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

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.

4 pages, 3 figs

References in corpus (1)

• Exact Demonstration of Magnetization Pleateaus and First Order Dimer-Néel Phase Transitions in a Modified Shastry-Sutherland Model for SrCu${}_2$(BO${}_3$)${}_2$

Cited by in corpus (3)

• Indications of Spin-Charge Separation at Short Distance and Stripe Formation in the Extended t-J Model on Ladders and Planes
• Spin-polaron excitations in a doped Shastry-Sutherland model
• Hole Dynamics in the Orthogonal-Dimer Spin System