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Intermediate-Coupling Theory for the Spectral Weight of Spin Polaron

Min-Fong Yang
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Abstract

Within the intermediate-coupling theory, the quasiparticle weight $Z$ of one hole injected in the undoped antiferromagnetic ground state is studied. We find that, for the hole located at the quasiparticle band minimun with momentum ${\bf k}_0 = (\pm \fracπ{2}, \pm \fracπ{2})$, $Z$ is finite. By comparing the results obtained by the self-consistent Born approximation, we show that the intermediate-coupling theory for $Z$ is appropriate only when $J/t \stackrel{>}{\sim} 1.6$. Finally, the reason why this approach fails in the small-$J$ case will also be clarified.

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Min-Fong Yang. 1996-07-29. Intermediate-Coupling Theory for the Spectral Weight of Spin Polaron. https://doi.org/10.1103/physrevb.55.56

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