In nodal-line semimetals, the gaps close along loops in k space, which are not at high-symmetry points. Typical mechanisms for the emergence of nodal lines involve mirror symmetry and the π Berry phase. Here we show via ab initio calculations that fcc calcium (Ca), strontium (Sr) and ytterbium (Yb) have topological nodal lines with the π Berry phase near the Fermi level, when spin-orbit interac...

We theoretically study the phase of the reflection amplitude of an electron (massive Dirac fermion) at a lateral potential step in Bernal-stacked bilayer graphene. The phase shows an anomalous jump of pi, as the electron incidence angle (relative to the normal direction to the step) varies to pass +/-pi/4. The jump is attributed to the Berry phase associated with the pseudospin-1/2 of the elect...

BACKGROUND This work describes a proteomics profiling method, optimized and applied to berry cell suspensions to evaluate organ-specific cultures as a platform to study grape berry ripening. Variations in berry ripening within a cluster(s) on a vine and in a vineyard are a major impediment towards complete understanding of the functional processes that control ripening, specifically when a char...

The anomalous Hall effect (AHE) arises from the interplay of spin-orbit interactions and ferromagnetic order and is a potentially useful probe of electron spin polarization, especially in nanoscale systems where direct measurement is not feasible. While AHE is rather well-understood in metallic ferromagnets, much less is known about the relevance of different physical mechanisms governing AHE i...

A new manifestation of the Berry-Phase is presented in the theory of fast rotating superfluid nuclei: Diabolic Pair Transfer, i.e. oscillations of the pair transfer matrix elements as a function of the angular velocity, is shown to be the direct consequence the Berry-Phase, giving a non-trivial contribution a t the diabolical points of cranked Hartree-Fock-Bogoliubov (HFB) spectra. Considering ...

OF THE DISSERTATION Various Geometric Aspects of Condensed Matter Physics by Zhenyu Zhou Doctor of Philosophy in Physics Washington University in St. Louis, 2013 Professor Alexander Seidel, Chairperson Geometric aspect of condensed matter has arouse a lot of interests in recent years. The idea of Berry phase is highly appreciated in various systems. We explored the geometric features of two spe...

The recent breakthrough in the discovery of Weyl fermions in monopnictide semimetals provides opportunities to explore the exotic properties of relativistic fermions in condensed matter. The chiral anomaly-induced negative magnetoresistance and π Berry phase are two fundamental transport properties associated with the topological characteristics of Weyl semimetals. Since monopnictide semimetals...

In this paper energy bands and Berry curvature of graphene was studied. Desired Hamiltonian regarding the next-nearest neighbors obtained by tight binding model. By using the second quantization approach, the transformation matrix is calculated and the Hamiltonian of system is diagonalized. With this Hamiltonian, the band structure and wave function can be calculated. By using calculated wave f...