Novel Quantum Criticality in Two Dimensional Topological Phase transitions

Topological quantum phase transitions intrinsically intertwine self-similarity and topology of many-electron wave-functions, and divining them is one of the most significant ways to advance understanding in condensed matter physics. Our focus is to investigate an unconventional class of the transitions between insulators and Dirac semimetals whose description is beyond conventional pseudo relativistic Dirac Hamiltonian. At the transition without the long-range Coulomb interaction, the electronic energy dispersion along one direction behaves like a relativistic particle, linear in momentum, but along the other direction it behaves like a non-relativistic particle, quadratic in momentum. Various physical systems ranging from TiO${}_2$-VO${}_2$ heterostructure to organic material $\alpha$-(BEDT-TTF)${}_2$ I${}_3$ under pressure have been proposed to have such anisotropic dispersion relation. Here, we discover a novel quantum criticality at the phase transition by incorporating the 1/r long-range Coulomb interaction. Unique interplay between the Coulomb interaction and electronic critical modes enforces not only the anisotropic renormalization of the Coulomb interaction but also marginally modified electronic excitation. In connection with experiments, we investigate several striking effects in physical observables of our novel criticality.Comment: 12 pages + 31 pages, 5 figures, 2 tables, published versio

Topological Phase Transitions in Line-nodal Superconductors

Fathoming interplay between symmetry and topology of many-electron wave-functions has deepened understanding of quantum many body systems, especially after the discovery of topological insulators. Topology of electron wave-functions enforces and protects emergent gapless excitations, and symmetry is intrinsically tied to the topological protection in a certain class. Namely, unless the symmetry is broken, the topological nature is intact. We show novel interplay phenomena between symmetry and topology in topological phase transitions associated with line-nodal superconductors. The interplay may induce an exotic universality class in sharp contrast to that of the phenomenological Landau-Ginzburg theory. Hyper-scaling violation and emergent relativistic scaling are main characteristics, and the interplay even induces unusually large quantum critical region. We propose characteristic experimental signatures around the phase transitions in three spatial dimensions, for example, a linear phase boundary in a temperature-tuning parameter phase-diagram.Comment: 4 + 23 pages, 7 figures, 1 table; the first two authors contributed equally to this wor

Development of A New Coating System for The High Functional Mold in Thin-wall Casting

A new inorganic binder system has been developed to prepare the mold having a high strength for the thin-walled casting. To increase the fracture strength at high temperature, a large amount of inorganic binder should be converted into glass phase and the generated glass phase has to be homogeneously coated on the surface of starting particles. In this work, two types of process were employed to investigate the coating and glassification efficiencies of inorganic precursor. In the first process (process I), the green body consisting of starting powder and organic binder was dipped in the inorganic precursor solution. In the second process (process II), the starting powder was coated by inorganic precursor, and then the organic binder was used to form the green body. The mold sample prepared using process II showed the higher strength value than that using process I, owing to the inclement effect on the glassfication efficiency by the loss of inorganic precursor in process I. The prepared real mold was perfectly produced and the casted product showed a clean surface without defects such as dross, nonmetallic inclusions, and crack. Consequently, the new inorganic binder system could be applied for preparing the mold for the thin-wall casting having high mechanical properties

Parameter Calibration Method Based On GA Technique For Multi-Event

Accurate parameter estimation based catchment modeling systems requires considerable work to establish credibility. In this paper, a methodology for parameter estimation of hydrologic simulation model is proposed to simultaneously include several rainfall events using Shannon entropy. The proposed methodology uses Genetic Algorithm(GA) optimization techniques for the Storm Water Management Model (SWMM). Shannon entropy theory was applied to calculate weights according to each rainfall event in study area. A case study application was undertaken using the Milyang-dam basin, in Korea. Three events are applied to calculate Shannon entropy weights. Then, Nash-Sutcliffe Efficiency(NSE) & Root Mean Square Error(RMSE) are compared with those from single event. This study suggests that the proposed methodology is capable of providing effective parameter estimation method

Systematic multiomics analysis of alterations in c1qbp mrna expression and relevance for clinical outcomes in cancers

Acknowledgement: This study was supported by KU-Research Professor Program of Konkuk University.Peer reviewe

In-situ fabrication of cobalt-doped SrFe2As2 thin films by using pulsed laser deposition with excimer laser

The remarkably high superconducting transition temperature and upper critical field of iron(Fe)-based layered superconductors, despite ferromagnetic material base, open the prospect for superconducting electronics. However, success in superconducting electronics has been limited because of difficulties in fabricating high-quality thin films. We report the growth of high-quality c-axis-oriented cobalt(Co)-doped SrFe2As2 thin films with bulk superconductivity by using an in-situ pulsed laser deposition technique with a 248-nm-wavelength KrF excimer laser and an arsenic(As)-rich phase target. The temperature and field dependences of the magnetization showing strong diamagnetism and transport critical current density with superior Jc-H performance are reported. These results provide necessary information for practical applications of Fe-based superconductors.Comment: 8 pages, 3figures. to be published at Appl. Phys. Let