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Condensed Matter Physics Commons

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Full-Text Articles in Condensed Matter Physics

Refrigerator With Phonon Filters: An Application Of The Phonon Deficit Effect In Superconducting Tunnel Junctions, G. G. Melkonyan, Armen Gulian Sep 2003

Refrigerator With Phonon Filters: An Application Of The Phonon Deficit Effect In Superconducting Tunnel Junctions, G. G. Melkonyan, Armen Gulian

Mathematics, Physics, and Computer Science Faculty Articles and Research

Nonequilibrium phenomena in thin solid films can result in cooling effects. These types of effects were predicted theoretically a while ago, and only recently were demonstrated experimentally in superconductor-insulator-normal metal (SIN) tunnel junctions. Since then, there is a growing interest in tunneling effects for the purpose to develop on-chip refrigerators. Thin film devices have the advantage of being extremely compact, operate in a continuous mode, dissipate little power, and can easily be integrated in cryogenic detectors. Currently these refrigerators can generate cooling in the order of 100 mK in an environment of 0.3–0.5 K. There are reasons to expect that …


Triplet Superconductors From The Viewpoint Of Basic Elements For Quantum Computers, Armen M. Gulian, Kent S. Wood Jul 2003

Triplet Superconductors From The Viewpoint Of Basic Elements For Quantum Computers, Armen M. Gulian, Kent S. Wood

Mathematics, Physics, and Computer Science Faculty Articles and Research

We discuss possibilities of utilizing superconductors with Cooper condensates in triplet pairing states (where the spin of condensate pairs is S=1) for practical realization of quantum computers. Superconductors with triplet pairing condensates have features that are unique and cannot be found in the usual (singlet pairing, S=0) superconductors. The symmetry of the order parameter in some triplet superconductors (e.g., ruthenates) corresponds to doubly-degenerate chiral states. These states can serve as qubit base states for quantum computing.


Thermoelectric Cooling At Cryogenic Temperatures, S. R. Harutyunyan, V. H. Vardanyan, A. S. Kuzanyan, V. R. Nikoghosyan, S. Kunii, K. S. Wood, Armen Gulian Jan 2003

Thermoelectric Cooling At Cryogenic Temperatures, S. R. Harutyunyan, V. H. Vardanyan, A. S. Kuzanyan, V. R. Nikoghosyan, S. Kunii, K. S. Wood, Armen Gulian

Mathematics, Physics, and Computer Science Faculty Articles and Research

Experimental results demonstrating Peltier cooling below 10 K are reported, using crystals of the thermoelectric cerium hexaboride (CeB6). Direct measurements of the Peltier cooling showed δT up to ∼0.2 K in magnitude at T∼4–5 K. All three kinetic parameters: resistivity (ρ), heat conductivity (k), and Seebeck coefficient (S), characterizing the thermoelectric figure of merit ZT=S2T/ρk, were measured, giving high-confidence results.