Quantum (Oct 2024)

Quantum teleportation implies symmetry-protected topological order

  • Yifan Hong,
  • David T. Stephen,
  • Aaron J. Friedman

DOI
https://doi.org/10.22331/q-2024-10-10-1499
Journal volume & issue
Vol. 8
p. 1499

Abstract

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We constrain a broad class of teleportation protocols using insights from locality. In the ``standard'' teleportation protocols we consider, all outcome-dependent unitaries are Pauli operators conditioned on linear functions of the measurement outcomes. We find that all such protocols involve preparing a ``resource state'' exhibiting symmetry-protected topological (SPT) order with Abelian protecting symmetry $\mathcal{G}_{k}= (\mathbb{Z}^{ }_2 \times \mathbb{Z}^{ }_2)^k$. The $k$ logical states are teleported between the edges of the chain by measuring the corresponding $2k$ string order parameters in the bulk and applying outcome-dependent Paulis. Hence, this single class of nontrivial SPT states is both necessary and sufficient for the standard teleportation of $k$ qubits. We illustrate this result with several examples, including the cluster state, variants thereof, and a nonstabilizer hypergraph state.