Time optimal information transfer in spintronics networks

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-$\frac{1}{2}$ 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.

accepted for CDC 2015

References in corpus (5)

• Evolutionary Algorithms for Hard Quantum Control
• Fast, high fidelity information transmission through spin chain quantum wires
• Quantum networks: Anti-core of spin chains
• Characterization and Control of Quantum Spin Chains and Rings
• Information Transfer Fidelity in Spin Networks and Ring-based Quantum Routers

Cited by in corpus (10)

• Design of Feedback Control Laws for Information Transfer in Spintronics Networks
• Quantum control for high-fidelity multi-qubit gates
• Jonckheere-Terpstra test for nonclassical error versus log-sensitivity relationship of quantum spin network controllers
• Structured singular value analysis for spintronics network information transfer control
• Robustness of energy landscape control for spin networks under decoherence
• Multi-fractal Geometry of Finite Networks of Spins
• Robustness of Energy Landscape Control to Dephasing
• Time Domain Sensitivity of the Tracking Error
• Reinforcement Learning vs. Gradient-Based Optimisation for Robust Energy Landscape Control of Spin-1/2 Quantum Networks
• Sensitivity and Robustness of Quantum Spin-1/2 Rings to Parameter Uncertainty