In Weyl semimetals, there is an intriguing possibility of realizing a pseudo-magnetic field in presence of small strain due to certain special cases of static deformations. This pseudo-magnetic field can be large enough to form quantized Landau levels and thus become observable in Weyl semimetals. In this paper we experimentally show the emergence of a pseudo-magnetic field (∼ 3 Tesla) by Scanning Tunneling Spectroscopy (STS) on the doped Weyl semimetal Re-MoTe2, where distnict Landau level oscillations in the tunneling conductance are clearly resolved. The crystal lattice is intrinsically strained where large area STM imaging of the surface reveals differently strained domains where atomic scale deformations exist forming topographic ripples with varying periodicity in the real space. The effect of pseudo-magnetic field is clearly resolved in areas under maximum strain.

Majority of the A2B3 type chalcogenide systems with strong spin-orbit coupling, like Bi2Se3, Bi2Te3 and Sb2Te3 etc., are topological insulators. One important exception is Sb2Se3, where a topological non-trivial phase was argued to be possible under ambient conditions, but such a phase could be detected to exist only under pressure. In this Letter, we show that like Bi2Se3, Sb2Se3, displays generation of highly spin-polarized current under mesoscopic superconducting point contacts as measured by point contact Andreev reflection spectroscopy. In addition, we observe a large negative and anisotropic magnetoresistance in Sb2Se3, when the field is rotated in the basal plane. However, unlike in Bi2Se3, in case of Sb2Se3 a prominent quasiparticle interference (QPI) pattern around the defects could be obtained in STM conductance imaging. Thus, our experiments indicate that Sb2Se3 is a regular band insulator under ambient conditions, but due to it's high spin-orbit coupling, non-trivial spin-texture exists on the surface and the system could be on the verge of a topological insulator phase.

The surface states of topological insulators (TI) are protected by time reversal symmetry and they display intrinsic spin helicity where the momentum of the charge carriers decides their spin states. As a consequence, a current injected through the surface states becomes spin polarized and this transport spin-polarization leads to a proportionate suppression of Andreev reflection in superconductor/TI junctions. Here we show that upon doping BiSe with Mn, the transport spin-polarization is seen to be monotonically suppressed. The parent compound BiSe is found to exhibit a transport spin-polarization of about 63% whereas crystals with 10% Mn doping show transport spin-polarization of about 48%. This suppression is accompanied by an increasing ferromagnetic order of the crystals with Mn doping. Scanning tunneling spectroscopy shows that the topological protection of the surface states reduces due to Mn doping. The net measured transport spin-polarization is due to a competition of this effect with the increased magnetization on Mn doping. The present results provide important insights for the choice of magnetic topological insulators for spintronic applications.

A simple, sensitive, cost-effective and reproducible UV-spectrophotometric method has been developed and validated for the estimation of disodium edetate in topical gel formulations. Solution of disodium edetate reacts with ferric chloride to form complex in 0.1 N HCl giving λmax at 270 nm. Beer's law was obeyed in the concentration range of 5–50 μg/mL (r2= 0.9997). The limit of detection and limit of quantitation were found to be 1.190 and 3.608 μg/mL, respectively. The results show that the procedure is accurate, precise, and reproducible (relative standard deviation < 1%), while being simple and less time consuming. The study concluded that the UV-spectrophotometric method could be used for the quantification of disodium edetate in pure form as well as in pharmaceutical formulations.

The physical systems with ferromagnetism and ‘bad’ metallicity hosting unusual transport properties are playgrounds of novel quantum phenomena. Recently EuTi1−xNbxO3 emerged as a ferromagnetic system where non-trivial temperature dependent transport properties are observed due to coexistence and competition of various magnetic and non-magnetic scattering processes. In the ferromagnetic state, the resistivity shows a T2 temperature dependence possibly due to electron–magnon scattering and above the Curie temperature , the dependence changes to T3/2 behaviour indicating a correlation between transport and magnetic properties. In this paper, we show that the transport spin-polarization () in EuTi1−xNbxO3, a low Curie temperature ferromagnet, is as high (∼40%) as that in some of the metallic ferromagnets with high Curie temperatures. In addition, owing to the low Curie temperature of EuTi1−xNbxO3, the temperature (T) dependence of could be measured systematically up to which revealed a proportionate relationship with magnetization versus T. This indicates that such proportionality is far more universally valid than the ferromagnets with ideal parabolic bands. Furthermore, our band structure calculations not only helped to understand the origin of such high spin polarization in EuTi1−xNbxO3 but also provided a route to estimate the Hubbard U parameter in complex metallic ferromagnets in general using experimental inputs.