Remotely Preparing Many Qubits with a Single Photon

arXiv (Cornell University)

Abstract

A single photon in a superposition of $d$ modes naturally encode a $d$-dimensional quantum system, a so-called qudit. We show that such superpositions can be leveraged to achieve a quantum speed-up of remote remote state preparation (RSP): a primitive for several quantum network protocols. For a superposition over $d\geq 2$ modes, the photon state can encode up to ${\rm Log}_2(d)$ qubits, which we exploit in a proposed reflection based RSP protocol with multiple variations. For single qubit RSP, we achieve a performance comparable to the best known existing schemes but with reduced requirements for phase stabilization. For many qubit RSP the achievable success rates remain high despite needing exponentially many temporal modes, since only one photon needs to be transmitted and detected to prepare multiple qubits. By simultaneously preparing many qubits at once, we bypass limited qubit lifetimes limited qubit lifetimes and improve fidelities beyond what is achievable with existing RSP protocols.

Authors 4

1. Tzula B. Propp Aachen

   Leiden University · University of Applied Sciences Leiden

   Affiliation as printed

   Leiden Institute of Physics Leiden University , 2333 CA Leiden , The Netherlands

   QuTech , Kavli Institude of Nanoscience TUDelft , Lorentzweg 1 , 2628 CJ Delft , Netherlands

2. Benedikt Tissot

   University of Copenhagen

   Affiliation as printed

   Center for Hybrid Quantum Networks (Hy -Q) , Niels Bohr Institute , University of Copenhagen , Jagtvej 155A , Copenhagen DK-2200 , Denmark

3. Anders S. Sørensen

   University of Copenhagen

   Affiliation as printed

   Center for Hybrid Quantum Networks (Hy -Q) , Niels Bohr Institute , University of Copenhagen , Jagtvej 155A , Copenhagen DK-2200 , Denmark

4. Stephanie Wehner
   Affiliation as printed

   QuTech , Kavli Institude of Nanoscience TUDelft , Lorentzweg 1 , 2628 CJ Delft , Netherlands