Strontium intercalation between van der Waals bonded layers of topological insulator Bi 2 Se 3 is found to induce superconductivity with a maximum T c of 2.9 K. Transport measurement on single crystal of optimally doped sample Sr 0.1 Bi 2 Se 3 shows weak anisotropy ( 1.5) and upper critical field H c2 (0) Superconductors derived from topological insulating phases of quantum matter are amongst the most profound developments of recent past.

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We report synthesis of non-centrosymmetric BiPd single crystal by self flux method. The BiPd single crystal is crystallized in monoclinic structure with the P2 1 space group. Detailed SEM (Scanning Electron Microscopy) results show that the crystals are formed in slab like morphology with homogenous distribution of Bi and Pd. The magnetic susceptibility measurement confirmed that the BiPd compound is superconducting below 4K. Further, BiPd exhibits weak ferromagnetism near the superconducting transition temperature in isothermal magnetization (MH) measurements. The temperature dependent electrical resistivity also confirmed that the BiPd single crystal is superconducting at T c =4K. Magneto transport measurements showed that the estimated H c2 (0) value is around 7.0kOe. We also obtained a sharp peak in heat capacity Cp(T) measurements at below 4K due to superconducting ordering. The normalized specific-heat jump, C/γT c , is 1.52, suggesting the BiPd to be an intermediate BCS coupled superconductor. The pressure dependent electrical resistivity shows the T c decreases with increasing applied pressure and the obtained dT c /dP is -0.62K/Gpa.

We report the magneto-conductivity analysis at different temperatures under magnetic field of up to 5Tesla of a well characterized Bi 2 Te 3 crystal. Details of crystal growth and various physical properties including high linear magneto resistance are already reported by some of us. To elaborate upon the transport properties of Bi 2 Te 3 crystal, the magneto conductivity is fitted to the known HLN (Hikami Larkin Nagaoka) equation and it is found that the conduction mechanism is dominated by both surface driven WAL (weak anti localization) and the bulk WL states. The value of HLN equation coefficient (⍺) signifying the type of localization (WL, WAL or both WL and WAL) falls within the range of -0.5 to -1.5. In our case, the low field (±0.25Tesla) fitting of studied crystal exhibited value of ⍺ close to -0.86 for studied temperatures of up to 50K, indicating both WAL and WL contributions. The phase coherence length ( ) is found to decrease from 98.266 to 40.314nm with increasing temperature. Summarily, the short letter reports the fact that bulk Bi 2 Te 3 follows the HLN equation and quantitative analysis of the same facilitates to know the quality of studied crystal in terms of WAL to WL contributions and thus the surface to bulk conduction ratio.

The discovery of Weyl semimetals (WSM) has brought forth the condensed matter realization of Weyl fermions, which were previously theorized as low energy excitations in high energy particle physics. Recently, transition metal mono-pnictides are under intense investigation for understanding properties of inversion-symmetry broken Weyl semimetals. Non-trivial Berry phase and chirality are important markers for characterizing topological aspects of Weyl semimetals. Most recently, theoretical calculations predict strong influence of the position of Weyl nodes with respect to Fermi surface and weak disorder that can drive WSMs into chirally symmetric Dirac semimetals. Using magneto-transport measurements in single crystals of WSM NbP, we observe an exceptionally large magnetoresistance at low temperature, which is non-saturating and linear at high fields. The origin of linear transverse magnetoresistance is assigned to charge carrier mobility fluctuations. Negative longitudinal magnetoresistance is not seen, suggesting lack of well-defined chiral anomaly in NbP. Unambiguous Shubnikov-de Haas oscillations are observed at low temperatures that are correlated to a trivial Berry phase corresponding to Fermi surface extrema at 30.5 Tesla. Our results are important towards identifying topological characteristics of Weyl semimetals and their experimental manifestations in the presence of weak disorder.