Entanglement dynamics and fractional quantum state transport in the spin-$\frac{1}{2}$ triangular plaquette

TL;DR

This paper explores entanglement dynamics and fractional quantum state transfer in a spin-1/2 triangular plaquette with spin-orbit coupling, revealing discrete transfer times and conditions for forbidden transfer, linking to time crystalline symmetry.

Contribution

It introduces a novel spin-1/2 triangular plaquette model exhibiting fractional quantum state transfer and explores its entanglement dynamics and symmetry-breaking phenomena.

Findings

Quantum state transfer occurs at discrete times with fractional exchange interactions.

Special magnetic interactions can suppress entanglement propagation.

The system links time crystallinity with symmetry breaking phenomena.

Abstract

The dramatic growth of research areas within the province of quantum state transmission (QST) is rapidly accelerating. An important insight to understand the process of QST can be fulfilled by considering the dynamical behavior of its entanglement content. One well-established approach to continuously transfer quantum states is utilizing spin structures. Here, from the view of entanglement propagation, we disclose the signature of fractional QST possibilities. In the present work, we proposed a form of spin-$\frac{1}{2}$ triangular plaquette whose Hamiltonian entails the spin-orbit coupling on the rungs and exchange interaction over the legs. The feature of such a system is that the time instants of QST emerge in a discrete fashion, thereby the values of exchange interactions associated with these moments behave fractionally. Importantly, it is found that for special values of magnetic interaction, QST has singularity i.e., the entanglement propagation is forbidden. In addition, the finite-size nature of this system makes it possible for us to read the nexus between time crystallinity and symmetry breaking. The development of our knowledge about time crystalline symmetry and its breaking helps us to understand the defined concept and fundamental physics of this phenomenon.