Harion Rozak | Searcharxiv

arXiv2022

Muon-Spin Motion at the Crossover Regime between Gaussian and Lorentzian Distribution of Magnetic Fields

The muon spin relaxation method (μSR) is a powerful microscopic tool to probe electronic states of materials observing local magnetic field distributions on the muon. It often happens that a distribution of local magnetic fields shows intermediate state between Gaussian and Lorentzian shapes. In order to generally describe intermediate field distributions, we dealt the convolution of two isotropic distributions in the three dimension and derived exact muon-spin relaxation functions which can be applied to all crossover regimes between the Gaussian and Lorentzian.

cond-mat.str-el↗

arXiv2022

Estimation of the on-site Coulomb potential 1 and covalent state in La2CuO4 by muon spin rotation 2 and density functional theory calculations

The on-site Coulomb potential, U, and the covalent state of electronic orbitals play key roles for the Cooper pair symmetry and exotic electromagnetic properties of high-Tc superconducting cuprates. In this paper, we demonstrate a way to determine the value of U and present the whole picture of the covalent state of Cu spins in the mother system of the La-based high-Tc superconducting cuprate, La2CuO4, by combining the muon spin rotation (μSR) and the density functional theory (DFT) calculation. We reveal local deformations of the CuO6 octahedron followed by changes in Cu-spin distributions caused by the injected muon. Adjusting the DFT and muSR results, U and the minimum charge-transfer energy between the upper Hubbard band and the O 2p band were optimized to be 4.87(4) and 1.24(1) eV, respectively.

cond-mat.str-el↗