Article
Materials Science, Multidisciplinary
Niels Henrik Aase, Asle Sudbo
Summary: This study investigates how spin fluctuations can induce superconductivity in a strongly correlated non-Fermi liquid with repulsive electronic interactions. By using a multichannel Luttinger liquid approach, the researchers find that spin-polarized triplet superconducting correlations persist in the system with sufficiently large interchain couplings.
Article
Multidisciplinary Sciences
S. Khim, J. F. Landaeta, J. Banda, N. Bannor, M. Brando, P. M. R. Brydon, D. Hafner, R. Kuechler, R. Cardoso-Gil, U. Stockert, A. P. Mackenzie, D. F. Agterberg, C. Geibel, E. Hassinger
Summary: Materials with multiple superconducting phases are rare, but CeRh2As2 has been discovered to exhibit two-phase unconventional superconductivity. The high critical field of 14 tesla in its high-field phase, combined with a transition between different superconducting phases in a c-axis magnetic field, is likely related to the local inversion-symmetry breaking and staggered Rashba coupling introduced at the cerium sites.
Article
Physics, Multidisciplinary
A. Sherman
Summary: In this study, the extended Hubbard model on a two-dimensional square lattice at half-filling is investigated using the strong coupling diagram technique. The first-order phase transition in the charge subsystem is found to occur at v = v(c) greater than or similar to U/4. The transition is characterized by an abrupt sign change in the zero-frequency charge susceptibility at the corner of the Brillouin zone. The alternating deviations of electron occupations from the mean value on neighboring sites have short-range order due to fluctuations.
Article
Materials Science, Multidisciplinary
Weiting Chen, Hanqin Ding, Jun Zhang
Summary: In this study, we analytically investigate the phase diagram of a one-dimensional half-filled extended Hubbard model with nearest neighboring four-electron interaction in the weak-coupling regime. Our results show that the additional four-electron coupling splits independent Gaussian and spin-gap transitions and also leads to the charge-gap transition.
RESULTS IN PHYSICS
(2022)
Article
Physics, Multidisciplinary
H. Huang, S-J Lee, Y. Ikeda, T. Taniguchi, M. Takahama, C-C Kao, M. Fujita, J-S Lee
Summary: The presence of a small concentration of in-plane Fe dopants in La1.87Sr0.13Cu0.99Fe0.01O4 is known to enhance stripelike spin and charge density wave (SDW and CDW) order, suppress the superconducting T-c, and induce highly two-dimensional superconducting correlations, which are argued to be signatures of a new form of superconducting order, the pair density wave (PDW) order. This two-dimensional superconducting fluctuation is strongly associated with the CDW stripe, and the PDW signature appears when the correlation length of the CDW stripe grows over eight times the lattice unit.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
A. Sherman
Summary: In this study, the extended Hubbard model on a two-dimensional square lattice is investigated using the strong coupling diagram technique. The phase diagrams for different parameters are obtained, showing the charge distribution and magnetic behavior, and revealing the manifestation of the Pomeranchuk effect.
Article
Materials Science, Multidisciplinary
Gao-Wei Qiu, Yi Zhou
Summary: Under the influence of a magnetic field, two weakly linked superconducting ultrathin films exhibit different superconducting states, with one characterized by staggered supercurrent loops and a superfluid density wave, and the other by uniform superfluid density. The phase transition between these two states falls within a specific universality class.
Article
Physics, Multidisciplinary
Ke Liu, Shuhui Yang, Weiqi Li, Tao Ying, Jianqun Yang, Xiudong Sun, Xingji Li
Summary: Using finite-temperature determinant quantum Monte Carlo algorithm, the study investigates the effective pairing susceptibility in the two-dimensional Hubbard model, identifying the dominant pairing channels in different parameter regimes. The dominant pairing is found to be d(x2-y2)-wave at half-filling, while in doping cases, the dominant channel may switch between d(x2-y2)-wave and d(xy)-wave.
Article
Physics, Multidisciplinary
Shuhui Yang, Tao Ying
Summary: The coexistence of superconductivity and charge inhomogeneity is observed in cuprate superconductors and the intercalated graphitic superconductor CaC6. This study simulates this system and examines the relationship between superconducting pairing and charge inhomogeneity. The findings suggest an optimal charge inhomogeneity for d+id-wave pairing and show a monotonic suppression of the pairing for other artificial charge inhomogeneities. The possible pi-phase shift induced by charge inhomogeneity is also explored.
FRONTIERS OF PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
A. Montorsi, U. Bhattacharya, Daniel Gonzalez-Cuadra, M. Lewenstein, G. Palumbo, L. Barbiero
Summary: The study explores higher-order topological crystalline phases in low-dimensional interacting quantum systems and interacting second-order topological insulating phases, showing distinct characteristics under strong interactions.
Article
Physics, Multidisciplinary
Alessio Zaccone
Summary: We present an analytical derivation of the volume fractions for random close packing in both 3D and 2D, and compare the derived values with those reported in the literature using different methods. The derivation suggests that random close packing corresponds to the onset of mechanical rigidity and is determined by the coordination number. The article also points out the possibility of achieving volume fractions above the maximum random jammed state by creating some order, with the coordination number at the fcc limit acting as a boundary condition.
PHYSICAL REVIEW LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Yan Xu, Hanqin Ding
Summary: The ground-state properties of a modified 1D Penson-Kolb-Hubbard model are discussed using the bosonization scheme and renormalization group analysis. The model exhibits charge-density-wave, spin-density-wave, and singlet superconductivity instabilities at quarter filling.
RESULTS IN PHYSICS
(2022)
Article
Physics, Condensed Matter
Shuhui Yang, Xingcan Liu, Weiqi Li, Jianqun Yang, Tao Ying, Xingji Li, Xiudong Sun
Summary: By studying the effect of periodically modulated hopping amplitudes on the d-wave pairing in the Hubbard model on a square lattice, it is found that the modulation enhances the d-wave pairing and there exists an optimal inhomogeneity.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Materials Science, Multidisciplinary
S. Holenstein, F. Hummel, Z. Guguchia, S. Kamusella, N. Barbero, H. Ogino, Z. Shermadini, R. Khasanov, A. Amato, T. Shiroka, H-H Klauss, E. Morenzoni, D. Johrendt, H. Luetkens
Summary: The relationship between magnetism and superconductivity in Sr2VO3FeAs under pressure undergoes a complex evolution, with a possible cooperative coupling between superconducting and magnetic orders as the pressure changes.
Article
Materials Science, Multidisciplinary
Yue Sun, Yongqiang Pan, Nan Zhou, Xiangzhuo Xing, Zhixiang Shi, Jinhua Wang, Zengwei Zhu, Akira Sugimoto, Toshikazu Ekino, Tsuyoshi Tamegai, Haruhisa Kitano
Summary: A systematic study was conducted on the superconducting and normal-state anisotropy of Fe1+yTe0.6Se0.4 single crystals with controlled excess Fe levels, revealing an increase in the anisotropy of effective mass with excess Fe. While the superconducting state shows almost isotropic behavior at low temperatures, a significant anisotropy is observed near T-c in the normal state. The discrepancy in anisotropies between the SC and normal states is attributed to the large anisotropy of scattering time tau(ab)/tau(c).
Article
Physics, Multidisciplinary
Hirofumi Sakakibara, Hidetomo Usui, Katsuhiro Suzuki, Takao Kotani, Hideo Aoki, Kazuhiko Kuroki
PHYSICAL REVIEW LETTERS
(2020)
Article
Materials Science, Multidisciplinary
Motoharu Kitatani, Liang Si, Oleg Janson, Ryotaro Arita, Zhicheng Zhong, Karsten Held
NPJ QUANTUM MATERIALS
(2020)
Review
Multidisciplinary Sciences
Taishi Chen, Takahiro Tomita, Susumu Minami, Mingxuan Fu, Takashi Koretsune, Motoharu Kitatani, Ikhlas Muhammad, Daisuke Nishio-Hamane, Rieko Ishii, Fumiyuki Ishii, Ryotaro Arita, Satoru Nakatsuji
Summary: The recent discoveries of large zero-field Hall and Nernst effects in antiferromagnets Mn3X (X=Sn, Ge) are considered fingerprints of magnetic Weyl nodes near the Fermi energy, highlighting the importance of magnetic topological states in condensed matter research. This review combines previous reports with new transport measurements on high-quality Mn3Sn and Mn3Ge single crystals, identifying magnetotransport signatures specific to chiral anomalies and planar Hall effect, suggesting the essential role of magnetic Weyl fermions in producing large transverse responses in the absence of magnetization.
NATURE COMMUNICATIONS
(2021)
Article
Physics, Multidisciplinary
Tohru Kawarabayashi, Yuya Inoue, Ryo Itagaki, Yasuhiro Hatsugai, Hideo Aoki
Summary: The robustness of zero-modes of two-dimensional Dirac fermions on a honeycomb lattice with Kekule bond ordering is examined numerically. The split n = 0 Landau levels in a magnetic field and the zero-modes generated by topological defects in the Kekule ordering exhibit anomalous robustness against disorder, especially when chiral symmetry is respected.
Review
Physics, Multidisciplinary
Karsten Held, Liang Si, Paul Worm, Oleg Janson, Ryotaro Arita, Zhicheng Zhong, Jan M. Tomczak, Motoharu Kitatani
Summary: In this study, the electronic structure of nickelate superconductors is reviewed, with and without considering the effects of electronic correlations. The results reveal that specific orbitals and an electron reservoir play key roles in the superconducting doping regime. Furthermore, the study finds that different physical phenomena can emerge under specific conditions, suggesting that different mechanisms may affect the occurrence of superconductivity.
FRONTIERS IN PHYSICS
(2022)
Article
Physics, Multidisciplinary
Sota Kitamura, Hideo Aoki
Summary: The authors demonstrate that circularly-polarised light can induce a topological superconducting state with broken time-reversal symmetry in a d-wave superconductor, revealing the importance of non-equilibrium engineering for realizing novel quantum phases.
COMMUNICATIONS PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Paul Worm, Liang Si, Motoharu Kitatani, Ryotaro Arita, Jan M. Tomczak, Karsten Held
Summary: Motivated by recent discoveries in nickelate compounds, this study investigates the effect of electronic correlations on their superconducting properties. For the pentalayer nickelate Nd6Ni5O12, correlations are found to push the material into the superconducting doping range, while for the bilayer nickelate Nd3Ni2O6, correlations result in a three-orbital regime. The findings suggest that substituting ions can restore the single-orbital physics with optimal doping.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Physics, Condensed Matter
Sharareh Sayyad, Motoharu Kitatani, Abolhassan Vaezi, Hideo Aoki
Summary: We investigate the effects of nematicity, superconductivity, and non-Fermi liquid behavior on partially flat-band (PFB) models on the triangular lattice. Our main finding is that nematicity, driven by many-body effects, enhances the superconducting transition temperature in a systematic manner on the T (c) dome. The breaking of the sixfold symmetry leads to a stronger pairing interaction and more compact pairs in real space, accompanied by a non-Fermi character of electrons in the PFBs with many-body interactions.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Materials Science, Multidisciplinary
Changming Yue, Hideo Aoki, Philipp Werner
Summary: This study demonstrates that doublon-holon fluctuations in systems with half-filled narrow bands can enhance superconductivity and increase the superconducting Tc. The coupling to the wide band allows the narrow band to remain superconducting and reach the largest order parameter.
Article
Materials Science, Multidisciplinary
Motoharu Kitatani, Ryotaro Arita, Thomas Schaefer, Karsten Held
Summary: We review recent studies on superconductivity using diagrammatic extensions of dynamical mean field theory, which consider both local correlation effects and spatial long-range fluctuations. The results reproduce and predict experimental phase diagrams of strongly correlated systems, and reveal that the dynamical screening effect of the pairing interaction vertex has significant consequences for the transition temperature.
JOURNAL OF PHYSICS-MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Paul Worm, Motoharu Kitatani, Jan M. Tomczak, Liang Si, Karsten Held
Summary: In this study, a bilayer structure of Ba2CuO3+y was revealed using density-functional theory and dynamical mean-field theory. It was found that interlayer self-doping leads to a quasi-one-dimensional band with strong nesting and antiferromagnetic fluctuations, possibly responsible for the superconductivity in Ba2CuO3+y.
Article
Physics, Multidisciplinary
Kazunari Ochi, Hiroyuki Tajima, Kei Iida, Hideo Aoki
Summary: This study theoretically demonstrates the existence of resonant pair scattering in a two-band system with significantly different masses, leading to novel pairing properties and enhancing superfluidity/superconductivity.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Materials Science, Multidisciplinary
P. A. Maksym, H. Aoki
Summary: Potential barriers in bilayer graphene and monolayer transition metal dichalcogenides can split an unpolarized incident current into reflected and transmitted currents with opposite valley polarization. By adjusting the potential, 100% polarization can be obtained, and a valley polarizer can be realized using a collimated beam of carriers to incident on a barrier within a certain range of angles.
Article
Materials Science, Multidisciplinary
Josef Kaufmann, Christian Eckhardt, Matthias Pickem, Motoharu Kitatani, Anna Kauch, Karsten Held
Summary: The self-consistent D Gamma A approach is successfully applied to multiorbital models and ab initio materials calculations, reducing nonlocal correlations and critical temperatures effectively.