Article
Multidisciplinary Sciences
Thomas Hartke, Botond Oreg, Carter Turnbaugh, Ningyuan Jia, Martin Zwierlein
Summary: The Hubbard model of attractively interacting fermions is used to study fermion pairing. In this model, a crossover between tightly bound pairs and long-range Cooper pairs occurs, with a pseudo-gap region above the superfluid critical temperature. By directly observing a Hubbard lattice gas of fermionic potassium-40 atoms under a bilayer microscope, the nonlocal nature of fermion pairing is revealed. The study also provides insights into the pseudo-gap behavior in strongly correlated fermion systems.
Article
Materials Science, Multidisciplinary
Carsten Timm, Ankita Bhattacharya
Summary: Multiband effects in solids can result in fundamentally different electronic behavior, such as the emergence of Fermi surfaces in superconductors that break time-reversal symmetry. This study extends the analysis to include nonlocal pairing and consider internal degrees of freedom, focusing on even-parity pairing and providing symmetry analysis for several examples. The inclusion of nonlocal pairing expands the range of possible pairing symmetries, with a simple criterion for nodes in terms of form factor scalar products.
Article
Physics, Multidisciplinary
Ke Zhang, Shixuan Zhao, Zhanyang Hao, Shiv Kumar, Eike F. Schwier, Yingjie Zhang, Hongyi Sun, Yuan Wang, Yujie Hao, Xiaoming Ma, Cai Liu, Le Wang, Xiaoxiao Wang, Koji Miyamoto, Taichi Okuda, Chang Liu, Jiawei Mei, Kenya Shimada, Chaoyu Chen, Qihang Liu
Summary: Research has discovered distinct spin-momentum-layer locking phenomena in centrosymmetric crystals, with spin highly polarized along the Brillouin zone boundary and almost vanishing near the zone center. This sheds new light on the design metrics for future spintronic materials.
PHYSICAL REVIEW LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Shingo Kobayashi, Ankita Bhattacharya, Carsten Timm, P. M. R. Brydon
Summary: This study examines the emergence of superconductivity in the strong-coupling limit of the Hubbard model on the pyrochlore lattice. It focuses on the half-filling limit where the normal-state band structure exhibits a j = 3/2 semimetal. By introducing doping, it is shown that pairing is favored in a J = 2 quintet Eg state. The attractive interaction in this channel is due to the fact that Eg pairing on the pyrochlore lattice avoids the detrimental onsite repulsion. The calculations support the presence of a time-reversal symmetry-breaking superconducting phase with Bogoliubov Fermi surfaces.
Article
Multidisciplinary Sciences
Hisao Kobayashi, Yui Sakaguchi, Hayato Kitagawa, Momoko Oura, Shugo Ikeda, Kentaro Kuga, Shintaro Suzuki, Satoru Nakatsuji, Ryo Masuda, Yasuhiro Kobayashi, Makoto Seto, Yoshitaka Yoda, Kenji Tamasaku, Yashar Komijani, Premala Chandra, Piers Coleman
Summary: Using synchrotron radiation-based Mossbauer spectroscopy, we investigated the charge fluctuations of beta-YbAlB4's strange metal phase and observed the splitting of the absorption peak in the Fermi-liquid regime upon entering the critical regime. This splitting is interpreted as a result of single nuclear transition modulated by nearby electronic valence fluctuations, which are further enhanced by the formation of charged polarons. These critical charge fluctuations may serve as a distinctive signature of strange metals.
Article
Chemistry, Multidisciplinary
Zhipeng Wang, Jinho Byun, Zhen Wang, Yaolong Xing, Jinsol Seo, Jaekwang Lee, Sang Ho Oh
Summary: Polar surfaces are unstable and reactive due to uncompensated surface charges. Surface reconstructions, including atomic step and step-assisted reconstructions, play crucial roles in the charge compensation of polar oxide surfaces.
ADVANCED MATERIALS
(2023)
Article
Physics, Multidisciplinary
Michele Pini, Pierbiagio Pieri, Giancarlo Calvanese Strinati
Summary: In this study, the pair susceptibility of an attractive spin-polarized Fermi gas in the normal phase was calculated as a function of pair momentum. It was found that close to unitarity, there is a strong enhancement of FFLO pairing fluctuations, which could be observed experimentally as a pronounced peak in the pair-momentum distribution. The calculations were based on a self-consistent t-matrix approach and have been validated against experimental data for several thermodynamic quantities in the unitary balanced Fermi gas system.
PHYSICAL REVIEW RESEARCH
(2021)
Article
Materials Science, Multidisciplinary
O. Gingras, N. Allaglo, R. Nourafkan, M. Cote, A. -M. S. Tremblay
Summary: This study generalizes the frequency-dependent theory of superconductivity mediated by spin and charge fluctuations to include spin-orbit coupling in multiorbital systems. The authors characterize the superconducting states using quantum numbers, group theory, and phase distributions. They find that spin-orbit coupling leads to entanglement of spin and orbital quantum numbers and mixing between even- and odd-frequency correlations. The proposed phase diagram can resolve experimental contradictions.
Article
Chemistry, Multidisciplinary
Samya Banerjee, Juliusz A. Wolny, Mohsen Danaie, Nicolas P. E. Barry, Yisong Han, Houari Amari, Richard Beanland, Volker Schuenemann, Peter J. Sadler
Summary: In this study, two square-planar bis-thiolato-Au(iii) complexes were synthesized and encapsulated into a triblock copolymer to form micelles. Electron microscopy and electron energy loss spectroscopy techniques were used to observe the strong interaction between gold and doped graphene. Density-functional theory calculations supported the experimental findings.
NANOSCALE ADVANCES
(2023)
Article
Chemistry, Physical
Lei Wang, Lei Zhang, Luyao Zhang, Yulong Yun, Kun Wang, Boyuan Yu, Xin Zhao, Feng Yang
Summary: This study investigates the interface of hard-to-reduce silica-metal catalysts and reveals their behaviors. The Pt/SiO2 catalytic system shows enhanced stability and activity due to the changes in the interface structure under reactive conditions.
Article
Chemistry, Physical
Lei Wang, Lei Zhang, Luyao Zhang, Yulong Yun, Kun Wang, Boyuan Yu, Xin Zhao, Feng Yang
Summary: For the hard-to-reduce silica-metal catalyst, the interface structure and evolution under reactive conditions have been revealed. It was found that Si-0 at the Pt-SiO2 interface underwent reduction and further diffused into the near surface of Pt nanoparticles under H-2. This reconstructed interface with Si diffusion improved the sinter resistance and catalytic stability of the catalyst.
Article
Chemistry, Physical
Tejasvini Sharma, Naveen Kumar Tailor, Neha Choudhury, Dishant Kumar, Saurabh K. Saini, Anirban Mitra, Mahesh Kumar, Priyadarsi De, Soumitra Satapathi
Summary: Incorporating organic semiconductors in insulating polymer films has been widely used in optoelectronic devices. In this study, the excited state dynamics and spin physics of a model fluorescent organic dilute semiconductor were investigated. The results show that lowering the temperature leads to blue-shifted fluorescence emission and enhanced intensity, which is attributed to reduced charge carrier scattering at low temperature. In addition, additional higher energy peaks were observed at temperatures below 70 K, which are explained by exciton-phonon coupling.
Article
Chemistry, Physical
Songphol Kanjanachuchai, Thipusa Wongpinij, Chanan Euaruksakul, Pat Photongkam
Summary: By using in-situ spectromicroscopy, the sublimation and recrystallization of InP(100) surfaces were real-time followed and controlled, revealing the presence of an ultrathin In layer along with microscopic In droplets. Through controlled exposure to ultraviolet photons, the ultrathin In layer can be induced to dewet, leading to redistribution of atoms and formation of ultrathin layers around existing droplets. Heating the layers causes them to expand and overlap, returning the surface to its original state prior to dewetting.
APPLIED SURFACE SCIENCE
(2021)
Article
Multidisciplinary Sciences
Pei Jiang Low, Weibin Chu, Zhaogang Nie, Muhammad Shafiq Bin Mohd Yusof, Oleg Prezhdo, Zhi-Heng Loh
Summary: Despite decades of study, a unified picture of the electronic relaxation dynamics of ionized liquid water has remained unclear. In this research, we used experimental and simulation techniques to reveal the sequential relaxation of an excess electron injected into the conduction band of ionized liquid water. We also identified an intermediate excited state and discovered the involvement of different vibrational modes in the electronic relaxation process. Our findings provide a detailed atomistic picture of the electronic relaxation dynamics of ionized liquid water with unprecedented time resolution.
NATURE COMMUNICATIONS
(2022)
Article
Physics, Multidisciplinary
Dai Aoki, Hironori Sakai, Petr Opletal, Yoshifumi Tokiwa, Jun Ishizuka, Youichi Yanase, Hisatomo Harima, Ai Nakamura, Dexin Li, Yoshiya Homma, Yusei Shimizu, Georg Knebel, Jacques Flouquet, Yoshinori Haga
Summary: This study reports the first observation of the de Haas-van Alphen (dHvA) effect in the novel spin-triplet superconductor UTe2. The researchers found that UTe2 has two types of cylindrical Fermi surfaces with strong corrugation, and the angular dependence of the dHvA frequencies is in good agreement with the calculated results.
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN
(2022)
Review
Multidisciplinary Sciences
Kun Jiang, Tao Wu, Jia-Xin Yin, Zhenyu Wang, M. Zahid Hasan, Stephen D. Wilson, Xianhui Chen, Jiangping Hu
Summary: This review discusses the recent progress on the experimental and theoretical studies of kagome superconductors AV(3)Sb(5), including the electronic properties, charge density wave state, time-reversal symmetry breaking, and superconducting properties. The authors aim to stimulate an expanded search for unconventional kagome superconductors.
NATIONAL SCIENCE REVIEW
(2023)
Article
Physics, Multidisciplinary
Xingyu Jiang, Mingyang Qin, Xinjian Wei, Li Xu, Jiezun Ke, Haipeng Zhu, Ruozhou Zhang, Zhanyi Zhao, Qimei Liang, Zhongxu Wei, Zefeng Lin, Zhongpei Feng, Fucong Chen, Peiyu Xiong, Jie Yuan, Beiyi Zhu, Yangmu Li, Chuanying Xi, Zhaosheng Wang, Ming Yang, Junfeng Wang, Tao Xiang, Jiangping Hu, Kun Jiang, Qihong Chen, Kui Jin, Zhongxian Zhao
Summary: Superconductivity is related to the strange-metal state, and the resistivity in the strange metal significantly depends on the superconducting transition temperature. Unconventional superconductors usually exhibit a linear temperature dependence of resistivity (T-linear) in the low-temperature limit. The understanding of the relationship between the strange metal and superconductivity is crucial for further theoretical development, but comprehensive studies are lacking due to the difficulty in controlling the superconducting state. In this study, a typical strange-metal behavior, T-linear resistivity, linear-in-field magnetoresistance, and universal scaling of magnetoresistance, is observed in FeSe. The relationship between the T-linear resistivity coefficient and the critical temperature suggests a universal mechanism underlying T-linear resistivity and unconventional superconductivity.
Article
Instruments & Instrumentation
J. Correa, M. Mehrjoo, R. Battistelli, F. Lehmkuehler, A. Marras, C. B. Wunderer, T. Hirono, V Felk, F. Krivan, S. Lange, I Shevyakov, V. Vardanyan, M. Zimmer, M. Hoesch, K. Bagschik, N. Guerrini, B. Marsh, I Sedgwick, G. Cautero, L. Stebel, D. Giuressi, R. H. Menk, A. Greer, T. Nicholls, W. Nichols, U. Pedersen, P. Shikhaliev, N. Tartoni, H. J. Hyun, S. H. Kim, S. Y. Park, K. S. Kim, F. Orsini, F. J. Iguaz, F. Buettner, B. Pfau, E. Ploenjes, K. Kharitonov, M. Ruiz-Lopez, R. Pan, S. Gang, B. Keitel, H. Graafsma
Summary: The PERCIVAL detector is a CMOS imager specifically designed for the soft X-ray regime. It has been used in various user experiments, such as ptychography, holographic imaging, and X-ray photon correlation spectroscopy. The detector has shown remarkable performance in terms of spatial resolution and frame rate, making it an attractive option for soft X-ray science.
JOURNAL OF SYNCHROTRON RADIATION
(2023)
Article
Materials Science, Multidisciplinary
Yipeng An, Juncai Chen, Zhengxuan Wang, Jie Li, Shijing Gong, Chunlan Ma, Tianxing Wang, Zhaoyong Jiao, Ruqian Wu, Jiangping Hu, Wuming Liu
Summary: In this study, a new kagome magnesium triboride (MgB3) superconductor is predicted, with a calculated critical temperature of about 12.2 K and 15.4 K under external stress, which is potentially the highest among the reported diverse kagome-type superconductors. Various exotic physical properties of the system, including van Hove singularity, flat-band, multiple Dirac points, and nontrivial topology, are revealed. The topological and nodal superconducting nature of MgB3 is unveiled using a recently developed symmetry indicators method. This study suggests that MgB3 can serve as a new platform to explore exotic physics in the kagome structure and search for more superconductors and topological materials with XY3-type kagome lattice.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Chemistry, Inorganic & Nuclear
Ying Zhou, Long Chen, Yuxin Wang, Jinfeng Zhu, Zhongnan Guo, Chen Liu, Zhiying Guo, ChinWei Wang, Han Zhang, Yulong Wang, Ke Liao, Youting Song, Jia-ou Wang, Dongliang Chen, Jie Ma, Jiangping Hu, Gang Wang
Summary: A new series of compounds, ANi5Bi5.6+delta (where A = K, Rb, and Cs), have been discovered with a quasi-one-dimensional (Q1D) [Ni5Bi5.6+delta]- double-walled column and a coaxial inner one-dimensional Bi atomic chain. The compounds exhibit metallic behaviors with strong electron correlation, and the Sommerfeld coefficient is enhanced with the increasing cationic radius. The substitution of Ni for Mn in ANi5Bi5.6+delta results in enhanced intercolumn distances and strong diamagnetic susceptibilities.
INORGANIC CHEMISTRY
(2023)
Article
Multidisciplinary Sciences
Yigui Zhong, Jinjin Liu, Xianxin Wu, Zurab Guguchia, J. -x. Yin, Akifumi Mine, Yongkai Li, Sahand Najafzadeh, Debarchan Das, Charles Mielke, Rustem Khasanov, Hubertus Luetkens, Takeshi Suzuki, Kecheng Liu, Xinloong Han, Takeshi Kondo, Jiangping Hu, Shik Shin, Zhiwei Wang, Xun Shi, Yugui Yao, Kozo Okazaki
Summary: The newly discovered kagome superconductors offer a promising platform to explore the interplay between band topology, electronic order, and lattice geometry. However, the nature of the superconducting ground state and the electron pairing symmetry in this system is still not well understood. In this study, we directly observed a nodeless and nearly isotropic superconducting gap in the momentum space of two different kagome superconductors using high-resolution and low-temperature angle-resolved photoemission spectroscopy. The unique properties of the superconducting gap are independent of charge order in the normal state. This comprehensive characterization provides essential information about the electron pairing symmetry in kagome superconductors and advances our understanding of superconductivity and intertwined electronic orders in quantum materials.
Article
Physics, Multidisciplinary
Edgar Abarca Morales, Gesa-R. Siemann, Andela Zivanovic, Philip A. E. Murgatroyd, Igor Markovic, Brendan Edwards, Chris A. Hooley, Dmitry A. Sokolov, Naoki Kikugawa, Cephise Cacho, Matthew D. Watson, Timur K. Kim, Clifford W. Hicks, Andrew P. Mackenzie, Phil D. C. King
Summary: We present the evolution of the electronic structure at the surface of Sr2RuO4 under large in-plane uniaxial compression, resulting in anisotropic B1g strains. Using angle-resolved photoemission, we observe a sequence of Lifshitz transitions that reshape the electronic structure and van Hove singularities on the surface. Our study reveals the nature of structural distortions at oxide surfaces and the possibility of controlling the density of state singularities for the realization of collective states at the Sr2RuO4 surface.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
A. Garrison Linn, Peipei Hao, Kyle N. Gordon, Dushyant Narayan, Bryan S. Berggren, Nathaniel Speiser, Sonka Reimers, Richard P. Campion, Vit Novak, Sarnjeet S. Dhesi, Timur K. Kim, Cephise Cacho, Libor Smejkal, Tomas Jungwirth, Jonathan D. Denlinger, Peter Wadley, Daniel S. Dessau
Summary: This study reports direct measurements of the electronic structure of tetragonal CuMnAs thin films using ARPES, including Fermi surfaces and energy-wavevector dispersions. After correcting for a chemical potential shift, there is excellent agreement between the experimental results and theoretical calculations. 2x1 surface reconstructions are also observed in low energy electron diffraction and ARPES. This work emphasizes the importance of controlling the chemical potential in tetragonal CuMnAs to explore and exploit tunable Dirac fermions.
NPJ QUANTUM MATERIALS
(2023)
Article
Physics, Applied
Moritz Hoesch, Olena Fedchenko, Mao Wang, Christoph Schlueter, Dmitrii Potorochin, Katerina Medjanik, Sergey Babenkov, Anca S. Ciobanu, Aimo Winkelmann, Hans-Joachim Elmers, Shengqiang Zhou, Manfred Helm, Gerd Schoenhense
Summary: Multiple dopant configurations of Te impurities in silicon are investigated using various techniques. Strong chemical core level shifts distinguish these configurations from isolated impurities. Multi-Te configurations, such as dimers or Te ions surrounding a vacancy, are clearly identified. The results contribute to understanding the exceptional activation of free charge carriers in hyperdoping of chalcogens in silicon.
APPLIED PHYSICS LETTERS
(2023)
Article
Microscopy
O. Tkach, T. -P. Vo, O. Fedchenko, K. Medjanik, Y. Lytvynenko, S. Babenkov, D. Vasilyev, Q. L. Nguyen, T. R. F. Peixoto, A. Gloskowskii, C. Schlueter, S. Chernov, M. Hoesch, D. Kutnyakhov, M. Scholz, L. Wenthaus, N. Wind, S. Marotzke, A. Winkelmann, K. Rossnagel, J. Minar, H. -J. Elmers, G. Schonhense
Summary: X-ray photoelectron diffraction (XPD) is a powerful technique that provides detailed structural information of solids and thin films, complementing electronic structure measurements. XPD patterns exhibit pronounced circular dichroism in the angular distribution (CDAD) with asymmetries up to 80%, alongside rapid variations on a small kll-scale. Measurements with circularly-polarized hard X-rays confirm that core-level CDAD is a general phenomenon independent of atomic number.
Article
Multidisciplinary Sciences
Kifu Kurokawa, Shunsuke Isono, Yoshimitsu Kohama, So Kunisada, Shiro Sakai, Ryotaro Sekine, Makoto Okubo, Matthew. D. D. Watson, Timur. K. K. Kim, Cephise Cacho, Shik Shin, Takami Tohyama, Kazuyasu Tokiwa, Takeshi Kondo
Summary: By studying the inner CuO2 planes of a six-layered compound, the authors find that even the slightest amount of carriers can turn a Mott insulating state into a metallic state with long-lived quasiparticles. Furthermore, they observe a phase transition from the superconducting to the metallic states at 4% doping.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
R. Z. Xu, X. Du, J. S. Zhou, X. Gu, Q. Q. Zhang, Y. D. Li, W. X. Zhao, F. W. Zheng, M. Arita, K. Shimada, T. K. Kim, C. Cacho, Y. F. Guo, Z. K. Liu, Y. L. Chen, L. X. Yang
Summary: Using high-resolution angle-resolved photoemission spectroscopy and ab initio calculation, we systematically investigate the electronic structure of TaTe4 and observe a CDW gap as large as 290 meV at 26 K, which persists up to 500 K. The CDW-modulated band structure shows a complex reconstruction that closely correlates with the lattice distortion. Our ab initio calculation reveals that the large CDW gap mainly opens in the electronic states with out-of-plane orbital components, while in-gap metallic states originate from in-plane orbitals, suggesting an orbital texture that couples with the CDW order.
NPJ QUANTUM MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Q. Q. Zhang, Y. Shi, K. Y. Zhai, W. X. Zhao, X. Du, J. S. Zhou, X. Gu, R. Z. Xu, Y. D. Li, Y. F. Guo, Z. K. Liu, C. Chen, S. K. Mo, T. K. Kim, C. Cacho, J. W. Yu, W. Li, Y. L. Chen, Jiun-Haw Chu, L. X. Yang
Summary: In this paper, the electronic structure and transport properties of EuTe4 were investigated using high-resolution angle-resolved photoemission spectroscopy (ARPES), magnetoresistance (MR) measurements, and scanning tunneling microscopy (STM). A CDW gap of approximately 200 meV was observed at low temperatures, which persists up to 400 K, suggesting a higher transition temperature. The negatively large MR at low temperatures may be related to the canting of magnetically ordered Eu spins.
Article
Materials Science, Multidisciplinary
Yi Zhang, Yuhao Gu, Hongming Weng, Kun Jiang, Jiangping Hu
Summary: We investigate the strong electron-electron correlation effects in two-dimensional van der Waals materials Nb3X8 (X = Cl, Br, I). The monolayers Nb3X8 are close to the strong correlation limit and can be described by a half-filled single band Hubbard model with U/W ratio approximating to 5-10. Mott and magnetic transitions are calculated using the slave boson mean-field theory, and a dx2-y2 + idxy superconducting pairing instability is found upon doping the Mott state. A tunable bilayer Hubbard system is also constructed for two sliding Nb3X8 layers, showing a crossover between band insulator and Mott insulator.
Article
Materials Science, Multidisciplinary
Kun Jiang, Ziyue Qi, Hongming Weng, Jiangping Hu
Summary: In this study, we examine the properties of obstructed atomic insulators under correlation and find that the obstruction properties persist even at high correlation levels. This suggests that the obstructed atomic insulator phase can transition to its Mott phase seamlessly without undergoing a Mott transition.
