Magnetic fluctuations in n-type high-$T_c$ superconductors reveal breakdown of fermiology

Abstract

By combining experimental measurements of the quasiparticle and dynamical magnetic properties of optimally electron-doped Pr${}_{0.88}$LaCe${}_{0.12}$CuO${}_4$ with theoretical calculations we demonstrate that the conventional fermiology approach cannot possibly account for the magnetic fluctuations in these materials. In particular, we perform tunneling experiments on the very same sample for which a dynamical magnetic resonance has been reported recently and use photoemission data by others on a similar sample to characterize the fermionic quasiparticle excitations in great detail. We subsequently use this information to calculate the magnetic response within the conventional fermiology framework as applied in a large body of work for the hole-doped superconductors to find a profound disagreement between the theoretical expectations and the measurements: this approach predicts a step-like feature rather than a sharp resonance peak, it underestimates the intensity of the resonance by an order of magnitude, it suggests an unreasonable temperature dependence of the resonance, and most severely, it predicts that most of the spectral weight resides in incommensurate wings which are a key feature of the hole-doped cuprates but have never been observed in the electron-doped counterparts. Our findings strongly suggest that the magnetic fluctuations reflect the quantum-mechanical competition between antiferromagnetic and superconducting orders.

10 pages, 9 figures, 1 table

References in corpus (5)

• Resonance in the electron-doped high-Tc superconductor Pr0.88LaCe0.12CuO(4-delta)
• Magnetic excitations in a bond-centered stripe phase: Spin waves far from the semi-classical limit
• Magnetic Excitations and their energy change available to Superconducting Condensation in Optimally Doped YBa${}_2$Cu${}_3$O${}_{6.95}$
• High Energy Spin Excitations in Electron-Doped Superconducting Pr${}_{0.88}$LaCe${}_{0.12}$CuO${}_{4-\delta }$ with $T_c=21$ K
• Nonmonotonic $d_{x^2-y^2}$ superconducting gap in electron-doped Pr${}_{0.89}$LaCe${}_{0.11}$CuO${}_4$: Evidence of coexisting antiferromagnetism and superconductivity?

Cited by in corpus (5)

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• Intermediate Coupling Model of the Cuprates
• Nature of the spin resonance mode in CeCoIn${}_5$
• Spin and bond-charge excitation spectra in correlated electron systems near antiferromagnetic phase