Quasi-One-Dimensional Spin Dynamics in LiV2O4: One-to-Three-Dimensional Crossover as a Possible Origin of Heavy Fermion State

概要

論文の詳細を見る
Spin fluctuation in LiV2O4 is revisited by examining the earlier result of muon spin rotation/relaxation measurement. Instead of the relationship for the localized electron limit, that between muon depolarization rate and spin fluctuation rate (\nu_{\text{D}}) for itinerant electron systems is used to reanalyze data, which reveals that \nu_{\text{D}} varies linearly with temperature (\nu_{\text{D}}\propto T) over a range 10^{8}--10^{12} s-1 for 0.02\leq T<10^{2} K. Such a linear T behavior as well as the magnitude of \nu_{\text{D}} is fully consistent with the behavior of magnetic relaxation rate previously observed by inelastic neutron scattering (INS), demonstrating that \muSR and INS have a common time window over a fluctuation spectrum. The linear T dependence of \nu_{\text{D}} is understood as a specific feature predicted by a Hubbard model for intersecting one-dimensional (1D) chains. This quasi-1D character, which is coexistent with enhanced uniform susceptibility at low temperatures, supports the scenario of 1D-to-3D crossover for the microscopic origin of heavy-fermion behavior in LiV2O4.
2012-01-15