Abstract
We show, by use of angle-resolved photoemission spectroscopy, that underdoped appears to have a large Fermi surface centered at , even for samples with a as low as 15 K. No clear evidence of a Fermi surface pocket around has been found. These conclusions are based on a determination of the minimum gap locus in the pseudogap regime , which is found to coincide with the locus of gapless excitations in momentum space (Fermi surface) determined above . These results suggest that the pseudogap is more likely of precursor pairing rather than magnetic origin.
- Received 5 November 1996
DOI:https://doi.org/10.1103/PhysRevLett.78.2628
©1997 American Physical Society