⁷⁷Se and⁶³Cu NMR studies of the electronic correlations in Cu_xTiSe₂(x= 0.05, 0.07)

Abstract

Abstract. We report 77 Se and 63 Cu nuclear magnetic resonance (NMR) investigation on the charge-density-wave (CDW) superconductor Cu x TiSe 2 (x = 0.05 and 0.07). At high magnetic fields where superconductivity is suppressed, the temperature dependence of 77 Se and 63 Cu spin-lattice relaxation rates 1/T 1 follow a linear relation. The slope of 77 1/T 1 vs T increases with the Cu doping. This can be described by a modified Korringa relation which suggests the significance of electronic correlations and the Se 4p-and Ti 3d -band contribution to the density of states at the Fermi level in the studied compounds.

Coexisting superconductivity and charge-density wave in hydrogen-doped titanium diselenide via ionic liquid gating-induced protonation

“…2c shows that, for T 170 K, T −1 1 exhibits a linear dependence on T consistent with the so-called Korringa behaviour proper of relaxation processes mediated by itinerant electrons in a metallic matrix [45]. This is in agreement with our ρ(T ) measurements and with the results of 77 Se-NMR measurements of 77 Se-enriched TiSe 2 and of 63 Cu-and 77 Se-NMR measurements of Cu-intercalated TiSe 2 [46,47]. Higher temperatures T 170 K mark a clear departure from the Korringa-like trend.…”