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dI/dV ( μ S). V ( μ V). Quantum Coherence and Mesoscopic Physics Norman Birge, Michigan State University, DMR-0405238. 1.4 m m. Al. Al. Al tunnel probe. Ag.
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dI/dV (μS) V (μV) Quantum Coherence and Mesoscopic PhysicsNorman Birge, Michigan State University, DMR-0405238 1.4 mm Al Al Al tunnel probe Ag While superconductivity was discovered nearly 100 years ago, physicists continue to discover new things that superconductors can do. In the submicron sample shown in the upper picture, supercurrent passes from left to right between the two aluminum (Al) electrodes while normal current is injected into the silver (Ag) electrode from below. Under these conditions, the electrons in the silver wire populate their energy states in a very strange way. We used tunneling spectroscopy to probe the energy distribution of populated electron states, which in turn revealed the energy spectrum of supercurrent-carrying states in the Ag wire. Differential conductance of tunnel probe M.S. Crosser et al., Physical Review Letters 96, 167004 (2006).
Quantum Coherence and Mesoscopic PhysicsNorman Birge, Michigan State University, DMR-0405238 Broad scientific impact:Understanding the basic states of matter, such as magnetism and superconductivity, still plays a central role in condensed matter physics. New techniques for controlling materials on the nanoscale may lead to new technological applications. Education:Graduate students working in experimental condensed matter physics learn the concepts and experimental tools that are crucial to the future development and applications of nanosciences. Former graduate students from this NSF-sponsored research program have gone on to careers in academia, industry, and government labs. Undergraduate students working in the lab get valuable research experience that helps them choose an appropriate career path. Current & recent graduate students:Michael Crosser, Ion Moraru, Gassem Al-Zoubi Current & recent undergrads:Hamood Arham, Kathy Walsh, Mark Stockett Strange features in the energy distribution of electrons, induced by simultaneous normal and supercurrent. M.S. Crosser et al., Phys. Rev. Lett. 96, 167004 (2006).