Neutron experiments as a test of anisotropic pairing inYBa2Cu3<

Abstract

We show that the anomalous temperature T dependences at low frequencies co observed in neutron measurements of the structure factor S(q, co) are compatible with a d 2 2 pairing state. We further X demonstrate that convincing verification of this anisotropic pairing also requires the observation of a q dependence which, in low-T neutron data, di6'ers significantly from that above T, . In the absence of such evidence, establishing the existence of the d 2 2 state remains problematical. X J

Magnetic excitations and their anisotropy inYBa2Cu3O6+x: Slave-boson mean-field analysis of the bilayerYamase1, Metzner2 2006Phys. Rev. B8671130View full textAdd to dashboardCite

“…11(a)], which is a robust feature coming from the d-wave gap nodes. These DIC signals were already predicted about a decade ago, [27,113] As seen in Figs. 16(a) and (c), the upward dispersion in the high energy region is rather robust to temperature while in the low energy region temperature spoils the incommensurate structures in favor of a broad commensurate signal.…”

Detectingd-wave pairing and collective modes in fermionic condensates with Bragg scattering

“…This T = 0 result only contains the pairbreaking terms because the scattering terms vanish for T = 0, and both are necessary to recover the normal-state limit, which follows directly from the result [21]. The calculation of the inelastic neutron response, notably in cuprates [22,23], is very similar to this calculation; frequently, in cuprate calculations [24,25] the RPA analysis contains a magnetic structure J (q) = [cos(q x ) + cos(q y )], bilayer effects, or Coulomb interactions, which are absent here. …”

Exact correlation functions in the cuprate pseudogap phase: Combined effects of charge order and pairing

“…Figure (1) shows that there is little difference in the spin dynamics between the approach of YRZ [7] and that of a d-wave pseudogap, emphasized earlier in a different context [33] and helps to explain the literature claims of successful reconciliation with the data that surround both scenarios [26,27,31].…”

“…[Note we adopt the sign convention for the density correlation functions, P ρρ (Q) = P 00 (Q) for spin and charge.] For simple d-wave pairing models, a very reasonable comparison between theory and neutron data has been reported at high temperatures (where one sees a reflection of the fermiology [23,24]) and below T C (where one sees both commensurate (π, π) [25] and slightly incommensurate frequency dependent "hourglass" structure [26,27]). This approach to neutron scattering presents a (rather successful) rival scheme to stripe approaches; many different theories, built on different microscopics, have arrived at similar behavior [28][29][30][31].…”