DMFT Study on the Electron–hole Asymmetry of the Electron Correlation Strength in the High T_c Cuprates

Abstract

Recent experiments revealed a striking asymmetry in the phase diagram of the high temperature cuprate superconductors. The correlation effect seems strong in the hole-doped systems and weak in the electrondoped systems. On the other hand, a recent theoretical study shows that the interaction strengths (the Hubbard U ) are comparable in these systems. Therefore, it is difficult to explain this asymmetry by their interaction strengths. Given this background, we analyze the one-particle spectrum of a single band model of a cuprate superconductor near the Fermi level using the dynamical mean field theory. We find the difference in the "visibility" of the strong correlation effect between the hole-and electron-doped systems. This can explain the electron-hole asymmetry of the correlation strength without introducing the difference in the interaction strength.

Electron-hole symmetry in quasiparticle spectral weight of cuprates observed via infrared and photoemission spectroscopy

“…In this picture, the smaller effective U in NCCO than in LSCO yields the larger N eff /Cu in NCCO than in LSCO. Similar scenarios have also been suggested by other theoretical works 10,18,34 Lastly, it should be interesting to note that Nd and Pr have magnetic moments while La does not. Because PLCCO has a relatively higher ratio of the non-magnetic La element than NCCO or PCCO, the formation of a 3-dimensional antiferromagnetic phase is more difficult in PLCCO than in NCCO or PCCO.…”

“…. Electrostatically, it means that the electron-doped system with the T' structure lacks the apical oxygen, which effectively reduces the correlation strength U/t, where t is the hopping parameter34 . From this perspective, because the longer Cu-O bonding length of PLCCO than NCCO can provide a larger effective correlation strength (U/t) because of the smaller t, the carriers will be more localized, leading to a smaller N eff /Cu in PLCCO than in NCCO.…”