Quantum simulation via filtered Hamiltonian engineering: application to perfect quantum transport in spin networks

TL;DR

This paper introduces a Hamiltonian engineering method that enables perfect quantum transport in spin networks without local control, using collective rotations and field gradients, suitable for room-temperature quantum devices.

Contribution

The authors present a novel collective control technique for Hamiltonian engineering that achieves perfect quantum transport in complex spin networks without local manipulation.

Findings

Achieves spatially modulated couplings via dynamical construction.

Demonstrates perfect quantum information transport in spin chains.

Robustness improved with a new apodization scheme.

Abstract

We propose a method for Hamiltonian engineering in quantum information processing architectures that requires no local control, but only relies on collective qubit rotations and field gradients. The technique achieves a spatial modulation of the coupling strengths via a dynamical construction of a weighting function combined with a Bragg grating. As an example, we demonstrate how to generate the ideal Hamiltonian for perfect quantum information transport between two separated nodes of a large spin network. We engineer a spin chain with optimal couplings from a large spin network, such as naturally occurring in crystals, while decoupling all unwanted interactions. For realistic experimental parameters, our method can be used to drive perfect quantum information transport at room-temperature. The Hamiltonian engineering method can be made more robust under coherence and coupling disorder by a novel apodization scheme. Thus the method is quite general and can be used engineer the Hamiltonian of many complex spin lattices with different topologies and interactions.