Eur. Phys. J. Special Topics 188, 49-59 (2010)
https://doi.org/10.1140/epjst/e2010-01296-9

Regular Article

Tendencies toward nematic order in YBa₂Cu₃O_6+δ: Uniform distortion vs. incipient charge stripes

Institut für Theoretische Physik, Universität zu Köln, Zülpicher Straße 77, 50937 Köln, Germany

Received: 14 July 2010
Revised: 12 August 2010
Published online: 11 October 2010

Abstract

Recent neutron scattering and transport data obtained on underdoped YBa₂Cu₃O_6+δ, with strong signatures of rotation symmetry breaking at low temperatures, point toward electron-nematic order in the charge sector. Such order may originate from a uniform distortion with d-wave symmetry or as a precursor of a uni-directional stripe phase. Here, we discuss whether the neutron scattering data can be linked to incipient charge stripes. We employ and extend a phenomenological model for collective spin and charge fluctuations and analyze the resulting spin excitation spectrum under the influence of lattice anisotropies. Our results show that the experimentally observed temperature-dependent magnetic incommensurability is compatible with a scenario of incipient stripes, the temperature dependence being due to the temperature variation of both strength and correlation length of the charge stripes. Finally, we propose further experiments to distinguish the possible theoretical scenarios.