Transmission of polarization quantum state through a fiber optic channel by swapped time-bin state

Abstract

The time-bin quantum state is known to be highly robust against decoherence effects in both fiber-optic and atmospheric channels, a unique feature that renders the time degree of freedom (DOF) more appropriate for quantum communication in these channels. In this paper, we present a scheme to deliver with high fidelity an arbitrary, unknown quantum state in polarization or spatial DOFs over a stochastic channel without need for compensation. The sender swaps the polarization or spatial quantum state for a time-bin state of the photon before signaling it over the random channel, and the receiver swaps the state back. Because the signaled photon is assumed to be in a single spatial or polarization mode, no modal-dependent channel effects perturb the time-bin state. We find that by migration to the time bin, the fidelity of the transferred state is boosted by a margin dependent on the time-bin period and the standard deviations of the statistical parameters of the channel.