Protected ground states in short chains of coupled spins in circuit quantum electrodynamics
Abstract
The two degenerate ground states of the anisotropic Heisenberg (XY) spin model of a chain of qubits (pseudo-spins) can encode quantum information, but their degree of protection against local perturbations is known to be only partial. We examine the properties of the system in the presence of non-local spin-spin interactions, possibly emerging from the quantum electrodynamics of the device. We find a phase distinct from the XY phase admitting two ground states which are highly protected against all local field perturbations, persisting across a range of parameters. In the context of the XY chain we discuss how the coupling between two ground states can be used to observe signatures of topological edge states in a small controlled chain of superconducting transmon qubits.
Keywords
Cite
@article{arxiv.1602.00299,
title = {Protected ground states in short chains of coupled spins in circuit quantum electrodynamics},
author = {Adam Callison and Eytan Grosfeld and Eran Ginossar},
journal= {arXiv preprint arXiv:1602.00299},
year = {2017}
}
Comments
10 pages, 11 figures