activity
20242026
collaborators

6 papers

math-ph2026

On the gauge invariant boundary condition in open XXZ chains: SoV bases, elementary blocks and overlaps

G. Niccoli, V. Terras

We consider the open XXZ spin chain with unparallel boundary fields, in the special case in which the Vertex-IRF transform of the K-matrix labelling the boundary field at site 1 is…

math-ph2025

On correlation functions for the open XXZ chain with non-longitudinal boundary fields : the case with a constraint

G. Niccoli, V. Terras

This paper is a continuation of [1], in which a set of matrix elements of local operators was computed for the XXZ spin-1/2 open chain with a particular case of unparallel boundary…

math-ph2025

Correlation functions for open XXZ spin 1/2 quantum chains with unparallel boundary magnetic fields

G. Niccoli, V. Terras

In this paper we continue our derivation of the correlation functions of open quantum spin 1/2 chains with unparallel magnetic fields on the edges; this time for the more involved…

math-ph2025

The open XYZ spin 1/2 chain: Separation of Variables and scalar products for boundary fields related by a constraint

G. Niccoli, V. Terras

We consider the open XYZ spin chain with boundary fields. We solve the model by the new Separation of Variables approach introduced in arXiv:1904.00852. In this framework, the tran…

math-ph2025

On correlation functions of the open XYZ spin 1/2 chain with boundary fields related by a constraint

G. Niccoli, V. Terras

In this paper, we consider the quantum XYZ open spin-1/2 chain with boundary fields. We focus on the particular case in which the six boundary parameters are related by a single co…

math-ph2024

Boundary overlap in the open XXZ spin chain

Charbel Abetian, Nikolai Kitanine, Veronique Terras

In this paper we compute the overlaps of the ground states for the open spin chains after a change of one of the boundary magnetic fields. It can be considered as the first step to…