Fast and robust control of two interacting spins

TL;DR

This paper introduces a fast, robust control method for two interacting spins using shortcuts to adiabaticity, enabling high-fidelity state manipulation and entanglement generation with error suppression.

Contribution

It presents a novel inverse design approach for magnetic fields controlling two spins, optimizing speed and robustness against errors and anisotropic interactions.

Findings

Efficient spin flip and Bell state generation demonstrated.

Designed protocols suppress control errors and unwanted transitions.

Method extends to multiple spins and other quantum systems.

Abstract

Rapid preparation, manipulation, and correction of spin states with high fidelity are requisite for quantum information processing and quantum computing. In this paper, we propose a fast and robust approach for controlling two spins with Heisenberg and Ising interactions. By using the concept of shortcuts to adiabaticity, we first inverse design the driving magnetic fields for achieving fast spin flip or generating the entangled Bell state, and further optimize them with respect to the error and fluctuation. In particular, the designed shortcut protocols can efficiently suppress the unwanted transition or control error induced by anisotropic antisymmetric Dzyaloshinskii-Moriya exchange. Several examples and comparisons are illustrated, showing the advantages of our methods. Finally, we emphasize that the results can be naturally extended to multiple interacting spins and other quantum systems in an analogous fashion.