Quantum Critical Phase and Lifshitz Transition in an Extended Periodic Anderson Model

We study the quantum phase transition in $f$-electron systems as a quantum Lifshitz transition driven by selective Mott localization in a realistic extended Anderson lattice model. Using DMFT, we find that a quantum critical {\it phase} with anomalous $\omega/T$ scaling separates a heavy Landau-Fermi liquid from ordered phase(s). Fermi surface reconstruction occurs via the interplay between, and penetration of the Green function zeros to the poles, leading to violation of Luttinger's theorem in the selective-Mott phase . We show how this naturally leads to scale-invariant responses in transport. Our work is represents a specific (DMFT) realization of the hidden-FL and FL$^{*}$ theories, and holds promise for study of "strange" metal phases in quantum matter.Comment: 8 pages,5 figure

Theoretical study on spintronic and optical property prediction of doped magnetic Borophene

Two dimensional materials are attracting new research for optoelectronics and spintronics due to their unique physical properties. A wide range of emerging spintronic devices are achieved from parent and doped two dimensional materials. First-principles electronic structure calculations of a two-dimensional monolayer of borophene in its P6/mmm form is explored in this study. The electronic, magnetic, and optical properties of doped borophene are analyzed for doping with lithium, sodium, and magnesium. Density functional theory calculations advocate their good dynamical and thermal stability. Spin-polarized electronic properties of these materials are observed to be useful for predicting new spintronic materials. Additionally optical analysis exhibits the absorption peaks in monolayers along the in-plane direction. These properties of doped magnetic borophene suggest the material to be a suitable candidate for designing optoelectronic devices. The most competent spintronic material among three different doped borophenes is lithium doping that can imply a promising avenue for the fast-growing electronics industry

Intercalation in 2H-TaSe 2 for modulation of electronic properties and electrochemical energy storage

Two-dimensional transition metal dichalcogenides (TMDs) exhibit an extensive variety of novel electronic properties, such as charge density wave quantum spin Hall phenomena, superconductivity, and Dirac and Weyl semi-metallic properties. The diverse properties of TMDs suggest that structural transformation can be employed to switch between different electronic properties. Intercalation and zero valence doping of molecules and atoms into the van der Waals gap of TMDs have emerged as effective approaches to modify the charge order states of the material. This eventually leads to phase transition or the formation of different phases, thus expanding the electronic, thermoelectric and optical applications of these materials. In this study, electronic and electrochemical energy storage properties of such an intercalated TMD, namely, 2H-TaSe 2 via intercalation of lithium (Li), sodium (Na) and potassium (K) have been investigated. The intercalation of these ions into the dichalcogenide resulted in a modified band structure and novel structural effects, leading to the emergence of a 1 eV band gap. Possibility of electrochemical energy storage application is also explored in this study. Furthermore, the importance of multi orbital electron-electron correlations in intercalated TaSe 2 is also investigated via dynamical-mean-field theory with local density approximation.Comment: Accepted in Physica B, Condensed Matte