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arXiv · 2105.06518

Scattering Interference Signature of a Pair Density Wave State in the Cuprate Pseudogap Phase

Shuqiu Wang·Peayush Choubey·Yi Xue Chong·Weijiong Chen·Wangping Ren·H. Eisaki·Shin-ichi Uchida·Peter J. Hirschfeld·J. C. Séamus Davis
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Abstract

An unidentified quantum fluid designated as the pseudogap (PG) phase is produced by electron-density depletion in the CuO$_2$ antiferromagnetic insulator. Current theories suggest that the PG phase may be a pair density wave (PDW) state characterized by a spatially modulating density of electron pairs. Such a state should exhibit a periodically modulating energy gap $Δ_P(\pmb r)$ in real-space, and a characteristic quasiparticle scattering interference (QPI) signature $Λ_P(\pmb q)$ in wavevector space. By studying strongly underdoped Bi$_2$Sr$_2$CaDyCu$_2$O$_8$ at hole-density ~0.08 in the superconductive phase, we detect the $8a_0$-periodic $Δ_P(\pmb r)$ modulations signifying a PDW coexisting with superconductivity. Then, by visualizing the temperature dependence of this electronic structure from the superconducting into the pseudogap phase, we find evolution of the scattering interference signature $Λ(\pmb q)$ that is predicted specifically for the temperature dependence of an $8a_0$-periodic PDW. These observations are consistent with theory for the transition from a PDW state coexisting with d-wave superconductivity to a pure PDW state in the Bi$_2$Sr$_2$CaDyCu$_2$O$_8$ pseudogap phase.

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Shuqiu Wang, Peayush Choubey, Yi Xue Chong, Weijiong Chen, Wangping Ren, H. Eisaki, Shin-ichi Uchida, Peter J. Hirschfeld, J. C. Séamus Davis. 2021-10-26. Scattering Interference Signature of a Pair Density Wave State in the Cuprate Pseudogap Phase. https://doi.org/10.1038/s41467-021-26028-x

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