Meenakshi Singh

Interplay between topological insulators and superconductors

Modern methods of in situ transmission electron microscopy (TEM) allow one to not only manipulate with a nanoscale object at the nanometer-range precision but also to get deep insights into its physical and chemical statuses. Dedicated TEM holders combining the capabilities of a conventional high-resolution TEM instrument and atomic force -, and/or scanning tunneling microscopy probes become the powerful tools in nanomaterials analysis. This progress report highlights the past, present and future of these exciting methods based on the extensive authors endeavors over the last five years. The objects of interest are diverse. They include carbon, boron nitride and other inorganic one- and two-dimensional nanoscale materials, e.g., nanotubes, nanowires and nanosheets. The key point of all experiments discussed is that the mechanical and electrical transport data are acquired on an individual nanostructure level under ultimately high spatial, temporal and energy resolution achievable in TEM, and thus can directly be linked to morphological, structural and chemical peculiarities of a given nanomaterial.

Superconductivity in single crystalline Pb nanowires contacted by normal metal electrodes

The transport properties of superconducting single crystal Pb nanowires that are 55 and 70 nm in diameter were studied by the standard four-electrode method. With normal metal electrodes, resistance-temperature and resistance-magnetic field scans show a series of resistance steps with increasing temperature and magnetic field as the wires are brought toward the normal state. The resistance-current (

Voltage-current properties of superconducting amorphous tungsten nanostrips.

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Electrostatically defined silicon quantum dots with counted antimony donor implants

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Electronic transport properties of topological insulator films and low dimensional superconductors

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Transport properties of topological insulators films and nanowires

) scans at different temperatures and magnetic fields show that the increase in

Antiproximity effect in aluminum nanowires with no applied magnetic field

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Dynamo transition in low-dimensional models

with

Ion implantation for deterministic single atom devices

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Quantum transport in topological insulator hybrid structures—A combination of topological insulator and superconductor

is punctuated with sharp steps at specific current values. A large residual resistance is observed down to 2 K. The origin of these phenomena is related to the inhomogeneity and proximity effect from the normal electrodes.