On the logarithmic bipartite fidelity of the open XXZ spin chain at $\Delta =-1/2$

Abstract

The open XXZ spin chain with the anisotropy $\Delta =-\frac{1}{2}$ and a one-parameter family of diagonal boundary fields is studied at finite length. A determinant formula for an overlap involving the spin chain's ground-state vectors for different lengths is found. The overlap allows one to obtain an exact finite-size formula for the ground state's logarithmic bipartite fidelity. The leading terms of its asymptotic series for large chain lengths are evaluated. Their expressions confirm the predictions of conformal field theory for the fidelity.

Revised version, 31 pages, 2 figures

References in corpus (5)

• Universal behavior of a bipartite fidelity at quantum criticality
• Sum rules for the ground states of the O(1) loop model on a cylinder and the XXZ spin chain
• Open boundary Quantum Knizhnik-Zamolodchikov equation and the weighted enumeration of Plane Partitions with symmetries
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• The open XXZ chain at $\Delta =-1/2$ and the boundary quantum Knizhnik-Zamolodchikov equations

Cited by in corpus (1)

• Absence of logarithmic enhancement in the entanglement scaling of free fermions on folded cubes