38,676 research outputs found
Fermi Surfaces, Fermi Patches, and Fermi Arcs in High Tc Superconductors
A defining property of metals is the existence of a Fermi surface: for two
dimensions, a continuous contour in momentum space which separates occupied
from unoccupied states. In this paper, I discuss angle resolved photoemission
data on the cuprate superconductor BSCCO and argue that it is not best thought
of in this conventional picture. Rather, the data are consistent with
``patches'' of finite area connected by more conventional ``arcs''. Novel
physics is associated with the patches, in that the states contained in a patch
are dispersionless and thus interaction dominated. In the pseudogap phase, the
patches are gapped out, leaving the Fermi arcs disconnected. This unusual
situation may be the key to understanding the microscopic physics of the high
temperature superconductors, in that the pairing correlations are strongest in
the patches, yet the superfluid density lives only on the arcs.Comment: 6 pages, AIP Proceedings of the Univ. of Miami HTS99 conferenc
A Tribute to Bill Kruskal
Discussion of ``The William Kruskal Legacy: 1919--2005'' by Stephen E.
Fienberg, Stephen M. Stigler and Judith M. Tanur [arXiv:0710.5063]Comment: Published in at http://dx.doi.org/10.1214/088342306000000358 the
Statistical Science (http://www.imstat.org/sts/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Compression springs used for vibration isolation
System that employs opposed pairs of compression springs can be totally compressed to provide a ''hard mount'' during component installation and adjustment, and can be released to a free-floating condition for vibration isolation during test
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