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Coupling angle resolved photoemission data and quasiparticle structure in antiferromagnetic insulators Sr2CuO2Cl2 and Ca2CuO2Cl2

V. Gavrichkov·S. Ovchinnikov·A. Borisov
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Abstract

We have analyzed the quasiparticle dispersion and ARPES-spectral density for Sr2CuO2Cl2 and Ca2CuO2Cl2 antiferromagnetic insulators along basic symmetric directions of the Brillouin zone (BZ) in a framework of an extended tight binding method (ETBM) with explicit account for intracell strong electron correlations. The quasiparticle dispersion is in a good agreement with ARPES- data. At the top of valence band we found a narrow impurity-like virtual level with the spectral weight proportional to the concentration of spin fluctuations. A pseudogap between the virtual level and the top of the valence band has dispersion similar to 'remnant Fermi surface' in Ca2CuO2Cl2 and to a pseudogap in the underdoped Bi2212 samples. A calculated parity of the polarized ARPES-spectra in (0,0),(pi/2,pi/2),(pi,0) - points in the AFM- phase is even with regard to relative magnitudes of the partial contributions by different orbitals to the total ARPES- spectral density. Conditions of an observability for the different partial contributions in the polarized ARPES- experiments are determined also.

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V. Gavrichkov, S. Ovchinnikov, A. Borisov. 2001-04-09. Coupling angle resolved photoemission data and quasiparticle structure in antiferromagnetic insulators Sr2CuO2Cl2 and Ca2CuO2Cl2. https://doi.org/10.1103/physrevb.64.235124

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