Article
Materials Science, Multidisciplinary
Yuya Nagase, Masahiro Manago, Junichi Hayashi, Keiki Takeda, Hideki Tou, Eiichi Matsuoka, Hitoshi Sugawara, Hisatomo Harima, Hisashi Kotegawa
Summary: We have synthesized and measured the 75As nuclear quadrupole resonance (NQR) for the noncentrosymmetric superconductor CaPtAs with a superconducting transition temperature Tc of -1.5 K. Two different forms of CaPtAs, a high-temperature tetragonal form and a low-temperature form consistent with the orthorhombic structure of CaPtP, were discovered during synthesis. The 75As NQR measurement for the tetragonal CaPtAs revealed an obvious coherence peak in the nuclear spin-lattice relaxation rate 1/T1 below Tc, indicating that CaPtAs is a multigap superconductor with a large s-wave component.
Article
Physics, Multidisciplinary
Chao Mu, Qiangwei Yin, Zhijun Tu, Chunsheng Gong, Ping Zheng, Hechang Lei, Zheng Li, Jianlin Luo
Summary: We conducted Sb-121 nuclear quadrupole resonance (NQR) measurements on the kagome superconductor CsV3Sb5 with T(c) of 2.5 K. The Sb-121 NQR spectra split after a charge density wave (CDW) transition at 94 K, indicating the presence of a commensurate CDW state. The coexistence of the high temperature phase and CDW phase between 91 K and 94 K suggests a first order phase transition. The CDW order exhibits a tri-hexagonal deformation with a lateral shift between adjacent kagome layers, consistent with a 2 x 2 x 2 superlattice modulation. The superconducting state coexists with CDW order and shows conventional s-wave behavior in the bulk state.
Article
Physics, Multidisciplinary
Sachith E. Dissanayake, Masaaki Matsuda, Kazuyoshi Yoshimi, Shusuke Kasamatsu, Feng Ye, Songxue Chi, William Steinhardt, Gilberto Fabbris, Sara Haravifard, Jinguang Cheng, Jiaqiang Yan, Jun Gouchi, Yoshiya Uwatoko
Summary: MnP is a metal that exhibits paramagnetic, ferromagnetic, and helical magnetic phases, and shows superconductivity under high pressure. The magnetic transitions and quantum critical behavior play a crucial role in this material. Through experimental and theoretical calculations, the exchange interactions in the magnetic ground state adjacent to the superconducting phase have been elucidated, which is critical for understanding the pairing mechanism of unconventional superconductivity in MnP.
PHYSICAL REVIEW RESEARCH
(2023)
Article
Multidisciplinary Sciences
Aaron Chronister, Andrej Pustogow, Naoki Kikugawa, Dmitry A. Sokolov, Fabian Jerzembeck, Clifford W. Hicks, Andrew P. Mackenzie, Eric D. Bauer, Stuart E. Brown
Summary: This study explores the superconducting property of Sr2RuO4 and distinguishes different pairing scenarios. By comparing the magnetic susceptibility measurements and specific heat measurements, as well as field-dependent 17O Knight shift measurements, the researchers were able to differentiate between condensate contribution and quasiparticle contribution.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Computer Science, Artificial Intelligence
Cristian Monea
Summary: This paper proposes the use of deep learning techniques to enhance the performance of nuclear quadrupole resonance detection. A new feature set for signal classification is introduced, and high-performance solutions are selected, adapted and implemented. Comparative analysis on a real data set shows that AlexNet outperforms other algorithms in terms of detection accuracy.
EXPERT SYSTEMS WITH APPLICATIONS
(2021)
Article
Energy & Fuels
Fuyong Wang, Fanchao Zeng, Lu Wang, Xianmu Hou, Hui Cheng, Jian Gao
Summary: This study analyzed the fractal characteristics of pore spaces in tight sandstones from the Ordos Basin in China, using NMR and RCP techniques. It showed that the fractal dimensions of pore spaces with movable fluids were negatively correlated with permeability and reservoir quality index, with fractal dimensions approaching 3 indicating less favorable petrophysical properties. Different fractal models were compared for calculating fractal dimensions, with the 3D capillary model found to be the most accurate for evaluating tight sandstone properties.
Article
Materials Science, Multidisciplinary
H. Chudo, M. Matsuo, S. Maekawa, E. Saitoh
Summary: Using the rotating nuclear quadrupole resonance (NQR) method, we observed the Barnett field, rotational Doppler effect, and Berry phase, and studied the different NQR line splittings in various setups. Analyzing these spectral structures allowed us to clarify the origins of NQR line splittings and discuss the relationship between rotational Doppler effect, Barnett field effect, and Berry phase. Additionally, we provided clear evidence of the differences between rotational Doppler effect and Barnett field, and the equivalence of Barnett field and Berry phase.
Article
Computer Science, Artificial Intelligence
Cristian Monea
Summary: This paper proposes a method for nuclear quadrupole resonance signal detection using deep learning and transfer learning techniques, and introduces two denoising architectures. Through experiments, it is demonstrated that this method can achieve high detection accuracy under low signal-to-noise ratio conditions.
EXPERT SYSTEMS WITH APPLICATIONS
(2022)
Article
Chemistry, Physical
Yuta Hibe, Kazuyuki Takeda
Summary: This article extends the analysis of spin-lattice relaxation in nuclear quadrupole resonance (NQR) of spin-5/2 to account for the distribution of non equilibrium populations created by a resonant radio-frequency pulse. The proposed theory is applicable to axially symmetric electric field gradient tensor and is tested in the context of spin-lattice relaxation of (127I) NQR in polycrystalline pyridine iodine monochloride measured at 469 MHz at 77 K.
CHEMICAL PHYSICS LETTERS
(2022)
Article
Optics
Akira Kofuji, Robert Peters
Summary: High-order harmonic generation (HHG) is a widely studied nonlinear optical phenomenon with potential applications. This study focuses on the unconventional gap dependence of HHG in the Mott insulator Ca2RuO4, which cannot be explained by semiclassical theory. Numerical analysis of two-level systems shows that HHG strength increases when the Rabi frequency is large compared to the gap width. The relaxation and scattering of electrons also affect the visibility of this gap dependence. This study reveals a universal scaling law for HHG enhancement rate regardless of the driving frequency.
Article
Engineering, Electrical & Electronic
Yunxing Song, Hengkang Zheng, Mengyu Liu, Houxiu Xiao, Xiaotao Han, Liang Li
Summary: This paper presents a new hybrid global optimization method for designing a high-frequency gyrotron superconducting magnet. The method includes three routines to obtain different types of coil designs and the results show high efficiency and applicability to other superconducting magnet designs.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2022)
Article
Mathematics, Interdisciplinary Applications
Mariam Sultana, Uroosa Arshad, Muhammad Khalid, Ali Akgul, Wedad Albalawi, Heba Y. Zahran
Summary: This research presents a new iterative predictor-corrector algorithm for solving fractional nuclear magnetic resonance flow equations. The algorithm shows higher accuracy and requires less computational time compared to previous numerical methods. It has a great potential for application in other chaotic systems of fractional differential equations.
FRACTAL AND FRACTIONAL
(2022)
Article
Materials Science, Multidisciplinary
Keishi Sunami, Tomohiro Baba, Kazuya Miyagawa, Sachio Horiuchi, Kazushi Kanoda
Summary: In this study, microscopic lattice states in TTF-BA were investigated using Br-79-NQR spectroscopy, revealing a ferroelectric transition with lattice dimerization and extraordinary lattice fluctuations. The emergence of these fluctuations, likely associated with polar fluctuations, explains the anomalously suppressed paramagnetic spin susceptibility observed prior to the nonmagnetic ferroelectric order.
Article
Physics, Multidisciplinary
A. F. Fang, R. Zhou, H. Tukada, J. Yang, Z. Deng, X. C. Wang, C. Q. Jin, Guo-Qing Zheng
Summary: This study investigates the superconducting properties of LiFeP and LiFeAs through nuclear magnetic resonance (NMR) studies, revealing differences in their superconducting behaviors. The saturation of λ(L) in LiFeAs indicates nodeless superconducting gaps, while the absence of saturation in LiFeP suggests the presence of nodes in the superconducting gap function. Strong spin fluctuations with diffusive characteristics are also observed in LiFeP, similar to some cuprate high temperature superconductors.
Article
Chemistry, Multidisciplinary
Aliki Moysiadi, Francesco Giustiniano, Andrew M. R. Hall, Topaz A. A. Cartlidge, Lynda J. Brown, Giuseppe Pileio
Summary: Hyperpolarization techniques enhance NMR signal but face limitations due to the short lifetime of hyperpolarized spin order. Prolonged storage of spin polarization can be achieved using long-lived spin states and low viscosity liquid-CO2 solutions. This extended storage time in liquid-CO2 solutions opens up possibilities for new storage experiments in the future.
FRONTIERS IN CHEMISTRY
(2021)
