Simulation of depolarizing channel exploring maximally non separable spin-orbit mode

TL;DR

This work addresses modeling and emulation of the depolarizing channel in quantum information using spin-orbit light modes, introducing a compact linear-optical circuit to simulate depolarization and comparing it with the Solovay-Kitaev decomposition. Theoretical sections establish the channel formalism, spin-orbit mode structure, and coherence metrics, while the experiments demonstrate high-fidelity depolarization and coherence-consistent results, with the compact circuit showing superior robustness. The key contributions include the first experimental depolarizing-channel emulation via SK-decomposition in spin-orbit modes and a simpler, more robust compact-circuit approach that leverages maximally non-separable spin-orbit states. These findings advance photonic quantum-channel benchmarking and enable scalable exploration of depolarizing dynamics in optically encoded qubits.

Abstract

Depolaring Channel is one of the most important noise model and constitute a reliable benchmark quantum information field. In this work we present a simple way to emulate depolaring channel exploring a vector beam in a compact linear optical circuit. The evolution of different states are successfully reproduced. Our results are in excellent agreement compared with the results obtained by the spin-orbit Solovay-Kitaiev decomposiotion for Depolarizing Channel, also presented here for the first time.

Figures (9)

• Figure 1: Contraction of Bloch sphere under depolarizing channel action.
• Figure 2: Logical circuit for one realization PhysRevLett.111.130504.
• Figure 3: Experimental setup. S-plate prepare $\frac{I}{2}$ maximally mixed polarization state. The action os S-plate is showed in the image at superior right part of the image.
• Figure 4: Density Matrices of the state $\rho=\ket{V}\bra{V}$ obtained from the Solovay-Kitaev decomposition. Where (a) is the probability $\lambda'=0$ of the state being depolarized, (b) $\lambda'=0.25$, (c) $\lambda'=0.5$ and (d) $\lambda'=0.75$.
• Figure 5: Density Matrices of the state $\rho=\ket{+}\bra{+}$ obtained from the Solovay-Kitaev decomposition. Where (a) is the probability $\lambda'=0$ of the state being depolarized, (b) $\lambda'=0.25$, (c) $\lambda'=0.5$ and (d) $\lambda'=0.75$.