Magnetic topological semimetals (TSMs) are quantum materials with broken time-reversal symmetry (TRS) and isolated nodal points or lines near the Fermi level. Their properties would typically reveal from bulk-edge correspondence principle as nontrivial surface states such arcs drumhead states, etc. Depending on degeneracies distribution of nodes in crystal momentum space, TSMs usually classified into Weyl (WSMs), Dirac (DSMs), nodal-line (NLSMs), triple-point (TPSMs), In this review article,...

We study Escherichia coli chemotaxis behavior in environments with spatially and temporally varying attractant sources by developing a unique microfluidic system. Our measurements reveal frequency-dependent behavior. At low frequency, the E. population oscillates synchrony attractant. In contrast, fast-changing environments, response becomes smaller out of phase waveform. These observations are inconsistent well-known Keller-Segel equation. A new continuum model is proposed to describe level...

We study the nonequilibrium dynamics of photoexcited electrons in narrow-gap Mott insulator VO$_2$. The initial stages relaxation are treated using a quantum Boltzmann equation methodology, which reveals rapid ($\sim$ femtosecond time scale) to pseudothermal state characterized by few parameters that vary slowly time. long-time limit is then studied Hartree-Fock possibility excitation new metastable $M_1$ metal phase qualitatively consistent with recent experiment. general physical picture...

We use density functional plus $U$ methods to study the effects of a tensile or compressive substrate strain on charge-ordered insulating phase LuNiO$_3$. The numerical results are analyzed in terms Landau energy function, with octahedral rotational distortions perovskite structure included as perturbation. Approximately 4% leads first-order transition from an large amplitude breathing mode NiO$_6$ octahedra metallic state which absent but Jahn-Teller two Ni-O bonds become long and other...

We study the growth of entanglement entropy in density matrix renormalization group calculations real-time quench dynamics Anderson impurity model. find that with appropriate choice basis, is logarithmic both interacting and noninteracting single-impurity models. The understood from a chain model as critical behavior separating regimes linear saturation entropy, corresponding respectively to an overlapping gapped energy spectra set bath states. choices basis (energy-ordered orbitals),...

We present a ${4}^{\ensuremath{'}}/{m}^{\ensuremath{'}}$-respecting crisscross AFM model in two dimensions (2D) and three (3D), both belonging to the ${Z}_{2}$ classification exhibiting interesting magnetic high-order topological insulating (HOTI) phases. The topologically nontrivial phase 2D is characterized by fractional charge localized around corners quantized quadrupole moment. Moreover, our also exhibits moment, which unique feature compared with previous studies. 3D system stacked...

We study the growth of entanglement entropy and bond dimension with time in density matrix renormalization group simulations periodically driven single-impurity Anderson model. The is found to be related ordering bath orbitals relation driving period $T$ convergence radius Floquet-Magnus expansion. Ordering by their Floquet quasienergy reduce exponential rate computation at intermediate periods, suggesting new ways optimize product state calculations systems.

We study the topological phase transitions induced by Coulomb engineering in three triangular-lattice Hubbard models $AB_2$, $AC_3$ and $B_2C_3$, each of which consists two types magnetic atoms with opposite moments. The energy bands are calculated using Schwinger boson method. find that a transition can be triggered second-order (three-site) virtual processes between atoms, strengths controlled on-site interaction $U$. This new class have been rarely studied may realized variety real materials.

Spin and charge are two interrelated properties of electrons. However, most previous works on topological matter study the electronic magnonic excitations separately. In this paper, by combining density functional theory calculations with Schwinger boson method, we determine band structures magnon spectrum simultaneously in ferromagnetic ground state narrow-band-gap CoCu3(OH)6Cl2, which is an ABC stacking Kagome lattice material fractional occupancy Cu sites. This provides ideal platform to...

Modern scientific research has become largely a cooperative activity in the Internet age. We build simulation model to understand population-level creativity based on heuristic ant colony algorithm. Each researcher two parameters characterizing goodness of his own judgments and trust literature. study how distributions contributor change with problem scale, stage problem, computing power available. also identify situations where path dependence hasty due pressure productivity can...

Recent extensive studies of Escherichia coli (E. coli) chemotaxis have achieved a deep understanding its microscopic control dynamics. As result, various quantitatively predictive models been developed to describe the chemotactic behavior E. motion. However, population-level partial differential equation (PDE) that rationally incorporates such dynamics is still insufficient. Apart from traditional Keller–Segel (K–S) equation, many existing are integro-PDEs. The difficulty comes mainly cell...

This PhD thesis conducts a focused study of strongly correlated materials with localized electron orbitals. We have studied two real (LuNiO$_3$ and VO$_2$) one model system, i.e., the Anderson impurity model. The is divided into parts. In first part, we use DFT+$U$ method, to calculate equilibrium phase transitions LuNiO$_3$ as an example rare-earth nickelates under substrate-induced strain, nonequilibrium VO$_2$ narrow-gap Mott insulators laser-pulse-induced photoexcitations. effect...

This PhD thesis conducts a focused study of strongly correlated materials with localized electron orbitals. We have studied two real (LuNiO$_3$ and VO$_2$) one model system, i.e., the Anderson impurity model. The is divided into parts. In first part, we use DFT+$U$ method, to calculate equilibrium phase transitions LuNiO$_3$ as an example rare-earth nickelates under substrate-induced strain, nonequilibrium VO$_2$ narrow-gap Mott insulators laser-pulse-induced photoexcitations. effect adding...