Measurement-based quantum computer in the gapped ground state of a two-body Hamiltonian

TL;DR

This paper introduces a measurement-based quantum computing scheme where logical qubits are encoded in the gapped ground state of a spin-1 chain, providing robustness against noise and enabling computation through single-spin measurements.

Contribution

It presents a novel ground-code measurement-based quantum computer scheme using two-body interactions in a spin-1 chain, enhancing noise resilience and operational feasibility.

Findings

Logical qubits encoded in gapped ground states for noise protection

Implementation feasible with trapped atoms or polar molecules in optical lattices

Expected gap sizes of up to 4.8 kHz for practical realization

Abstract

We propose a scheme for a ground-code measurement-based quantum computer, which enjoys two major advantages. First, every logical qubit is encoded in the gapped degenerate ground subspace of a spin-1 chain with nearest-neighbor two-body interactions, so that it equips built-in robustness against noise. Second, computation is processed by single-spin measurements along multiple chains dynamically coupled on demand, so as to keep teleporting only logical information into a gap-protected ground state of the residual chains after the interactions with spins to be measured are turned off. We describe implementations using trapped atoms or polar molecules in an optical lattice, where the gap is expected to be as large as 0.2 kHz or 4.8 kHz respectively.