Southwest Quantum Information and Technology

Quantum Telecloning on NISQ Computers

Presenting Author: Elijah Pelofske, Los Alamos National Laboratory
Contributing Author(s): Andreas Bärtschi, Bryan Garcia, Boris Kiefer, Stephan Eidenbenz

Due to the no-cloning theorem, generating perfect quantum clones of an arbitrary unknown quantum state is not possible, however approximate quantum clones can be constructed. Quantum telecloning is a protocol that originates from a combination of quantum teleportation and quantum cloning. Here we present \(1 \rightarrow 2\) and \(1 \rightarrow 3\) quantum telecloning circuits, with and without ancilla, that are theoretically optimal (meaning the clones have the highest fidelity allowed by quantum mechanics), universal (the clone fidelity is independent of the state being cloned), and symmetric (the clones all have the same fidelity). We implement these circuits on gate model IBMQ and Quantinuum NISQ hardware. The fidelity of the clones is quantified efficiently using parallel single qubit state tomography instead of performing full state tomography of the telecloning state. Quantum telecloning using mid-circuit measurement in conjunction classical if statements is demonstrated on the Quantinuum H1-2 device. Two alternative implementations of quantum telecloning, deferred measurement and post selection, are demonstrated on ibmq\_montreal, where mid-circuit measurements with real time if statements are not available. The Quantinuum H1-2 device running the telecloning circuits without ancilla achieved a mean clone fidelity of \(0.824\) for two clones (out of a theoretical maximum of \(\frac{5}{6}\)) and \(0.765\) for three clones (out of a theoretical maximum of \(\frac{7}{9}\)).

Read this article online: https://arxiv.org/abs/2205.00125

(Session 5 : Thursday from 5:00 pm - 7:00 pm)