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arXiv · 1607.05238

Suppression of Superfluid Density and the Pseudogap State in the Cuprates by Impurities

Unurbat Erdenemunkh·Brian Koopman·Ling Fu·Kamalesh Chatterjee·W. D. Wise·G. D. Gu·E. W. Hudson·Michael C. Boyer
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Abstract

We use scanning tunneling microscopy (STM) to study magnetic Fe impurities intentionally doped into the high-temperature superconductor Bi$_{2}$Sr$_{2}$Ca$_{2}$CuO$_{8+\delta}$. Our spectroscopic measurements reveal that Fe impurities introduce low-lying resonances in the density of states at \Omega$_{1}$ $\approx$ 4meV and \Omega$_{2}$ $\approx$ 15 meV allowing us to determine that, despite having a large magnetic moment, potential scattering of quasiparticles by Fe impurities dominates magnetic scattering. In addition, using high-resolution spatial characterizations of the local density of states near and away from Fe impurities, we detail the spatial extent of impurity affected regions as well as provide a local view of impurity-induced effects on the superconducting and pseudogap states. Our studies of Fe impurities, when combined with a reinterpretation of earlier STM work in the context of a two-gap scenario, allow us to present a unified view of the atomic-scale effects of elemental impurities on the pseudogap and superconducting states in hole-doped cuprates; this may help resolve a previously assumed dichotomy between the effects of magnetic and non-magnetic impurities in these materials.

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Unurbat Erdenemunkh, Brian Koopman, Ling Fu, Kamalesh Chatterjee, W. D. Wise, G. D. Gu, E. W. Hudson, Michael C. Boyer. 2016-07-18. Suppression of Superfluid Density and the Pseudogap State in the Cuprates by Impurities. https://doi.org/10.1103/physrevlett.117.257003

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