Theory of the in-plane anisotropy of magnetic excitations in YBa_{2}Cu_{3}O_{6+y}

Hiroyuki Yamase; Walter Metzner

doi:10.1016/j.physc.2007.03.429

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Theory of the in-plane anisotropy of magnetic excitations in YBa_{2}Cu_{3}O_{6+y}

Hiroyuki Yamase·Walter Metzner

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Abstract

A pronounced xy-anisotropy was observed in recent neutron scattering experiments for magnetic excitations in untwinned YBa_{2}Cu_{3}O_{6+y} (YBCO). The small anisotropy of the bare band structure due to the orthorhombic crystal symmetry seems to be enhanced by correlation effects. A natural possibility is that the system is close to a Pomeranchuk instability associated with a d-wave Fermi surface deformation (dFSD). We investigate this possibility in the bilayer t-J model within a self-consistent slave-boson mean-field theory. We show that the dFSD correlations drive a pronounced xy-anisotropy of magnetic excitations at low doping and at relatively high temperatures, providing a scenario for the observed xy-anisotropy in optimally doped as well as underdoped YBCO, including the pseudogap phase.

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Hiroyuki Yamase, Walter Metzner. 2007-01-25. Theory of the in-plane anisotropy of magnetic excitations in YBa_{2}Cu_{3}O_{6+y}. https://doi.org/10.1016/j.physc.2007.03.429

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