C-axis electronic Raman scattering in Bi_2Sr_2CaCu_2O_{8+\delta}

TL;DR

This study investigates the c-axis electronic Raman scattering in Bi_2Sr_2CaCu_2O_{8+eta} single crystals, revealing a high-energy continuum in the normal state and a distinct superconducting coherence peak at 50 meV, indicating different quasiparticle dynamics.

Contribution

It provides the first detailed analysis of c-axis polarized electronic Raman scattering in this cuprate superconductor, highlighting polarization-dependent quasiparticle excitation dynamics.

Findings

Resonant electronic continuum extends to 1.5 eV in normal state

Superconducting state shows a coherence peak at 50 meV

Peak energy differs from in-plane polarization measurements

Abstract

We report a c-axis-polarized electronic Raman scattering study of Bi_2Sr_2CaCu_2O_{8+\delta} single crystals. In the normal state, a resonant electronic continuum extends to 1.5 eV and gains significant intensity as the incoming photon energy increases. In the superconducting state, a coherence 2\Delta peak appears around 50 meV, with a suppression of the scattering intensity at frequencies below the peak position. The peak energy, which is higher than that seen with in-plane polarizations, signifies distinctly different dynamics of quasiparticle excitations created with out-of-plane polarization.