hybridization between strongly correlated states and itinerant electrons, forming a valence-fluctuating correlated metal. Hund's rule plays a dominant role in the lightly doped compound, with intricate effects on Ni-3d orbitals. Hole doping leads to nonmonotonic changes in electron occupation and flipping orbital configurations in the overdoped regime. These findings provide insights into electron pairing and superconductivity.
Article
Physics, Multidisciplinary
Y. -t. Hsu, M. Osada, B. Y. Wang, M. Berben, C. Duffy, S. P. Harvey, K. Lee, D. Li, S. Wiedmann, H. Y. Hwang, N. E. Hussey
Summary: This study investigates the resistivity behavior in undoped nickelate materials and examines the impact of disorder and doping on its temperature dependence. The results reveal that the level of doping has little correlation with the magnitude and onset temperature of the resistivity upturn, while the different rare-earth families play a crucial role in the evolution of the insulating behavior.
FRONTIERS IN PHYSICS
(2022)
Editorial Material
Chemistry, Physical
Marc Gabay, Stefano Gariglio, Jean-Marc Triscone
Summary: Epitaxial growth followed by topotactic reduction can produce superconducting nickelate phases with the same hole-doping level as chemical substitution, while maintaining structural integrity.
Article
Multidisciplinary Sciences
Berit H. Goodge, Danfeng Li, Kyuho Lee, Motoki Osada, Bai Yang Wang, George A. Sawatzky, Harold Y. Hwang, Lena F. Kourkoutis
Summary: The recent discovery of superconductivity in Nd0.8Sr0.2NiO2 has led to questions about the underlying electronic structure hierarchy. By using locally resolved electron energy-loss spectroscopy, the Mott-Hubbard character of Nd1-xSrxNiO2 was directly probed, revealing evidence of a multiband electronic structure in the superconducting infinite-layer nickelates.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Chemistry, Multidisciplinary
Wenjie Sun, Yueying Li, Ruxin Liu, Jiangfeng Yang, Jiayi Li, Wei Wei, Gangjian Jin, Shengjun Yan, Haoying Sun, Wei Guo, Zhengbin Gu, Zengwei Zhu, Yue Sun, Zhixiang Shi, Yu Deng, Xuefeng Wang, Yuefeng Nie
Summary: Superconductivity has recently been found in infinite-layer nickelates, which provides new opportunities for exploring high-temperature superconductivity mechanisms. However, unlike cuprates, nickelates exhibit a multi-band electronic structure and unexpected isotropic superconductivity, challenging the cuprate-like picture in nickelates.
ADVANCED MATERIALS
(2023)
Article
Physics, Applied
Yaoyao Ji, Junhua Liu, Lin Li, Zhaoliang Liao
Summary: The discovery of an infinite layer nickelate superconductor in 2019 marked a new era of nickel-based superconductivity and provided opportunities to understand the origin of high-T-c superconductivity. Tremendous efforts are now being made in both experimental and theoretical aspects to explore this new superconducting family.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Physics, Multidisciplinary
P. Puphal, V. Pomjakushin, R. A. Ortiz, S. Hammoud, M. Isobe, B. Keimer, M. Hepting
Summary: In this study, the time dependence of the topotactic transformation from LaNiO3 to LaNiO2 was investigated using x-ray diffraction and gas extraction techniques. It was found that the hydrogen introduced during the transformation is confined to grain boundaries or secondary-phase precipitates and does not noticeably affect the crystal structure and physical properties of the primary LaNiO2 phase.
FRONTIERS IN PHYSICS
(2022)
Article
Physics, Multidisciplinary
Jennifer Fowlie, Marios Hadjimichael, Maria M. Martins, Danfeng Li, Motoki Osada, Bai Yang Wang, Kyuho Lee, Yonghun Lee, Zaher Salman, Thomas Prokscha, Jean-Marc Triscone, Harold Y. Hwang, Andreas Suter
Summary: Muon spin rotation/relaxation studies have revealed the coexistence of intrinsic magnetic ground state and superconductivity in superconducting infinite-layer nickelates, regardless of rare earth ion or doping. This magnetism, likely to be antiferromagnetic and short-range ordered, is qualitatively distinct from doped cuprates and resembles that of some iron pnictides and heavy fermion compounds.
Article
Physics, Multidisciplinary
Ruiqi Zhang, Christopher Lane, Bahadur Singh, Johannes Nokelainen, Bernardo Barbiellini, Robert S. Markiewicz, Arun Bansil, Jianwei Sun
Summary: By comparing the electronic structures of LaNiO2 and NdNiO2, the role of Nd 4f electrons in shaping the ground state of NdNiO2 is revealed, showing strong similarities between the two compounds except for the effects of the 4f electrons. The hybridization between Nd 4f and Ni 3d orbitals significantly modifies the Fermi surfaces of different magnetic states, and the competition between magnetically ordered phases mainly depends on the gaps in the Ni 3d(x2-y2) band. The study also found similarities in the on-site Hubbard U values between nickelates and cuprates, but the value of the Hund's coupling J(H) is sensitive to the Nd magnetic moment. Additionally, NdNiO2 exhibits 3D magnetism with competing antiferromagnetic and (interlayer) ferromagnetic exchange, contributing to the lower Tc compared to cuprates.
COMMUNICATIONS PHYSICS
(2021)
Article
Physics, Applied
Guillaume Krieger, Aravind Raji, Laurent Schlur, Gilles Versini, Corinne Bouillet, Marc Lenertz, Jerome Robert, Alexandre Gloter, Nathalie Viart, Daniele Preziosi
Summary: The recent discovery of a zero-resistance state in nickel-based compounds has reignited interest in the long-standing problem of high-critical temperature superconductivity in condensed matter, especially due to the similarities between infinite-layer nickelates and cuprates. However, the electronic properties of infinite-layer nickelates are remarkably original, which designates them as a new class of oxide superconductors. This study reports on the magnetic properties of Nd1-x Sr (x) NiO2 thin films with and without a SrTiO3 capping-layer, highlighting the important role of the capping-layer in controlling the magnetoresistance.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Chemistry, Physical
Davide Romanin, Lorenzo Monacelli, Raffaello Bianco, Ion Errea, Francesco Mauri, Matteo Calandra
Summary: The study examines the phase transition of carbon chains, showing the significant role of quantum anharmonicity and predicting an insulator-to-metal transition at high temperatures within polyyne phases in insulating nanotubes with a large dielectric constant.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Yi Cheng, Guang Cui, Changhao Liu, Zhetong Liu, Longge Yan, Bingyao Liu, Hao Yuan, Pengcheng Shi, Jun Jiang, Kewen Huang, Kun Wang, Shuting Cheng, Junliang Li, Peng Gao, Xinfang Zhang, Yue Qi, Zhongfan Liu
Summary: The dynamic joule heating system is designed for continuous synthesis of graphene fibers, achieving ultrashort high-temperature treatment with low electric energy consumption. The current flowing through the fibers can manipulate the configuration of graphene sheets and induce alignment in order to improve the electrical and mechanical performances of the graphene fibers.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Feng Yu, Kun Wang, Lingzhi Cui, Shengli Wang, Ming Hou, Feng Xiong, Ruqiang Zou, Peng Gao, Hailin Peng, Zhongfan Liu
Summary: This study proposes a method for surface reinforcement of titanium alloy bipolar plates using a vertical graphene coating, which effectively reduces the corrosion rate and interfacial contact resistance (ICR) in PEMFC operating environments, while improving thermal conductivity and water contact angle. The research provides a new opportunity for reinforcing metallic surfaces in high-performance electrodes used in energy and catalyst applications.
ADVANCED MATERIALS
(2022)
Article
Multidisciplinary Sciences
A. Nag, A. Nocera, S. Agrestini, M. Garcia-Fernandez, A. C. Walters, Sang-Wook Cheong, S. Johnston, Ke-Jin Zhou
Summary: This study unveils the hidden quadrupolar constituent in Y2BaNiO5 and demonstrates its unique collective dispersion using Ni L-3-edge resonant inelastic x-ray scattering.
NATURE COMMUNICATIONS
(2022)
Article
Physics, Multidisciplinary
M. Hepting, M. Bejas, A. Nag, H. Yamase, N. Coppola, D. Betto, C. Falter, M. Garcia-Fernandez, S. Agrestini, Ke-Jin Zhou, M. Minola, C. Sacco, L. Maritato, P. Orgiani, H. Wei, K. M. Shen, D. G. Schlom, A. Galdi, A. Greco, B. Keimer
Summary: Resonant inelastic x-ray scattering was used to study the propagation of plasmons in electron-doped cuprate Sr0.9La0.1CuO2. The study revealed the presence of a plasmon gap of around 120 meV in Sr0.9La0.1CuO2, indicating that the low-energy plasmons in this material are not strictly acoustic. Analysis of scattering data from other cuprates suggests that the plasmon gap is a common feature and its magnitude is related to the interlayer hopping. These findings demonstrate the three-dimensionality of charge dynamics in layered cuprates and offer a new method to determine the interlayer hopping parameter.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Fang Liu, Jiashen Meng, Hong Wang, Shulin Chen, Ruohan Yu, Peng Gao, Jinsong Wu
Summary: This study reveals the phase transformations and electrochemical mechanism of tellurium (Te) in potassium-ion batteries (PIBs) using in situ high-resolution transmission electron microscopy and electron diffraction. The results show that the potassium storage in Te is highly reversible, providing implications for the future design of high-performance nanostructured cathodes for PIBs.
Article
Multidisciplinary Sciences
Lichen Wang, Guanhong He, Zichen Yang, Mirian Garcia-Fernandez, Abhishek Nag, Kejin Zhou, Matteo Minola, Matthieu Le Tacon, Bernhard Keimer, Yingying Peng, Yuan Li
Summary: By studying two members of the model Hg family, it is found that the energy of magnetic fluctuations may limit the highest critical temperature of cuprate superconductors, providing important clues for understanding the superconducting mechanism. Furthermore, the correlation between paramagnon energy and maximal critical temperature is also confirmed in other cuprate families.
NATURE COMMUNICATIONS
(2022)
Article
Physics, Multidisciplinary
M. Zhu, D. J. Voneshen, S. Raymond, O. J. Lipscombe, C. C. Tam, S. M. Hayden
Summary: In this study, we demonstrate through inelastic neutron scattering that there are low-energy collective spin fluctuations near the superconducting critical temperature and near the doping p* in cuprate superconductors. These spin fluctuations are attributed to the collapse of the pseudogap combined with an underlying tendency to magnetic order. They exist across the superconducting phase diagram and may be related to the strange metal behavior observed in overdoped cuprates.
Article
Multidisciplinary Sciences
Xiang Ding, Charles C. Tam, Xuelei Sui, Yan Zhao, Minghui Xu, Jaewon Choi, Huaqian Leng, Ji Zhang, Mei Wu, Haiyan Xiao, Xiaotao Zu, Mirian Garcia-Fernandez, Stefano Agrestini, Xiaoqiang Wu, Qingyuan Wang, Peng Gao, Sean Li, Bing Huang, Ke-Jin Zhou, Liang Qiao
Summary: The newly discovered nickelate superconductors only exist in epitaxial thin films synthesized by a topotactic reaction with metal hydrides. This chemical reaction changes the structure of nickelates and introduces hydrogen, which affects the physical properties of the materials. By using secondary-ion mass spectroscopy, abundant hydrogen was detected in Sr-doped Nd0.8Sr0.2NiO2H epitaxial films, and its presence was found to be critical for superconductivity within a narrow doping range of 0.22≤x≤0.28.
Article
Multidisciplinary Sciences
Hiroki Ueda, Mirian Garcia-Fernandez, Stefano Agrestini, Carl P. Romao, Jeroen van den Brink, Nicola A. Spaldin, Ke-Jin Zhou, Urs Staub
Summary: The concept of chirality plays a crucial role in various natural phenomena. Recent studies in condensed matter physics have revealed the existence of chiral fermions and their connection to emergent phenomena and topology. However, experimental verification of chiral phonons in macroscopic systems remains challenging. In this study, we provide experimental evidence of chiral phonons using resonant inelastic X-ray scattering with circularly polarized X-rays. By studying the chiral material quartz, we demonstrate that circularly polarized X-rays couple to chiral phonons at specific positions in reciprocal space, allowing for the determination of the chiral dispersion of lattice modes. This experimental proof of chiral phonons introduces a new degree of freedom in condensed matter physics, with both fundamental importance and potential for exploring novel emergent phenomena based on chiral bosons.
Article
Multidisciplinary Sciences
Hebatalla Elnaggar, Abhishek Nag, Maurits W. Haverkort, Mirian Garcia-Fernandez, Andrew Walters, Ru-Pan Wang, Ke-Jin Zhou, Frank de Groot
Summary: In this study, the observation of triple-magnon excitation in alpha-Fe2O3 challenges the conventional wisdom that only 1- and 2-magnon excitations are possible in a resonant inelastic X-ray scattering experiment. The researchers demonstrate how a two-photon scattering process can generate exotic higher-rank magnons and discuss the relevance of these quasiparticles for magnon-based applications.
NATURE COMMUNICATIONS
(2023)
Correction
Multidisciplinary Sciences
Lichen Wang, Guanhong He, Zichen Yang, Mirian Garcia-Fernandez, Abhishek Nag, Kejin Zhou, Matteo Minola, Matthieu Le Tacon, Bernhard Keimer, Yingying Peng, Yuan Li
NATURE COMMUNICATIONS
(2023)
Article
Energy & Fuels
Robert A. House, Gregory J. Rees, Kit McColl, John-Joseph Marie, Mirian Garcia-Fernandez, Abhishek Nag, Ke-Jin Zhou, Simon Cassidy, Benjamin J. Morgan, M. Saiful Islam, Peter G. Bruce
Summary: Oxide ions in transition metal oxide cathodes can store charge at high voltage. However, during charging, the oxidized oxide ions form trapped O-2, resulting in undesirable voltage hysteresis. By studying ribbon-ordered Na-0.6[Li0.2Mn0.8]O-2, the authors discovered the delocalized electron holes on oxide ions before O-2 formation. The understanding of these hole states is crucial for realizing reversible high-voltage O-redox cathodes.
Article
Chemistry, Multidisciplinary
Yunke Zhu, Yunzhou Deng, Peng Bai, Xinan Wu, Yige Yao, Qinyun Liu, Jingjing Qiu, An Hu, Zhenyu Tang, Wenjin Yu, Yaolong Li, Pengzuo Jiang, Zhetong Liu, Peng Gao, Yanlei Hao, Wangxiao Jin, Desui Chen, Xitong Zhu, Yizheng Jin, Yunan Gao
Summary: This study demonstrates efficient, bright, and long lifetime red Nc-LEDs based on anisotropic nanocrystals. By modifying the substrate's surface properties and controlling the interactions among nanocrystals, a self-assembled layer with a high distribution of in-plane transitions dipole moment of 95% is successfully achieved, resulting in an out-coupling factor of 37%.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Jaewon Choi, Jiemin Li, Abhishek Nag, Jonathan Pelliciari, Hannah Robarts, Charles C. Tam, Andrew Walters, Stefano Agrestini, Mirian Garcia-Fernandez, Dongjoon Song, Hiroshi Eisaki, Steve Johnston, Riccardo Comin, Hong Ding, Ke-Jin Zhou
Summary: This study reveals the spatial symmetry of charge density waves (CDWs) in copper-oxide superconductors using high-resolution resonant inelastic x-ray scattering. The experimental results show anisotropic CDW peaks with elliptical shapes in Bi2Sr2-xLaxCuO6+δ, interpreted as evidence of unidirectional charge stripes. This work provides new insights into the symmetry and microscopic description of CDWs in copper-oxide superconductors.
ADVANCED MATERIALS
(2023)
Article
Multidisciplinary Sciences
Riccardo Arpaia, Leonardo Martinelli, Marco Moretti Sala, Sergio Caprara, Abhishek Nag, Nicholas B. Brookes, Pietro Camisa, Qizhi Li, Qiang Gao, Xingjiang Zhou, Mirian Garcia-Fernandez, Ke-Jin Zhou, Enrico Schierle, Thilo Bauch, Ying Ying Peng, Carlo Di Castro, Marco Grilli, Floriana Lombardi, Lucio Braicovich, Giacomo Ghiringhelli
Summary: Charge density fluctuations are found to be associated with the quantum critical point of the strange metal phase, strengthening the role of charge order and providing insights into high-temperature superconductivity.
NATURE COMMUNICATIONS
(2023)