Perfect state transfer on hypercubes and its implementation using superconducting qubits

TL;DR

This paper presents a protocol for perfect quantum state transfer in hypercubes and proposes a superconducting qubit-based physical implementation with high fidelity, including error bounds.

Contribution

It introduces a switching protocol for perfect state transfer in hypercubes and a practical superconducting qubit architecture for near-perfect fidelity.

Findings

Protocol achieves perfect state transfer in hypercubes.

Superconducting qubit architecture enables high-fidelity implementation.

Error bounds quantify fidelity loss due to implementation faults.

Abstract

We propose a protocol for perfect state transfer between any pair of vertices in a hypercube. Given a pair of distinct vertices in the hypercube we determine a sub-hypercube that contains the pair of vertices as antipodal vertices. Then a switching process is introduced for determining the sub-hypercube of a memory enhanced hypercube that facilitates perfect state transfer between the desired pair of vertices. Furthermore, we propose a physical architecture for the pretty good state transfer implementation of our switching protocol with fidelity arbitrary close to unity, using superconducting transmon qubits with tunable couplings. The switching is realised by the control over the effective coupling between the qubits resulting from the effect of ancilla qubit couplers for the graph edges. We also report an error bound on the fidelity of state transfer due to faulty implementation of our protocol.