Determination of doped charge density in superconducting cuprates from NMR or stripes

Manfred Bucher

paper

Determination of doped charge density in superconducting cuprates from NMR or stripes

arXiv:2012.05052

Abstract

Independent investigations of nuclear quadrupole resonance (NQR) and of stripes in high- $T_{c}$ cuprates find a small deviation of doped-hole density $h$ from the doping level of $L a_{2 - x} S r_{x} C u O_{4}$ . The value observed with NQR, $x - h \approx 0.02$ , agrees closely with the density of itinerant holes, $p ~$ , responsible for suppression of 3D-AFM, as obtained from stripe incommensurability. The stripe model's assumption that doped holes in $L a_{2 - x} S r_{x} C u O_{4}$ reside at oxygen sites, and that doped electrons in $L n_{2 - x} C e_{x} C u O_{4}$ ( $L n = P r, N d$ ) reside at copper sites, is (to a large degree) confirmed with NQR. The NQR finding of doped-hole probabilities in oxygen and copper orbitals of $H g B a_{2} C u O_{4 + δ}$ and other oxygen-enriched high- $T_{c}$ cuprates, $P_{p} ≃ P_{d} ≃ 1/2$ , as well as of oxygen-doped $Y B a_{2} C u_{3} O_{6 + y}$ , $P_{p} ≃ 2 P_{d} ≃ 2/3$ , is interpreted with the stripe model in terms of excess oxygen atoms in the $C u O_{2}$ planes and $C u O$ chains.

19 pages, 4 tables, 4 figures