Time independent quantum circuits with local interactions

TL;DR

This paper proposes a scalable quantum computing scheme using Heisenberg spin chains with local interactions, enabling universal quantum gates without external control, thus simplifying hardware requirements for large quantum circuits.

Contribution

It introduces a static quantum computation method utilizing local interactions in spin chains, improving previous schemes by replacing non-local interactions with local ones mediated by an ancillary chain.

Findings

Achieved universal quantum gates with local interactions

Enhanced scalability for quantum circuit construction

Replaced non-local interactions with local mediated interactions

Abstract

Heisenberg spin chains can act as quantum wires transferring quantum states either perfectly or with high fidelity. Gaussian packets of excitations passing through dual rails can encode the two states of a logical qubit, depending on which rail is empty and which rail is carrying the packet. With extra interactions in one or between different chains, one can introduce interaction zones in arrays of such chains, where specific one or two qubit gates act on any qubit which passes through these interaction zones. Therefore universal quantum computation is made possible in a static way where no external control is needed. This scheme will then pave the way for a scalable way of quantum computation where specific hardwares can be connected to make large quantum circuits. Our scheme is an improvement of a recent scheme where we have achieved to borrow an idea from quantum electrodynamics to replace non-local interactions between spin chains with local interactions mediated by an ancillary chain.