Unconventional High-Energy-State Contribution to the Cooper Pairing in the Underdoped Copper-Oxide Superconductor HgBa 2 Ca 2 Cu 3 O 8 + δ
Abstract
We study the temperature-dependent electronic B1g Raman response of a slightly under-doped
single crystal HgBa2Ca2Cu3O8+δ with a superconducting critical temperature Tc =122 K. Our main
finding is that the superconducting pair-breaking peak is associated with a dip on its higher-energy
side, disappearing together at Tc . This result hints at an unconventional pairing mechanism, whereas
spectral weight lost in the dip is transferred to the pair-breaking peak at lower energies. This
conclusion is supported by cellular dynamical mean-field theory on the Hubbard model, which is
able to reproduce all the main features of the B1g Raman response and explain the peak-dip behavior
in terms of a nontrivial relationship between the superconducting and the pseudo gaps.
Domains
Physics [physics]
Origin : Files produced by the author(s)
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