Time optimal information transfer in spintronics networks

TL;DR

This paper investigates how to optimize the transfer of information in spintronics networks, focusing on uniform spin rings, by analyzing eigenstructure conditions and potential configurations to maximize transfer fidelity efficiently.

Contribution

It introduces a method to optimize spin-based information transfer by identifying eigenstructure conditions and selecting suitable potentials, improving control solutions in spin networks.

Findings

Eigenvalue and eigenvector conditions are crucial for maximizing transfer fidelity.

Optimized potential structures significantly enhance transfer success.

Eigenstructure-based control strategies outperform generic approaches.

Abstract

Propagation of information encoded in spin degrees of freedom through networks of coupled spins enables important applications in spintronics and quantum information processing. We study control of information propagation in networks of spin-$\tfrac{1}{2}$ particles with uniform nearest neighbour couplings forming a ring with a single excitation in the network as simple prototype of a router for spin-based information. Specifically optimising spatially distributed potentials, which remain constant during information transfer, simplifies the implementation of the routing scheme. However, the limited degrees of freedom makes finding a control that maximises the transfer probability in a short time difficult. We show that the structure of the eigenvalues and eigenvectors must fulfill a specific condition to be able to maximise the transfer fidelity, and demonstrate that a specific choice among the many potential structures that fulfill this condition significantly improves the solutions found by optimal control.