Quantum computational webs

TL;DR

This paper introduces quantum computational webs, a new framework for measurement-based quantum computation using simple, physically realizable building blocks, and provides a complete classification of these resources.

Contribution

It presents the concept of quantum computational webs, classifies qubit wires, and discusses physical realizations using common interactions like Ising or exchange.

Findings

Complete classification of qubit wires.

Universal measurement-based quantum computation framework.

Potential physical implementations in superlattices.

Abstract

We introduce the notion of quantum computational webs: These are quantum states universal for measurement-based computation which can be built up from a collection of simple primitives. The primitive elements - reminiscent of building blocks in a construction kit - are (i) states on a one-dimensional chain of systems ("computational quantum wires") with the power to process one logical qubit and (ii) suitable couplings which connect the wires to a computationally universal "web". All elements are preparable by nearest-neighbor interactions in a single pass - a type of operation well-suited for a number of physical architectures. We provide a complete classification of qubit wires. This is first instance where a physically well-motivated class of universal resources can be fully understood. Finally, we sketch possible realizations in superlattices, and explore the power of coupling mechanisms based on Ising or exchange-interactions.