A5012473544- Advanced Condensed Matter Physics
- Physics of Superconductivity and Magnetism
- Topological Materials and Phenomena
- Iron-based superconductors research
- Quantum many-body systems
- Rare-earth and actinide compounds
- Magnetic and transport properties of perovskites and related materials
- Quantum and electron transport phenomena
- Magnetism in coordination complexes
- Rings, Modules, and Algebras
- Electric Motor Design and Analysis
- 2D Materials and Applications
- Superconducting Materials and Applications
- Inorganic Chemistry and Materials
- Cosmology and Gravitation Theories
- Quantum Electrodynamics and Casimir Effect
- Theoretical and Computational Physics
- Black Holes and Theoretical Physics
- Control and Stability of Dynamical Systems
University of Tennessee at Knoxville
2020-2024
Oak Ridge National Laboratory
2020-2023
Indian Institute of Science Education and Research, Bhopal
2013
We study ribbons of the dice two-dimensional lattice (that we call ``dice ladders'') known to have nontrivial topological properties, such as Chern numbers 2 [Wang and Ran, Phys. Rev. B 84, 241103(R) (2011)]. Our main results are two fold. (1) Analyzing tight-binding model in presence Rashba spin-orbit coupling an external magnetic field, observed that ladders qualitatively display properties similar their counterpart all way limit only legs short direction. This includes flat bands near...
Motivated by recent experimental progress in transition metal oxides with the ${\mathrm{K}}_{2}\mathrm{Ni}{\mathrm{F}}_{4}$ structure, we investigate magnetic and orbital ordering $\ensuremath{\alpha}\text{\ensuremath{-}}{\mathrm{Sr}}_{2}\mathrm{Cr}{\mathrm{O}}_{4}$. Using first-principles calculations, first derive a three-orbital Hubbard model, which reproduces ab initio band structure near Fermi level. The unique reverse splitting of ${t}_{2g}$ orbitals...
Abstract Lattice geometry continues providing exotic topological phases in condensed matter physics. Exciting recent examples are the higher-order phases, manifesting via localized lower-dimensional boundary states. Moreover, flat electronic bands with a non-trivial topology arise various lattices and can hold finite superfluid density, bounded by Chern number C . Here we consider attractive interaction dice lattice that hosts = ± 2 show induced superconducting state exhibits second-order...
The magnetic and electronic phase diagram of a model for the quasi-one-dimensional alkali-metal iron selenide compound ${\mathrm{Na}}_{2}{\mathrm{FeSe}}_{2}$ is presented. novelty this material that valence ${\mathrm{Fe}}^{2+}$, contrary to most other iron-chain compounds with ${\mathrm{Fe}}^{3+}$. Using first-principles techniques, we developed three-orbital tight-binding reproduces ab initio band structure near Fermi level. Including Hubbard Hund couplings studying via density-matrix...
We studied a multi-orbital Hubbard model at half-filling for two and three orbitals per site on two-site cluster via full exact diagonalization, in wide range the onsite repulsion $U$, from weak to strong coupling, multiple ratios of Hund coupling $J_H$ $U$. The hopping matrix elements among were also varied extensively. At intermediate large we mapped results into Heisenberg model. For site, mapping is $S=1$ where by symmetry both nearest-neighbor $(\mathbf{S}_{i}\cdot\mathbf{S}_{j})$...
The condensation of spin-orbit-induced excitons in ${t}_{2g}^{4}$ electronic systems is attracting considerable attention. At large Hubbard $U$, antiferromagnetism was proposed to emerge from the Bose-Einstein Condensation (BEC) triplons (${J}_{\text{eff}}=1$). Here, we show that even at intermediate $U$ regimes, spin-orbit exciton possible leading also staggered magnetic order. canonical electron-hole excitations (excitons) transform into local triplon and this BEC strong coupling regime...
We report the results of a Hartree-Fock study applied to interacting electrons moving in two different bipartite lattices: dice and Lieb lattices, at half-filling. Both lattices develop ferrimagnetic order phase diagram $U$-$\lambda$, where $U$ is Hubbard onsite repulsion $\lambda$ Rashba spin-orbit coupling strength. Our main result observation an unexpected multitude topological phases for both lattices. All these are ferrimagnetic, but they differ among themselves their set six Chern...
We investigate the effects of electronic correlations on Bernevig-Hughes-Zhang model using real-space density matrix renormalization group (DMRG) algorithm. introduce a method to probe topological phase transitions in systems with strong DMRG, substantiated by an unsupervised machine learning methodology that analyzes orbital structure edges. Including full multi-orbital Hubbard interaction term, we construct diagram as function gap parameter ($m$) and strength ($U$) via exact DMRG...
Motivated by recent experimental progress on iron-based ladder compounds, we study the doped two-orbital Hubbard model for two-leg ${\mathrm{BaFe}}_{2}{\mathrm{S}}_{3}$. The is constructed using ab initio hopping parameters and ground state properties are investigated density matrix renormalization group method. We show that $(\ensuremath{\pi},0)$ magnetic ordering at half filling, with ferromagnetic rungs antiferromagnetic legs, becomes incommensurate upon hole doping. Moreover, depending...
Spin-1/2 chains with alternating antiferromagnetic (AFM) and ferromagnetic (FM) couplings have attracted considerable interest due to the topological character of their spin excitations. Here, using density functional theory density-matrix renormalization-group (DMRG) methods, we systematically studied dimerized chain system ${\mathrm{Na}}_{2}{\mathrm{Cu}}_{2}{\mathrm{TeO}}_{6}$ a ${d}^{9}$ electronic configuration. Near Fermi level, in nonmagnetic phase dominant states are mainly...
We investigate the effects of electronic correlations on Bernevig-Hughes-Zhang model using real-space density matrix renormalization group (DMRG) algorithm. introduce a method to probe topological phase transitions in systems with strong DMRG, substantiated by an unsupervised machine learning methodology that analyzes orbital structure edges. Including full multi-orbital Hubbard interaction term, we construct diagram as function gap parameter ($m$) and strength ($U$) via exact DMRG...