Strange metal in paramagnetic heavy-fermion Kondo lattice: Dynamical large-N fermionic multi-channel approach

The mechanism of strange metal (SM) with unconventional charge transport near magnetic phase transitions has become an outstanding open problem in correlated electron systems. Recently, an exotic quantum critical SM phase was observed in paramagnetic frustrated heavy-fermion materials near Kondo breakdown. We establish a controlled theoretical framework to this issue via a dynamical large-N fermionic multichannel approach to the two-dimensional Kondo-Heisenberg lattice model, where KB transition separates a heavy-Fermi liquid from fermionic spin-liquid state. With Kondo fluctuations being fully considered, we find a distinct SM behavior with quasi-linear-in-temperature scattering rate associated with KB. When particle-hole symmetry is present, signatures of a critical spin-liquid SM phase as $T \rightarrow 0$ are revealed with $\omega/T$ scaling extended to a wide range. We attribute these features to the interplay of critical bosonic charge (Kondo) fluctuations and gapless fermionic spinons. The implications of our results for the experiments are discussed.Comment: 6 pages, 4 figure

Franchise Fee, Tax/Subsidy Policies and Economic Growth

In this paper, we take a new look at the effects of the subsidy policy and the government’s R&D activities in an R&D-based growth model. The government not only subsidizes the R&D cost of the firms but also engages in R&D activities and, in addition, levies a specific tax on the firms producing the final and the intermediate goods, respectively, in order to finance the expenditure. We find that in the economy there exist two balanced equilibrium growth paths. In an economy with a high growth path, the government’s subsidy policy and its R&D activities will crowd out the private R&D activities, and hence the fiscal policies are of no help to the economic growth. In other words, the intermediate goods firms play an important role in driving the economic growth. By contrast, in an economy with a low growth path, the government that directly engages in R&D activities plays an important role in economic growth. The fiscal policies of the government have a positive effect on the economic growth.Government’s R&D activities, Specific tax, Subsidy policy, Endogenous growth, R&D