相关论文: Contrasting Dynamic Spin Susceptibility Models and…
Conventional superconductors are robust diamagnets that expels magnetic fields through the Meissner effect. It would therefore be unexpected if a superconducting ground state would support spontaneous magnetics fields. Such broken…
Neutron scattering is used to probe antiferromagnetic spin fluctuations in the d-wave heavy fermion superconductor CeCoIn$_{5}$ (T$_{c}$=2.3 K). Superconductivity develops from a state with slow ($\hbar\Gamma$=0.3 $\pm$ 0.15 meV)…
The organizers of the Memorial Session for Herman Rietschel asked that I review some of the history of the interplay of superconductivity and spin fluctuations. Initially, Berk and Schrieffer showed how paramagnon spin fluctuations could…
In order to identify the most favorable situation for superconductivity in the repulsive single-band Hubbard model, we have studied instabilities for d-wave pairing mediated by antiferromagnetic spin fluctuations and p-pairing mediated by…
Magnetic susceptibility and muon spin rotation (\muSR) experiments have been carried out to study the effect of structural disorder on the non-Fermi-liquid (NFL) behavior of the heavy-fermion alloy Ce(Ru_{0.5}Rh_{0.5})_2Si_2. Analysis of…
There is compelling evidence from inelastic-neutron-scattering and tunneling experiments that the heavy-fermion superconductor UPd$_2$Al$_3$ can be understood as a dual system consisting of magnetic excitons, arising from…
Measurements of proton Nuclear Magnetic Resonance (1H NMR) spectra and relaxation and of Muon Spin Relaxation ($\mu^{+}$SR) have been performed as a function of temperature and external magnetic field on two isostructural lanthanide…
The issue of the spin gap in the magnetic susceptibility $\chi''(q,\omega)$ in high T_c superconductors is discussed within a scenario of a mixture of localized tightly bound electron pairs in singlet states (bi-polarons) and itinerant…
The quantum spin fluctuations of the S = 1/2 Cu ions are important in determining the physical properties of the high-transition temperature (high-Tc) copper oxide superconductors, but their possible role in the electron pairing for…
The superconducting equivalent of giant magnetoresistance, involves placing a thin-film superconductor between two ferromagnetic layers. A change of magnetization-alignment in such a superconducting spin-valve from parallel (P) to…
Superconductivity mediated by spin fluctuations in weak and nearly ferromagnetic metals is studied close to the zero-temperature magnetic transition. We solve analytically the Eliashberg equations for p-wave pairing and obtain the normal…
We study the normal and the superconducting properties in noncentrosymmetric heavy fermion superconductors CeRhSi$_3$ and CeIrSi$_3$. For the normal state, we show that experimentally observed linear temperature dependence of the…
Nuclear magnetic resonance (NMR) measurements on the $^{195}$Pt nucleus in an aligned powder of the moderately heavy-fermion material U2PtC2 are consistent with spin-triplet pairing in its superconducting state. Across the superconducting…
While the spin dynamics of La$_{0.7}$Ca$_{0.3}$MnO$_3$ in the ferromagnetic phase are known to be unconventional, previous measurements have yielded contradictory results regarding the damping of spin wave excitations. Neutron spectroscopy…
We measured the static uniform spin susceptibility of Ba(Fe$_{1-x}$Rh$_x$)$_2$As$_2$ iron-based superconductors, over a broad range of doping ($0.041\leq x\leq 0.094$) and magnetic fields. At small fields ($H \le$ 1 kOe) we observed, above…
A detailed inelastic neutron scattering study of the high temperature superconductor $\rm YBa_2Cu_3O_{6.85}$ provides evidence of new resonant magnetic features, in addition to the well known resonant mode at 41 meV: (i) a commensurate…
Complex magneto structural behaviour of rare rich intermetallic Tb$_3$Co is reported in this study. Below the 84K (T$_N$), it undergoes a first order magnetic transition 72K confirmed from specific heat and magnetization measurements.…
The conformal anomaly indicates the breaking of conformal symmetry (angle-preserving transformations) in the quantum theory by quantum fluctuations and is a close cousin of the gravitational anomaly. We show, for the first time, that the…
We analyse the momentum dependence of static non-uniform susceptibilities of layered local-moment systems below Curie (Neel) temperature within the 1/S-expansion, the renormalization-group approach, and first order of 1/N-expansion. We…
The presence of spin-orbit (SO) interaction in a noncentrosymmetric superconductor, La2C3 (T_c~11 K) is demonstrated by muon spin rotation (muSR) in its normal state, where muSR spectra exhibit field-induced weak depolarization due to van…