Kramers-Krönig (K-K) analysis of harmonic generation optical data is usually greatly limited by the technical inability to measure data over a wide spectral range. Data inversion for real and imaginary part of χ(nω;ω, ..., ω) can be more efficiently performed if the knowledge of one of the two parts of the susceptibility in a finite spectral range is supplemented with a single measurement of th...

We have studied the nonlinear index of refraction of pink ruby between 565 nm and 610 nm using nondegenerate two wave mixing at 77 K and 294 K. Our new results support the model originally proposed by Venkatesan and McCall based on the large cross section of the transition from the Kramers doublets to the charge transfer band. In addition, we show that two-wave mixing can be used for accurate d...

Being Wannierizable is not the end of story for topological insulators. We introduce a family insulators that would be considered trivial in paradigm set by tenfold way, quantum chemistry, and method symmetry-based indicators. Despite having symmetric, exponentially-localized Wannier representation, each function cannot completely localized to single primitive unit cell bulk. Such multicellular...

We present an ab initio derivation method for effective low-energy Hamiltonians of material with strong spin-orbit interactions. The Hamiltonian is described in terms the Wannier function spinor form, and interactions are derived constrained random phase approximation (cRPA) method. Based on this formalism developed code, we derive a interaction Ca5Ir3O12. This system consists three edge-shared...

This paper examines the highand low-frequency asymptotic consequences of the Kramers-Kronig relations which hold for the real and imaginary parts of the Fourier transform of the response of any linear causal system. By knowing or assuming the highor low-frequency expansion of one of these functions, the corresponding asymptotic expansion of the other is easily determined, and furthermore the co...

2014 Normal and oblique incidence reflectances of GaTe have been measured in the 2.5 to 26 eV range using polarized synchrotron radiation. We have deduced 3 complex refractive indices, relative to 3 different crystallographic directions by means of a new method consistent with the Kramers-Kronig relations. We have verified that the electronic transitions in the 20 eV region, from the 3d Ga leve...