Abstract
To build a global quantum-communication network, low-transmission, fiber-based communication channels can be supplemented by using a free-space channel between a satellite and a ground station on Earth. We construct a system that generates hyperentangled photonic "ququarts"and measures them to execute multiple quantum-communication protocols of interest. We successfully execute and characterize superdense teleportation, a modified remote-state preparation protocol that transfers more quantum information than standard teleportation, for the same classical information cost, and moreover, is in principle deterministic. Our measurements show an average fidelity of 0.94±0.02, with a phase resolution of approximately 7∘, allowing reliable transmission of >105 distinguishable quantum states. Additionally, we demonstrate the ability to compensate for the Doppler shift, which would otherwise prevent sending time-bin encoded states from a rapidly moving satellite, thus allowing the low-error execution of phase-sensitive protocols during an orbital pass. Finally, we show that the estimated number of received coincidence counts in a realistic implementation is sufficient to enable faithful reconstruction of the received state in a single pass.
| Original language | English |
|---|---|
| Article number | 014044 |
| Journal | Physical Review Applied |
| Volume | 14 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jul 2020 |
| Externally published | Yes |
Funding
The authors acknowledge Alexander Hill for the suggestion to use a two-sample KS test. Thanks to MIT-Lincoln Laboratory for the orbital simulation calculations. This work is primarily supported by NASA Grant No. NNX13AP35A and NASA Grant No. NNX16AM26G. This work is also supported by a DoD, Office of Naval Research, National Defense Science and Engineering Graduate Fellowship (NDSEG). All authors contributed to experiment design and commented on the paper. H.B. conceptualized SDT protocol. T.G. constructed the initial optical system and wrote the preliminary version of the tomography analysis code. C.K.Z. started upgrade of detection system, implemented Bayesian analysis, and calculated the tomography settings and the contributions to the loss of fidelity. J.C.C. upgraded the optical system and finished upgrade of detection system, and carried out all experiments and MLE data analysis. J.C.C., C.K.Z., and P.G.K. wrote the manuscript.