Mesoscopic Physics
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| Michael Pustilnik, who worked recently as a Research Associate with Leonid Glazman. |
| photo by Jonathan Chapman |
The Greek word meso means "in between". Mesoscopic Physics refers to the physics of structures of intermediate sizes, ranging from a few atomic radii to a few microns. A mesoscopic sample is too big to study its properties by the methods standard in the physics of individual atoms, and is too small for the application of the familiar physical laws of the macro world. Put another way, a macroscopic device, when scaled down to a meso-size, starts revealing the quantum signatures of conventional characteristics. For example, in the macro world, the conductance of a wire increases continuously with its diameter, but in the meso world the wire's conductance is quantized - i.e., the increases occur in steps. On the fundamental science side, mesoscopic devices are created and studied under various conditions experimentally and theoretically in order to shed new light on the physics of insulators, semiconductors, metals, and superconductors. On the applied science side, mesoscopics is an important area to explore if a whole range of new nano-devices is to ever be built.
Experimentally, mesoscopic research in the department is focused on using scanning tunnel microscopy to investigate electronic states of small metal clusters and nanowires. These structures are fabricated using physical rather than chemical techniques. This work complements Professor Goldman's research on superconducting films.
Theoretical explorations of the mesoscopic world include Professor Leonid Glazman's efforts to understand mesoscopic and low-dimensional interacting electron systems; Professor Anatoly Larkin's current area of interest is in superconducting vortex lattice melting in the presence of pinning; and Professor Alex Kamenev's research is the theory of interacting disordered electronic systems and the theory of cellular automata. Professor Boris Shklovskii, although his interests of late have shifted to biological physics, has contributed much to the field of mescoscopic physics. In 1998, his work on the ground state of a clean two-dimensional electron liquid in a weak magnetic field, in which lower Landau levels are completely filled and the upper spin polarized level is only partially filled, predicted stripes and bubble phases. These phases were later proven experimentally and have gone on to become regarded as the general state of a two-dimensional electron gas in a magnetic field.
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