Quantum information processing in a spin-bus system of coupled chains

TL;DR

This paper proposes a spin-bus system of coupled chains for long-distance quantum information processing, demonstrating how effective interactions enable universal quantum computation with high precision.

Contribution

It introduces a novel spin-bus system of coupled chains that facilitates long-range quantum interactions and universal quantum computation.

Findings

Effective Heisenberg interactions enable long-distance coupling.

Interaction type alternates with node distance, switching between antiferromagnetic and ferromagnetic.

High-precision quantum gate operations are achievable despite quantum fluctuations.

Abstract

The effective Heisenberg interaction of long distance is constructed in spin qubits connected to a bus of two strongly coupled chains. Universal quantum computation can be realized on the basis of the bus which always keeps frozen at the ground state. It is found that the effective interaction is primarily determined by the energy spectra of the bus. With the variation of the distance between two connecting nodes, the interaction alternately occurs between antiferromagnetic and ferromagnetic ones. The long range interaction can also be attained in coupled infinite chains. The quantum gate operations with the high precision are implemented in the condition of quantum fluctuations.