Abstract.A many-body theory of paramagnetic Kondo insulators is described, focusing specifically on single-particle dynamics, scattering rates, d.c. transport and optical conductivities. This is achieved by development of a non-perturbative local moment approach to the symmetric periodic Anderson model within the framework of dynamical mean-field theory.Our natural focus is the strong coupling, Kondo lattice regime; in particular the resultant 'universal' scaling behaviour in terms of the single, exponentially small low-energy scale characteristic of the problem. Dynamics/transport on all relevant (ω, T ) scales are considered, from the gapped/activated behaviour characteristic of the low-temperature insulator through to explicit connection to single-impurity physics at high ω and/or T ; and for optical conductivities emphasis is given to the nature of the optical gap, the temperature scale responsible for its destruction, and the consequent clear distinction between indirect and direct gap scales. Using scaling, explicit comparison is also made to experimental results for d.c. transport and optical conductivites of Ce 3 Bi 4 P t 3 , SmB 6 and Y bB 12 . Good agreement is found, even quantitatively; and a mutually consistent picture of transport and optics results.PACS numbers: 71.27.+a Strongly correlated electron systems; heavy fermions -75.20.Hr Local moment in compounds and alloys; Kondo effect, valence fluctuations, heavy fermions

We explore the Matsubara quasiparticle fraction and the pseudogap of the two-dimensional Hubbard model with the dynamical cluster quantum Monte Carlo method. The character of the quasiparticle fraction changes from non-Fermi-liquid, to marginal Fermi liquid, to Fermi liquid as a function of doping, indicating the presence of a quantum critical point separating non-Fermi-liquid from Fermi-liquid character. Marginal Fermi-liquid character is found at low temperatures at a very narrow range of doping where the single-particle density of states is also symmetric. At higher doping the character of the quasiparticle fraction is seen to cross over from Fermi liquid to marginal Fermi liquid as the temperature increases.

The periodic Anderson model (PAM) captures the essential physics of heavy fermion materials. Yet even for the paramagnetic metallic phase, a practicable many-body theory that can simultaneously handle all energy scales while respecting the dictates of Fermi liquid theory at low energies, and all interaction strengths from the strongly correlated Kondo lattice through to weak coupling, has remained quite elusive. Aspects of this problem are considered in the present paper where a non-perturbative local moment approach (LMA) to single-particle dynamics of the asymmetric PAM is developed within the general framework of dynamical mean-field theory. All interaction strengths and energy scales are encompassed, although our natural focus is the Kondo lattice regime of essentially localized f -spins but general conduction band filling, characterised by an exponentially small lattice coherence scale ωL. Particular emphasis is given to the resultant universal scaling behaviour of dynamics in the Kondo lattice regime as an entire function of ω ′ = ω/ωL, including its dependence on conduction band filling, f -level asymmetry and lattice type. A rich description arises, encompassing both coherent Fermi liquid behaviour at low-ω ′ and the crossover to effective single-impurity scaling physics at higher energies -but still in the ω/ωL-scaling regime, and as such incompatible with the presence of two-scale 'exhaustion' physics, which is likewise discussed.PACS. 71.27.+a Strongly correlated electron systems; heavy fermions -75.20.Hr Local moment in compounds and alloys; Kondo effect, valence fluctuations, heavy fermions

This corrects the article DOI: 10.1103/PhysRevLett.116.036401.

Conducting nanowire networks find diverse applications in solar cells, touch-screens, transparent heaters, sensors, and various related transparent conducting electrode (TCE) devices. The performances of these devices depend on effective resistance, transmittance, and local current distribution in these networks. Although, there have been rigorous studies addressing resistance and transmittance in TCE, not much attention is paid on studying the distribution of current. Present work addresses this compelling issue of understanding current distribution in TCE networks using analytical as well as Monte-Carlo approaches. We quantified the current carrying backbone region against isolated and dangling regions as a function of wire density (ranging from percolation threshold to many multiples of threshold) and compared the wired connectivity with those obtained from template-based methods. Further, the current distribution in the obtained backbone is studied using Kirchhoff's law, which reveals that a significant fraction of the backbone (which is believed to be an active current component) may not be active for end-to-end current transport due to the formation of intervening circular loops. The study shows that conducting wire based networks possess hot spots (extremely high current carrying regions) which can be potential sources of failure. The fraction of these hot spots is found to decrease with increase in wire density, while they are completely absent in template based networks. Thus, the present work discusses unexplored issues related to current distribution in conducting networks, which are necessary to choose the optimum network for best TCE applications.