Cross relaxation and the bilayer coupling in YBCO

Abstract

There is strong experimental evidence for substantial antiferromagnetic coupling between the CuO${}_2$ planes of the bilayers in YBCO compounds. The acoustic mode of the spin excitation spectrum has been measured but the optic mode has not been observed. Theoretical estimates suggest values for the antiferromagnetic interplane coupling as large as 10 meV. It has been proposed that this coupling is responsible for the spin gap in the underdoped YBCO compounds. In the recently synthesized compounds Y${}_2$Ba${}_4$Cu${}_7$O${}_{15}$ with alternating single/double chain blocks, it is possible to distinguish between the CuO${}_2$ planes in a bilayer. We propose a nuclear magnetic cross relaxation experiment to directly measure the strength of the coupling between the two planes of a bilayer. The temperature dependence and magnitude of this cross relaxation rate is predicted.

2 pages, Postscript, to be published in Proceedings of M2S - HTSC, Grenoble

References in corpus (3)

• Toward a Unified Magnetic Phase Diagram of the Cuprate Superconductors
• Spin Gaps and Spin Dynamics in La_{2-x}Sr_xCuO_4 and YBa_2Cu_3O7_δ
• Order-Disorder Transition in a Two-Layer Quantum Antiferromagnet

Cited by in corpus (7)

• LDA energy bands, low-energy Hamiltonians, t', t'', t_{perp}(k), and J_{perp}
• On the Bilayer Coupling in the Yttrium-Barium Family of High Temperature Superconductors
• Effects of intrabilayer coupling on the magnetic properties of YBa${}_2$Cu${}_3$O${}_6$
• Spin Gaps in High Temperature Superconductors
• Strong-coupling Expansions at Finite Temperatures: Application to Quantum Disordered and Quantum Critical Phases
• Origin for the enhanced copper spin echo decay rate in the pseudogap regime of the multilayer high-T_c cuprates
• Interplane magnetic coupling effects in the multilattice compound Y_2Ba_4Cu_7O_{15}