We report the characterization of layered, 2H-type Cu x TaS 2 , for 0 ≤ x ≤ 0.12. The charge density wave (CDW), at 70 K for TaS 2 , is destabilized with Cu doping. The sub-1K superconducting transition in undoped 2H-TaS 2 jumps quickly to 2.5 K at low x, increases to 4.5 K at the optimal composition Cu 0.04 TaS 2 , and then decreases at higher x. The electronic contribution to the specific heat, first increasing and then decreasing as a function of Cu content, is 12 mJ mol -1 K -2 at Cu 0.04 TaS 2 . Electron diffraction studies show that the CDW remains present at the optimal superconducting composition, but with both a changed q vector and decreased coherence length. We present an electronic phase diagram for the system.

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X rays produced during electron-beam deposition of metallic electrodes drastically change the performance of organic spintronic devices. The x rays generate traps with an activation energy of ≈0.5  eV in a commonly used organic. These traps lead to a dramatic decrease in spin-diffusion length in organic spin valves. In organic magnetoresistive (OMAR) devices, however, the traps strongly enhance magnetoresistance. OMAR is an intrinsic magnetotransport phenomenon and does not rely on spin injection. We discuss our observations in the framework of currently existing theories.

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Nanoscale control of the metal-insulator transition of the LaAlO3/SrTiO3 interface with a conductive-atomic force microscope (c-AFM) technique has enabled a variety of electrical and photonic device concepts. While previous devices have demonstrated sub-10 nm critical features, information processing applications also require high operating speeds. Here we show that a “sketched” nanoscale transistor (“SketchFET”) can operate at frequencies in excess of 2 GHz. The combination of high speed and high conductance with a small footprint make these devices and this platform attractive for sub-10 nm computing and storage architectures.