Metallic spin-liquid-like behavior of LiV2 O4

LiV2O4 spinel is known to exhibit heavy-fermion-like behavior below a characteristic temperature TK≃20 K, while it preserves a paramagnetic state down to T∼10-2 K due to geometrical frustration. Here, it is shown that the dynamical spin susceptibility χ(q,ω) in LiV2O4 exhibits an anomalous duality which is modeled as a sum of itinerant (χF) and local (χL) components, and that the local spin dynamics inferred from χL(q,ω) is qualitatively different from that expected from time-averaged bulk properties. The anomaly coexists with the marginal Fermi-liquid behavior inferred from the -lnT dependence of the electronic specific heat over a wide temperature range below TK. We argue that such unusual properties of LiV2O4 can be attributed to the putative metallic spin-liquid state emerging near the quantum critical point between spin-glass and Fermi-liquid states.