Finite-size Gap, Magnetization, and Entanglement of Deformed Fredkin Spin Chain

Understand

We investigate ground- and excited-state properties of the deformed Fredkin spin chain proposed by Salberger, Zhang, Klich, Korepin, and the authors.

• This model is a one-parameter deformation of the Fredkin spin chain, whose Hamiltonian is $3$-local and translationally invariant in the bulk.
• The model is frustration-free and its unique ground state can be expressed as a weighted superposition of colored Dyck paths.
• We focus on the case where the deformation parameter $t>1$.