arXiv:cond-mat/9803126 · Physical Review Letters
Fermi Surface Evolution, Pseudogap, and Staggered Gauge Field Fluctuations in Underdoped Cuprates
Xi Dai, Zhao-Bin Su
Abstract
In the context of the $t\ensuremath{-}J$ model, we show that besides the long wave length gauge field fluctuation, an additional low energy fluctuation, i.e., the staggered gauge field fluctuation, plays a crucial role in the underdoped regime. Including the staggered gauge field fluctuation, we calculate the spectral function. The line shape near $(\ensuremath{\pi},0)$ is very broad in the underdoped case and is quite sharp in the overdoped case. The quasiparticle peaks near $(0.5\ensuremath{\pi},0.5\ensuremath{\pi})$ are always very sharp in both cases. We also calculate the Fermi surface (FS) crossover from a small four-segment-like FS to a large continuous FS. The pseudogap extracted from the photoemission data can be also interpreted by our calculation.