Physics – Condensed Matter – Strongly Correlated Electrons
Scientific paper
2007-02-12
Phys. Rev. B 75, 035106 (2007)
Physics
Condensed Matter
Strongly Correlated Electrons
10 two-column pages, 12 figures
Scientific paper
10.1103/PhysRevB.75.035106
The aim of the present paper is twofold. The first goal is to show that high resolution angle-resolved photoelectron spectra from cuprates indicate the presence of string-like excitations of the quasihole excitation in a quantum antiferromagnet. In order to compare with the experimental intensity plots, we calculate the spectral function of the t-J and the t-t'-t"-J models within the self-consistent Born approximation for widely accepted values of the parameters of these models. The main features of the high resolution photoelectron spectra are in general agreement with the results based on the above models and can be understood by considering not only the lowest energy quasiparticle peak but, also, the higher energy string-like excitations of the hole. The second goal of the present paper is to make the case that a proper analysis of both the numerical results obtained from these models and of the experimental results, suggests a theoretical picture for the internal structure of the hole-quasiparticle and a string-exchange pairing mechanism due to strong antiferromagnetic correlations among the background spins. We find that, using a simple model in which the Hilbert space is restricted to states of only unbroken strings attached to the holes and in which the holes are connected with unbroken strings, we can provide a good quantitative description of the most accurate numerical results. We find that the holes experience an effective interaction due to a string-exchange mechanism which is characterized by a rather large string tension and this can provide pairing energy scales much larger that those suggested by spin-fluctuation mediated pairing models. In addition, it is argued that such string-exchange interaction tends to bind holes in a bound state with the $d_{x^2-y^2}$ symmetry.
No associations
LandOfFree
String excitations of a hole in a quantum antiferromagnet and photoelectron spectrospopy does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with String excitations of a hole in a quantum antiferromagnet and photoelectron spectrospopy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and String excitations of a hole in a quantum antiferromagnet and photoelectron spectrospopy will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-409273