Neutron scattering from a collective spin fluctuation mode in aCuO2bilayer

Two-dimensional incommensurate and three-dimensional commensurate magnetic order and fluctuations in La2−xBaxCuO

“…Inelastic neutron scattering studies are consistent with an "hour glass" dispersion, wherein low energy spin excitations disperse out of IC wavevectors and merge or nearly-merge at the C wavevector to form a resonant spin excitation [23][24][25][26][27][28][29][30] . At higher energies, the excitations disperse out from the C wavevector, before turning over near the Brillouin zone boundaries 23,31,32 .…”

Evidence for an incommensurate magnetic resonance inLa2−xSrxCuOTranquada1, Lee2, Yamada3 et al. 2004Phys. Rev. B858972View full textAdd to dashboardCite

“…35 The most common approach is to calculate the magnetic response of the charge carriers themselves in the particle-hole channel, which is then enhanced with the random phase approximation. 36,37,38,39,40,41,42 Whether the calculated fluctuations are commensurate or incommensurate depends on the shape of the Fermi surface. 39,41,43 Using a model dispersion that gives a Fermi surface consistent with the results of angle-resolved photoemission spectroscopy (ARPES) for YBa 2 Cu 3 O 6+x and Bi 2 Sr 2 CaCu 2 O 8+δ yields a commensurate resonance peak.…”

Spin anisotropy of the magnetic excitations in the normal and superconducting states of optimally doped YBa2Cu3O6.9Headings1, Hayden2, Kulda3 et al. 2011Phys. Rev. B312261View full textAdd to dashboardCite

“…The presence of a mirror plane between the two planes of the bilayer means that the magnetic excitations have distinct odd (o) or even (e) character. In this description, the magnetic response is of the form [26][27][28][29] χ (h,k,l,ω) = χ e (h,k,ω) cos 2 πd c l The reported even resonance occurs at higher energy than in the odd channel.…”