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Hole dynamics and photoemission in a t-J model for SrCu_2(BO_3)_2

Matthias Vojta
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Abstract

The motion of a single hole in a t-J model for the two-dimensional spin-gap compound SrCu_2(BO_3)_2 is investigated. The undoped Heisenberg model for this system has an exact dimer eigenstate and shows a phase transition between a dimerized and a Neel phase at a certain ratio of the magnetic couplings. We calculate the photoemission spectrum in the disordered phase using a generalized spin-polaron picture. By varying the inter-dimer hopping parameters we find a cross-over between a narrow quasiparticle band regime known from other strongly correlated systems and free-fermion behavior. The hole motion in the Neel-ordered phase is also briefly considered.

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Matthias Vojta. 1999-12-07. Hole dynamics and photoemission in a t-J model for SrCu_2(BO_3)_2. https://doi.org/10.1103/physrevb.61.11309

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