Spin dynamics in the pseudogap state of a high-temperature superconductor

Abstract

The pseudogap is one of the most pervasive phenomena of high temperature superconductors. It is attributed either to incoherent Cooper pairing setting in above the superconducting transition temperature Tc, or to a hidden order parameter competing with superconductivity. Here we use inelastic neutron scattering from underdoped YBa(2)Cu(3)O(6.6) to show that the dispersion relations of spin excitations in the superconducting and pseudogap states are qualitatively different. Specifically, the extensively studied "hour glass" shape of the magnetic dispersions in the superconducting state is no longer discernible in the pseudogap state and we observe an unusual "vertical" dispersion with pronounced in-plane anisotropy. The differences between superconducting and pseudogap states are thus more profound than generally believed, suggesting a competition between these two states. Whereas the high-energy excitations are common to both states and obey the symmetry of the copper oxide square lattice, the low-energy excitations in the pseudogap state may be indicative of collective fluctuations towards a state with broken orientational symmetry predicted in theoretical work.

6 pages, 8 figures, contains supplementary information. Some data from V. Hinkov et al., arXiv:cond-mat/0601048, is included

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Cited by in corpus (21)

• Electronic liquid crystal state in the high-temperature superconductor YBCO(6.45)
• Lattice symmetry breaking in cuprate superconductors: Stripes, nematics, and superconductivity
• Strength of the Spin-Fluctuation-Mediated Pairing Interaction in a High-Temperature Superconductor
• Renormalization group theory of nematic ordering in d-wave superconductors
• Magnetic-field-enhanced incommensurate magnetic order in the underdoped high-temperature superconductor YBa(2)Cu(3)O(6.45)
• Theory of the nodal nematic quantum phase transition in superconductors
• The emergence of coherent magnetic excitations in the pseudogap phase of La2-xSrxCuO4
• Magnetic Excitations of the Diagonal Incommensurate Phase in Lightly-Doped La2-xSrxCuO4
• Superconducting d-wave stripes in cuprates: Valence bond order coexisting with nodal quasiparticles
• Interplay between incommensurate phases in the cuprates
• Fermi surface and order parameter driven vortex lattice structure transitions in twin-free YBa2Cu3O7
• Sharp optical phonon softening close to optimal doping in La${}_{2-x}$Ba${}_x$CuO${}_{4+\delta }$
• Theory of reduced singlet pairing without the underlying state of charge stripes in the high-temperature superconductor YBa_2Cu_3O_6.45
• Quantum Spin Excitations through the metal-to-insulator crossover in $YB{a}_{2}C{u}_3{O}_{6+y}$
• Self-masking of spontaneous symmetry breaking in layer materials
• Effective action, magnetic excitations and quantum fluctuations in lightly doped single layer cuprates
• Inward dispersion of the spin excitation spectrum of stripe-ordered La2NiO4+d
• Spin-phonon coupling, q-dependence of spin excitations and high-T${}_C$ superconductivity from band models
• Modelling Magnetic Fluctuations in the Stripe Ordered State
• Spin-stiffness of anisotropic Heisenberg model on square lattice and possible mechanism for pinning of the electronic liquid crystal direction in YBCO
• Intimate relations between electronic nematic, d-density wave and d-wave superconducting states