Quantum strategies to overcome classical multiplexing limits

Physical Review A, vol. 114

Abstract

Near-term quantum networks face a bottleneck due to low quantum communication rates. This degrades performance both by lowering operating speeds and increasing qubit storage time in noisy memories, making some quantum internet applications infeasible. One way to circumvent this bottleneck is multiplexing: combining multiple signals into a single signal to improve the overall rate. Standard multiplexing techniques are classical in that they do not make use of coherence between quantum channels nor account for decoherence rates that vary during a protocol's execution. In this paper, we first derive semiclassical limits to multiplexing for many-qubit protocols and then introduce two techniques: single click quantum multiplexing and multiserver multiplexing. These can enable beyond-classical multiplexing advantages. We illustrate these techniques through three example applications: (1) entanglement generation between two asymetric quantum network nodes (i.e., repeaters or quantum servers with unequal memories), (2) remote state preparation between many end user devices and a single quantum node, and (3) remote state preparation between one end user device and many internetworked quantum nodes. By utilizing many noisy internetworked quantum devices instead of fewer low-noise devices, our multiplexing strategies enable new paths towards achieving high-speed many-qubit quantum network applications.

Authors 8

1. Tzula B. Propp Aachen

   Leiden University · QuTech · Delft University of Technology

   Affiliation as printed

   Leiden University

   QuTech

   TUDelft

2. Jeroen Grimbergen

   QuTech · Delft University of Technology

   Affiliation as printed

   QuTech

   TUDelft

3. Emil R. Hellebek

   University of Copenhagen

   Affiliation as printed

   Niels Bohr Institute

   University of Copenhagen

4. Junior R. Gonzales-Ureta
   Affiliation as printed

   Q*Bird

5. Janice van Dam

   QuTech · Delft University of Technology

   Affiliation as printed

   QuTech

   TUDelft

6. Joshua A. Slater
   Affiliation as printed

   Q*Bird

7. Anders Søndberg Sørensen

   University of Copenhagen

   Affiliation as printed

   Niels Bohr Institute

   University of Copenhagen

8. Stephanie Wehner

   QuTech · Delft University of Technology

   Affiliation as printed

   QuTech

   TUDelft