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Mass-renormalized electronic excitations at ($π$, 0) in the superconducting state of $Bi_{2}Sr_{2}CaCu_{2}O_{8+δ}$

A. D. Gromko·A. V. Fedorov·Y. -D. Chuang·J. D. Koralek·Y. Aiura·Y. Yamaguchi·K. Oka·Yoichi Ando·D. S. Dessau
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Abstract

Using high-resolution angle-resolved photoemission spectroscopy on $Bi_{2}Sr_{2}CaCu_{2}O_{8+δ}$, we have made the first observation of a mass renormalization or "kink" in the E vs. $\vec k$ dispersion relation localized near $(π, 0)$. Compared to the kink observed along the nodal direction, this new effect is clearly stronger, appears at a lower energy near 40 meV, and is only present in the superconducting state. The kink energy scale defines a cutoff below which well-defined quasiparticle excitations occur. This effect is likely due to coupling to a bosonic excitation, with the most plausible candidate being the magnetic resonance mode observed in inelastic neutron scattering.

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A. D. Gromko, A. V. Fedorov, Y. -D. Chuang, J. D. Koralek, Y. Aiura, Y. Yamaguchi, K. Oka, Yoichi Ando, D. S. Dessau. 2002-02-21. Mass-renormalized electronic excitations at ($π$, 0) in the superconducting state of $Bi_{2}Sr_{2}CaCu_{2}O_{8+δ}$. https://doi.org/10.1103/physrevb.68.174520

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