Bohm potential and electron spin are very important quantum effects in quantum plasma. In certain circumstances, they may have important influences on the interaction of electromagnetic wave and plasma. In this paper, we make a comparison of spin force and Bohm potential force in Gaussian laser pulse–magnetized quantum plasma, and clarify which force plays the main role under different conditions. It is shown that for long Gaussian pulse, which force will prevail depends on the ratio of (lambda_{p}^{2}/L_{p}^{2}) and the normalized potential a. And for short Gaussian pulse, if a < 0.2, the Bohm potential force is greater than the spin force, and if a > 0.2, the spin force will dominate the Bohm potential force.
{"title":"Comparison of Spin Force and Bohm Potential Force in Laser Pulse–Magnetized Spin Plasma","authors":"Qiang-Lin Hu, Yan-Chao She, Wen Hu, Jin-Peng Xiao","doi":"10.7566/jpsj.93.034501","DOIUrl":"https://doi.org/10.7566/jpsj.93.034501","url":null,"abstract":"Bohm potential and electron spin are very important quantum effects in quantum plasma. In certain circumstances, they may have important influences on the interaction of electromagnetic wave and plasma. In this paper, we make a comparison of spin force and Bohm potential force in Gaussian laser pulse–magnetized quantum plasma, and clarify which force plays the main role under different conditions. It is shown that for long Gaussian pulse, which force will prevail depends on the ratio of <tex-math space=\"preserve\" version=\"MathJax\">(lambda_{p}^{2}/L_{p}^{2})</tex-math> and the normalized potential <i>a</i>. And for short Gaussian pulse, if <i>a</i> < 0.2, the Bohm potential force is greater than the spin force, and if <i>a</i> > 0.2, the spin force will dominate the Bohm potential force.","PeriodicalId":17304,"journal":{"name":"Journal of the Physical Society of Japan","volume":"6 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139656594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, we show several types of (semi)-rational solutions for the two dimensional Mel’nikov equation. We derive multi-breather wave solutions. They present the oblique breathers, homoclinic orbits and their mixtures under two parameter constraints. We also obtain the general high-order lump solutions by employing the Schur polynomials. When internal parameters a2m+1 are large, the patterns display the polygons containing lower-order lump pattern in the central region together with possible multiple fundamental lumps in the outer region. When time t is large, two types of lump patterns are presented by considering the prediction solutions. The first type of lump patterns contain fundamental lumps with triangular shapes. The second type of lump patterns contain fundamental lumps with non-triangular shapes in the outer region, together with possible fundamental lumps with triangular shapes in the inner region. Furthermore, we construct the semi-rational solutions to exhibit the fascinating processes of fusion and fission between lumps and line solitons. These solutions should be of great interest in a variety of high-dimensional multi-component systems.
在这项工作中，我们展示了二维梅尔尼科夫方程的几种（半）有理解。我们推导了多呼吸波解。在两个参数约束下，它们呈现出斜呼吸波、同轴轨道及其混合物。我们还利用舒尔多项式获得了一般的高阶肿块解。当内部参数 a2m+1 较大时，图案显示出包含中心区域低阶块状图案的多边形，以及外围区域可能存在的多个基本块状图案。当时间 t 较大时，考虑到预测解，会出现两种肿块模式。第一种块状模式包含三角形的基本块。第二种肿块模式包含外围区域非三角形的基本肿块，以及内部区域可能存在的三角形基本肿块。此外，我们还构建了半理性解，以展示块体与线孤子之间的奇妙融合与裂变过程。这些解在各种高维多组分系统中都会引起极大兴趣。
{"title":"General Multi-Breather, High-Order Lump and Semi-Rational Solutions of the (2 + 1)-Dimensional Mel’nikov Equation","authors":"Xue-Wei Yan, Yong Chen, Xiu-Bin Wang, Shou-Fu Tian","doi":"10.7566/jpsj.93.024006","DOIUrl":"https://doi.org/10.7566/jpsj.93.024006","url":null,"abstract":"In this work, we show several types of (semi)-rational solutions for the two dimensional Mel’nikov equation. We derive multi-breather wave solutions. They present the oblique breathers, homoclinic orbits and their mixtures under two parameter constraints. We also obtain the general high-order lump solutions by employing the Schur polynomials. When internal parameters <i>a</i><sub>2</sub><i><sub>m</sub></i><sub>+1</sub> are large, the patterns display the polygons containing lower-order lump pattern in the central region together with possible multiple fundamental lumps in the outer region. When time <i>t</i> is large, two types of lump patterns are presented by considering the prediction solutions. The first type of lump patterns contain fundamental lumps with triangular shapes. The second type of lump patterns contain fundamental lumps with non-triangular shapes in the outer region, together with possible fundamental lumps with triangular shapes in the inner region. Furthermore, we construct the semi-rational solutions to exhibit the fascinating processes of fusion and fission between lumps and line solitons. These solutions should be of great interest in a variety of high-dimensional multi-component systems.","PeriodicalId":17304,"journal":{"name":"Journal of the Physical Society of Japan","volume":"15 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139646074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Layered nickelate R4Ni3O8 (R = La, Pr, Nd, Sm) is a candidate for a high-temperature superconductor because its crystal structure and electronic state are very similar to high-temperature superconducting cuprates. We have performed carrier tuning by chemical substitution to Ni sites to bring the electronic states of Ni closer to that of Cu in superconducting cuprates. We aim to substitute the specific Ni sites for carrier tuning without disturbing the NiO2 planes. In this study, we perform neutron powder diffraction experiments for the Pr4Ni3−xCoxO8 samples with doping Co for Ni sites to investigate the dopant distribution among the Ni sites. Rietveld analysis showed a tendency to preferentially occupy specific Ni sites when the doping level was low, but this is not the case for higher doping levels. We also analyzed the oxygen deficiency and found no oxygen deficiency in the NiO2 planes with lower chemical substitutions, indicating that the relatively undisturbed conduction planes were maintained. Finally, we discuss the effects of Co doping into NiO2 planes for the physical properties of R4Ni3O8.
层状镍酸盐 R4Ni3O8（R = La、Pr、Nd、Sm）是高温超导体的候选物质，因为它的晶体结构和电子状态与高温超导铜酸盐非常相似。我们通过对镍位点的化学置换进行了载流子调谐，使镍的电子状态更接近超导铜酸盐中铜的电子状态。我们的目标是在不干扰二氧化镍平面的情况下，替代特定的镍位点进行载流子调谐。在本研究中，我们对掺入 Co 的 Pr4Ni3-xCoxO8 样品进行了中子粉末衍射实验，以研究掺杂剂在 Ni 位点之间的分布。里特维尔德分析表明，当掺杂水平较低时，掺杂剂倾向于优先占据特定的镍位点，但当掺杂水平较高时，情况并非如此。我们还分析了缺氧情况，发现化学取代度较低的二氧化镍平面没有缺氧现象，这表明相对未受干扰的传导平面得以保持。最后，我们讨论了在 NiO2 平面中掺入 Co 对 R4Ni3O8 物理性质的影响。
{"title":"Neutron Diffraction Study of Layered Nickelates Pr4Ni3−xCoxO8 for High-Temperature Superconductor Candidate","authors":"Tomonori Miyatake, Yuki Wako, Ryota Abe, Satoru Tsukamoto, Masatomo Uehara","doi":"10.7566/jpsj.93.024709","DOIUrl":"https://doi.org/10.7566/jpsj.93.024709","url":null,"abstract":"Layered nickelate R<sub>4</sub>Ni<sub>3</sub>O<sub>8</sub> (R = La, Pr, Nd, Sm) is a candidate for a high-temperature superconductor because its crystal structure and electronic state are very similar to high-temperature superconducting cuprates. We have performed carrier tuning by chemical substitution to Ni sites to bring the electronic states of Ni closer to that of Cu in superconducting cuprates. We aim to substitute the specific Ni sites for carrier tuning without disturbing the NiO<sub>2</sub> planes. In this study, we perform neutron powder diffraction experiments for the Pr<sub>4</sub>Ni<sub>3−</sub><i><sub>x</sub></i>Co<i><sub>x</sub></i>O<sub>8</sub> samples with doping Co for Ni sites to investigate the dopant distribution among the Ni sites. Rietveld analysis showed a tendency to preferentially occupy specific Ni sites when the doping level was low, but this is not the case for higher doping levels. We also analyzed the oxygen deficiency and found no oxygen deficiency in the NiO<sub>2</sub> planes with lower chemical substitutions, indicating that the relatively undisturbed conduction planes were maintained. Finally, we discuss the effects of Co doping into NiO<sub>2</sub> planes for the physical properties of R<sub>4</sub>Ni<sub>3</sub>O<sub>8</sub>.","PeriodicalId":17304,"journal":{"name":"Journal of the Physical Society of Japan","volume":"397 2 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139587971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We investigate edge and bulk states in Weyl-orbit based quantum Hall effect by measuring a Corbino-type device fabricated from a topological Dirac semimetal (Cd1−xZnx)3As2 film. Clear quantum Hall plateaus are observed when measuring one-sided terminals of the Corbino-type device. This indicates that edge states of the Weyl-orbit quantum Hall effect form closed trajectories consisting of Fermi arcs and chiral zero modes independently on inner and outer sides. On the other hand, the bulk resistance does not diverge at fields where the quantum Hall plateau appears, suggesting that the Weyl orbits in the bulk region are not completely localized when applying electric current through the bulk region.
{"title":"Edge and Bulk States in Weyl-Orbit Quantum Hall Effect as Studied by Corbino Measurements","authors":"Yusuke Nakazawa, Ryosuke Kurihara, Masatoshi Miyazawa, Shinichi Nishihaya, Markus Kriener, Masashi Tokunaga, Masashi Kawasaki, Masaki Uchida","doi":"10.7566/jpsj.93.023706","DOIUrl":"https://doi.org/10.7566/jpsj.93.023706","url":null,"abstract":"We investigate edge and bulk states in Weyl-orbit based quantum Hall effect by measuring a Corbino-type device fabricated from a topological Dirac semimetal (Cd<sub>1−</sub><i><sub>x</sub></i>Zn<i><sub>x</sub></i>)<sub>3</sub>As<sub>2</sub> film. Clear quantum Hall plateaus are observed when measuring one-sided terminals of the Corbino-type device. This indicates that edge states of the Weyl-orbit quantum Hall effect form closed trajectories consisting of Fermi arcs and chiral zero modes independently on inner and outer sides. On the other hand, the bulk resistance does not diverge at fields where the quantum Hall plateau appears, suggesting that the Weyl orbits in the bulk region are not completely localized when applying electric current through the bulk region.","PeriodicalId":17304,"journal":{"name":"Journal of the Physical Society of Japan","volume":"334 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139587547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The peeling–ballooning (P–B) mode has been thought to play an essential role in causing the type-I edge-localized modes (ELMs) in the H-mode plasmas, although firm experimental evidences of the P–B mode as a cause of Type-I ELMs have not been provided. In this letter, we examine the dynamical evolution of the P–B mode when the plasma parameters come across the linear stability boundary. It is noted that the P–B mode model has some limitations to explain all of the trigger of Type-I ELMs.
剥离-膨胀（P-B）模式一直被认为在导致H模式等离子体中的I型边缘定位模式（ELM）中扮演着重要角色，尽管P-B模式作为I型ELM的成因还没有确切的实验证据。在这封信中，我们研究了当等离子体参数跨越线性稳定边界时 P-B 模式的动力学演变。我们注意到，P-B 模式模型在解释 I 型 ELM 的所有触发因素方面有一定的局限性。
{"title":"On the Role of Peeling–Ballooning Mode in Triggering the Type-I ELMs","authors":"Kimitaka Itoh, Kensaku Kamiya","doi":"10.7566/jpsj.93.023501","DOIUrl":"https://doi.org/10.7566/jpsj.93.023501","url":null,"abstract":"The peeling–ballooning (P–B) mode has been thought to play an essential role in causing the type-I edge-localized modes (ELMs) in the H-mode plasmas, although firm experimental evidences of the P–B mode as a cause of Type-I ELMs have not been provided. In this letter, we examine the dynamical evolution of the P–B mode when the plasma parameters come across the linear stability boundary. It is noted that the P–B mode model has some limitations to explain all of the trigger of Type-I ELMs.","PeriodicalId":17304,"journal":{"name":"Journal of the Physical Society of Japan","volume":"323 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139555135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We report the synthesis, electronic properties, and electronic states of Zr6MTe2 (M = Cr, Mn, Fe, and Co), which is isostructural to a recently discovered superconductor family Sc6MTe2. Based on the electrical resistivity and heat capacity data measured at low temperatures, Zr6FeTe2 is found to show bulk superconductivity below Tc = 0.76 K. Zr6CoTe2 also exhibited zero resistivity due to superconductivity below 0.13 K. In contrast, Zr6+δMn1−δTe2 does not show superconductivity but instead exhibits strong magnetism, which most likely prevents the formation of superconductivity in this material. The electronic properties and electronic states of Zr6MTe2 are discussed in comparison with those of Sc6MTe2.
{"title":"Superconductivity in Ternary Zirconium Telluride Zr6MTe2 with 3d Transition Metals","authors":"Haruka Matsumoto, Youichi Yamakawa, Ryutaro Okuma, Daisuke Nishio-Hamane, Yoshihiko Okamoto","doi":"10.7566/jpsj.93.023705","DOIUrl":"https://doi.org/10.7566/jpsj.93.023705","url":null,"abstract":"We report the synthesis, electronic properties, and electronic states of Zr<sub>6</sub>MTe<sub>2</sub> (M = Cr, Mn, Fe, and Co), which is isostructural to a recently discovered superconductor family Sc<sub>6</sub>MTe<sub>2</sub>. Based on the electrical resistivity and heat capacity data measured at low temperatures, Zr<sub>6</sub>FeTe<sub>2</sub> is found to show bulk superconductivity below <i>T</i><sub>c</sub> = 0.76 K. Zr<sub>6</sub>CoTe<sub>2</sub> also exhibited zero resistivity due to superconductivity below 0.13 K. In contrast, Zr<sub>6+</sub><i><sub>δ</sub></i>Mn<sub>1−</sub><i><sub>δ</sub></i>Te<sub>2</sub> does not show superconductivity but instead exhibits strong magnetism, which most likely prevents the formation of superconductivity in this material. The electronic properties and electronic states of Zr<sub>6</sub>MTe<sub>2</sub> are discussed in comparison with those of Sc<sub>6</sub>MTe<sub>2</sub>.","PeriodicalId":17304,"journal":{"name":"Journal of the Physical Society of Japan","volume":"5 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139554838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We first report that the seismic time-sequence data from around the world, excluding major earthquakes, consistently yield the power spectral density inversely proportional to the frequency f. This is the 1/f fluctuation that appears ubiquitously in nature. We investigate the origin of this 1/f fluctuation based on our recent proposal: 1/f noise is amplitude modulation and demodulation. We hypothesize that the amplitude modulation is linked to resonance with Earth’s Free Oscillations (EFO), with demodulation occurring during fault ruptures. We provide partial validation of this hypothesis through an analysis of EFO eigenmodes. Additionally, we outline potential methods for the future verification of our theory relating 1/f fluctuations to EFO.
{"title":"Seismic 1/f Fluctuations from Amplitude Modulated Earth’s Free Oscillation","authors":"Akika Nakamichi, Manaya Matsui, Masahiro Morikawa","doi":"10.7566/jpsj.93.024004","DOIUrl":"https://doi.org/10.7566/jpsj.93.024004","url":null,"abstract":"We first report that the seismic time-sequence data from around the world, excluding major earthquakes, consistently yield the power spectral density inversely proportional to the frequency <i>f</i>. This is the 1/<i>f</i> fluctuation that appears ubiquitously in nature. We investigate the origin of this 1/<i>f</i> fluctuation based on our recent proposal: 1/<i>f</i> noise is amplitude modulation and demodulation. We hypothesize that the amplitude modulation is linked to resonance with Earth’s Free Oscillations (EFO), with demodulation occurring during fault ruptures. We provide partial validation of this hypothesis through an analysis of EFO eigenmodes. Additionally, we outline potential methods for the future verification of our theory relating 1/<i>f</i> fluctuations to EFO.","PeriodicalId":17304,"journal":{"name":"Journal of the Physical Society of Japan","volume":"8 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139554833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We present the results of nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) measurements on the layered tin pnictide superconductors NaSn2As2 (the superconducting transition temperature Tc = 1.3 K) and Na1−xSn2P2 (Tc = 2.0 K). In NaSn2As2, a broad 75As NQR spectrum indicates a large charge distribution at the As site, and a broad 119Sn NMR spectrum indicates a distributed local density of states (DOS) at the Sn site. Almost the same level of microscopic disorder in the electronic state is also found at the Sn site in Na1−xSn2P2 as well. These results clearly indicate the presence of a local atomic disorder in these superconductors. We have also measured the nuclear spin–lattice relaxation rate 1/T1 to gain insight into the partial DOS at each site. Our NMR/NQR results are consistent with previous band calculations, indicating that Na deficiency results in an increase in the DOS at the Fermi energy (EF) due to the decrease in EF. The agreement between the experimental and band calculation results makes it more plausible that the increase in the Tc of Na1−xSn2P is due to the increase in the DOS at EF caused by the Na deficiency. This study thus demonstrates that NMR/NQR measurements can be a very effective tool in revealing the local electronic structure of materials by comparing experimental results with theoretical band calculations.
我们展示了对层状锡镍镉超导体 NaSn2As2（超导转变温度 Tc = 1.3 K）和 Na1-xSn2P2（Tc = 2.0 K）的核磁共振（NMR）和核四极共振（NQR）测量结果。在 NaSn2As2 中，宽阔的 75As NQR 光谱表明 As 位点存在大量电荷分布，而宽阔的 119Sn NMR 光谱则表明 Sn 位点存在分布式局部状态密度 (DOS)。在 Na1-xSn2P2 中的锡位点也发现了几乎相同程度的电子态微观无序。这些结果清楚地表明这些超导体中存在局部原子无序。我们还测量了核自旋-晶格弛豫速率 1/T1，以深入了解每个位点的部分 DOS。我们的 NMR/NQR 结果与之前的能带计算结果一致，表明 Na 的缺乏会导致费米能（EF）处的 DOS 因 EF 的降低而增加。实验结果与能带计算结果之间的一致性使得 Na1-xSn2P Tc 的增加更有可能是由于 Na 的缺乏导致了 EF 处 DOS 的增加。因此，这项研究表明，通过比较实验结果和理论能带计算结果，核磁共振/NQR 测量是揭示材料局部电子结构的一种非常有效的工具。
{"title":"Site-Selective NMR/NQR Study on Layered Tin Pnictide Superconductor NaSn2Pn2 (Pn = P and As)","authors":"Shota Nakanishi, Yusuke Nakai, Yosuke Goto, Yoshikazu Mizuguchi, Takuto Fujii, Takeshi Mito","doi":"10.7566/jpsj.93.023703","DOIUrl":"https://doi.org/10.7566/jpsj.93.023703","url":null,"abstract":"We present the results of nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) measurements on the layered tin pnictide superconductors NaSn<sub>2</sub>As<sub>2</sub> (the superconducting transition temperature <i>T</i><sub>c</sub> = 1.3 K) and Na<sub>1−</sub><i><sub>x</sub></i>Sn<sub>2</sub>P<sub>2</sub> (<i>T</i><sub>c</sub> = 2.0 K). In NaSn<sub>2</sub>As<sub>2</sub>, a broad <sup>75</sup>As NQR spectrum indicates a large charge distribution at the As site, and a broad <sup>119</sup>Sn NMR spectrum indicates a distributed local density of states (DOS) at the Sn site. Almost the same level of microscopic disorder in the electronic state is also found at the Sn site in Na<sub>1−</sub><i><sub>x</sub></i>Sn<sub>2</sub>P<sub>2</sub> as well. These results clearly indicate the presence of a local atomic disorder in these superconductors. We have also measured the nuclear spin–lattice relaxation rate 1/<i>T</i><sub>1</sub> to gain insight into the partial DOS at each site. Our NMR/NQR results are consistent with previous band calculations, indicating that Na deficiency results in an increase in the DOS at the Fermi energy (<i>E</i><sub>F</sub>) due to the decrease in <i>E</i><sub>F</sub>. The agreement between the experimental and band calculation results makes it more plausible that the increase in the <i>T</i><sub>c</sub> of Na<sub>1−</sub><i><sub>x</sub></i>Sn<sub>2</sub>P is due to the increase in the DOS at <i>E</i><sub>F</sub> caused by the Na deficiency. This study thus demonstrates that NMR/NQR measurements can be a very effective tool in revealing the local electronic structure of materials by comparing experimental results with theoretical band calculations.","PeriodicalId":17304,"journal":{"name":"Journal of the Physical Society of Japan","volume":"213 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139555116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We investigate the Hubbard model with the Rashba spin–orbit coupling on a square lattice. The Rashba spin–orbit coupling generates two-dimensional Weyl points in the band dispersion. In a system with edges along [11] direction, zero-energy edge states appear, while no edge state exists for a system with edges along an axis direction. The zero-energy edge states with a certain momentum along the edges are predominantly in the up-spin state on the right edge, while they are predominantly in the down-spin state on the left edge. Thus, the zero-energy edge states are helical. By using a variational Monte Carlo method for finite Coulomb interaction cases, we find that the Weyl points can move toward the Fermi level by the correlation effects. We also investigate the magnetism of the model by the Hartree–Fock approximation and discuss weak magnetic order in the weak-coupling region.
{"title":"Weyl Semimetallic State in the Rashba–Hubbard Model","authors":"Katsunori Kubo","doi":"10.7566/jpsj.93.024708","DOIUrl":"https://doi.org/10.7566/jpsj.93.024708","url":null,"abstract":"We investigate the Hubbard model with the Rashba spin–orbit coupling on a square lattice. The Rashba spin–orbit coupling generates two-dimensional Weyl points in the band dispersion. In a system with edges along [11] direction, zero-energy edge states appear, while no edge state exists for a system with edges along an axis direction. The zero-energy edge states with a certain momentum along the edges are predominantly in the up-spin state on the right edge, while they are predominantly in the down-spin state on the left edge. Thus, the zero-energy edge states are helical. By using a variational Monte Carlo method for finite Coulomb interaction cases, we find that the Weyl points can move toward the Fermi level by the correlation effects. We also investigate the magnetism of the model by the Hartree–Fock approximation and discuss weak magnetic order in the weak-coupling region.","PeriodicalId":17304,"journal":{"name":"Journal of the Physical Society of Japan","volume":"52 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139517430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Layered BiS2-based superconductor La(O,F)BiS2 can exhibit superconductivity via carrier doping, and its superconducting properties can be changed by applying hydrostatic or chemical pressure through elemental substitution. Single-crystal LaO0.5F0.5BiS2 exhibits filamentary superconductivity with Tc of approximately 3 K. We found that the partial substitution of Bi with Sn in LaO0.5F0.5BiS2 induces a structural phase transition from the P4/nmm to P21/m structure. Bulk superconductivity with Tc of approximately 6 K emerged near this structural phase transition. We also observed filamentary superconductivity with Tc of approximately 8 K, which was approximately three times higher than that of the unsubstituted sample. This finding provides a new route for further increasing the superconducting transition temperature of this system.
基于 BiS2 的层状超导体 La(O,F)BiS2 可通过载流子掺杂表现出超导性，其超导特性可通过施加静水压力或化学压力来改变。我们发现，在 LaO0.5F0.5BiS2 中用 Sn 部分取代 Bi 会引起结构相变，即从 P4/nmm 结构转变为 P21/m 结构。在这一结构相变附近出现了 Tc 约为 6 K 的体超导现象。我们还观察到 Tc 约为 8 K 的丝状超导电性，比未取代样品的 Tc 高出约三倍。这一发现为进一步提高该系统的超导转变温度提供了新的途径。
{"title":"Enhancement of Superconductivity and Structural Instability by Sn Substitution in LaO0.5F0.5BiS2","authors":"Sora Kobayashi, Takeshi Hara, Kanako Noguchi, Tomoko Takeda, Ryosuke Kurihara, Atsushi Nomura, Satoshi Demura, Hiroshi Yaguchi, Hiroshi Sawa, Hideaki Sakata","doi":"10.7566/jpsj.93.024707","DOIUrl":"https://doi.org/10.7566/jpsj.93.024707","url":null,"abstract":"Layered BiS<sub>2</sub>-based superconductor La(O,F)BiS<sub>2</sub> can exhibit superconductivity via carrier doping, and its superconducting properties can be changed by applying hydrostatic or chemical pressure through elemental substitution. Single-crystal LaO<sub>0.5</sub>F<sub>0.5</sub>BiS<sub>2</sub> exhibits filamentary superconductivity with <i>T</i><sub>c</sub> of approximately 3 K. We found that the partial substitution of Bi with Sn in LaO<sub>0.5</sub>F<sub>0.5</sub>BiS<sub>2</sub> induces a structural phase transition from the <i>P</i>4/<i>nmm</i> to <i>P</i>2<sub>1</sub>/<i>m</i> structure. Bulk superconductivity with <i>T</i><sub>c</sub> of approximately 6 K emerged near this structural phase transition. We also observed filamentary superconductivity with <i>T</i><sub>c</sub> of approximately 8 K, which was approximately three times higher than that of the unsubstituted sample. This finding provides a new route for further increasing the superconducting transition temperature of this system.","PeriodicalId":17304,"journal":{"name":"Journal of the Physical Society of Japan","volume":"164 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139476463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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