相关论文: Intrinsic Spin Susceptibility and Pseudogap-like B…
We pursue the consequences of a theory in which the resonance peak observed in inelastic neutron scattering (INS) experiments on underdoped and optimally doped YBa$_2$Cu$_3$O$_{6+x}$ compounds arises from a spin-wave excitation. We find…
Local magnetic properties around a nonmagnetic impurity are investigated in high-Tc cuprate superconductors. We consider a model two-dimensional d-wave superconductor with strong antiferromagnetic (AF) spin fluctuations and calculate the…
The discovery of unconventional superconductivity around 80 K in perovskite nickelates under high pressure has furnished a new platform to explore high-temperature unconventional superconductivity in addition to cuprates. Understanding the…
The electronic properties of the high-temperature superconducting cuprates are encoded in complex sets of NMR data, but without microscopic theory, reliable NMR phenomenologies are in demand. Early analyses of NMR could only focus on very…
Spinel-structured compounds serve as prototypical examples of highly frustrated systems, and are promising candidates for realizing the long-sought quantum spin liquid (QSL) state. However, structural disorder is inevitable in many real QSL…
Layered perovskite iridates realize a rare class of Mott insulators that are predicted to be strongly spin-orbit coupled analogues of the parent state of cuprate high-temperature superconductors. Recent discoveries of pseudogap, magnetic…
The interplay between superconducting fluctuations and inhomogeneities presents a renewed interest due to recent works supporting an anomalous [beyond the conventional Gaussian-Ginzburg-Landau (GGL) scenario] diamagnetism above Tc in…
The recent observations of superconductivity at temperatures up to 55K in compounds containing layers of iron arsenide have revealed a new class of high temperature superconductors that show striking similarities to the more familiar…
We present neutron scattering measurements on single crystals of lightly doped $La_{2-x}Ba_{x}CuO_{4}$, with $0 \leq x \leq? 0.035$. These reveal the evolution of the magnetism in this prototypical doped Mott insulator from a three…
The superconducting state in the quasi-two-dimensional and strongly correlated Sr$_2$RuO$_4$ is uniquely held up as a solid state analog to superfluid $^3$He-$A$, with an odd-parity order parameter that also breaks time reversal symmetry,…
The $T^{\prime}$ infinite layered nickelates have recently garnered significant attention owing to the discovery of superconductivity in hole-doped RNiO$_2$ (R $=$ La, Pr, or Nd), which is the $n = \infty$ member of the series…
We report on 139La and 63Ccu NMR/NQR measurements in the high-Tc superconductor La1.90Sr0.10CuO4 with Tc=26.5 K. Spin fluctuations probed by 139La spin-lattice relaxation (T1), continuously slow down on cooling through Tc. We argue that…
The superconducting gap symmetry is investigated by $^{125}$Te NMR measurements on Sc$_6M$Te$_2$ ($M$ = Fe, Co) without spatial inversion symmetry. The spin susceptibility obtained from the Knight shift $K$ is suppressed below the…
After several decades of studies of high-temperature superconductivity, there is no compelling theory for the mechanism yet; however, the spin fluctuations have been widely believed to play a crucial role in forming the superconducting…
We present a theory of magnetic (S=1) Ni and nonmagnetic Zn impurities in underdoped cuprates. Both types of impurities are shown to induce S=1/2 moments on Cu sites in the proximity of the impurity, a process which is intimately related to…
Quasiparticle tunneling spectra of the electron-doped (n-type) infinite-layer cuprate Sr_{0.9}La_{0.1}CuO_2 reveal characteristics that counter a number of common phenomena in the hole-doped (p-type) cuprates. The optimally doped…
The intrinsic electronic properties of La$_3$Ni$_2$O$_{7}$ have been selectively investigated by nuclear quadrupole resonance (NQR) at the La(2) site outside the NiO$_2$ bilayers. The La(2)$_{\rm a}$ site of the ideal La$_3$Ni$_2$O$_{7}$ is…
This paper describes the first 63-Cu NMR study of an electron-doped infinitely-layered high Tc superconductor Sr$_0.9$La$_0.1$CuO$_2$ (Tc=42K). The spin dynamics in the normal state above Tc exhibits qualitatively the same behavior as some…
Building upon the recent progress on the intriguing underlying physics for the newly discovered infinite-layer nickelates, in this article we review an examination of valence charge and spin excitations via multi-orbital Hubbard models as…
^139La nuclear magnetic resonance studies reveal markedly different magnetic properties of the two sites created by the charged domain wall formation in La_(5/3)Sr_(1/3)NiO_4. NMR is slow compared to neutron scattering; we observe a 30 K…