Curie-like paramagnetism due to incomplete Zhang-Rice singlet formation in La2-xSrxCuO4

Abstract

In an effort to elucidate the origin of the Curie-like paramagnetism that is generic for heavily-overdoped cuprates, we have performed high transverse-field muon spin rotation (TF-muSR) measurements of La2-xSrxCuO4 single crystals over the Sr content range 0.145 < x < 0.33. We show that the x-dependence of the previously observed field-induced broadening of the internal magnetic field distribution above the superconducting transition temperature Tc reflects the presence of two distinct contributions. One of these becomes less pronounced with increasing x and is attributed to diminishing antiferromagnetic correlations. The other grows with increasing x, but decreases above x ~ 0.30, and is associated with the Curie-like term in the bulk magnetic susceptibility. In contrast to the Curie-like term, however, this second contribution to the TF-muSR line width extends back into the underdoped regime. Our findings imply a coexistence of antiferromagnetically correlated and paramagnetic moments, with the latter becoming dominant beyond x ~ 0.185. This suggests that the doped holes do not neutralize all Cu spins via the formation of Zhang-Rice singlets. Moreover, the paramagnetic component of the TF-muSR line width is explained by holes progressively entering the Cu 3d_{x^2-y^2} orbital with doping.

8 pages, 7 figures

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• The Persistence of High-Frequency Spin Fluctuations in Overdoped La${}_{2-x}$Sr${}_x$CuO${}_4$ ($x$=0.22)
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Cited by in corpus (8)

• Strongly-overdoped La${}_{2-x}$Sr${}_x$CuO${}_4$: Evidence for Josephson-coupled grains of strongly-correlated superconductor
• Broken relationship between superconducting pairing interaction and electronic dispersion kinks in LSCO
• Universal inhomogeneous magnetic-field response in the normal state of cuprate high-Tc superconductors
• From non-metal to strange metal at the stripe-percolation transition in La${}_{2-x}$Sr${}_x$CuO${}_4$
• Investigation of potential fluctuating intra-unit cell magnetic order in cuprates by muon spin relaxation
• Low-energy spin dynamics and critical hole concentrations in La${}_{2-x}$Sr${}_x$CuO${}_4$ ($0.07\le x\le 0.2$) revealed by ${}^{139}$La and ${}^{63}$Cu nuclear magnetic resonance
• First principle prediction of structural distortions in the cuprates and their impact on the electronic structure
• Charge order, superconducting correlations, and $\mu$SR