Dynamical decoupling with tailored waveplates for long distance communication using polarization qubits

TL;DR

This paper demonstrates that tailored waveplates implementing dynamical decoupling can effectively preserve polarization qubits over long optical fibers, mitigating dephasing and rotational errors for quantum communication.

Contribution

It introduces a method using tailored waveplates for dynamical decoupling in optical fibers, enhancing polarization qubit fidelity during long-distance transmission.

Findings

Dynamical decoupling maintains high fidelity of polarization qubits.

Tailored waveplates mitigate birefringent noise effects.

Effective against flip-angle errors from finite waveplate widths.

Abstract

We address the issue of dephasing effects in flying polarization qubits propagating through optical fiber by using the method of dynamical decoupling. The control pulses are implemented with half waveplates suitably placed along the realistic lengths of the single mode optical fiber. The effects of the finite widths of the waveplates on the polarization rotation are modeled using tailored refractive index profiles inside the waveplates. We show that dynamical decoupling is effective in preserving the input qubit state with the fidelity close to one when the polarization qubit is subject to the random birefringent noise in the fiber, as well the rotational imperfections (flip-angle errors) due to the finite width of the waveplates.