Quantum teleportation in nonequilibrium environments and fixed-point fidelity

Quantum teleportation, a fundamental protocol in quantum information science, enables the transfer of quantum states through entangled particle pairs and classical communication channels. While ideal quantum teleportation requires maximally entangled states as resources, real-world implementations inevitably face environmental noise and decoherence effects. In this work, we investigate quantum teleportation in nonequilibrium environments with different temperatures or chemical potentials. We employ the Bloch-Redfield equation to characterize the nonequilibrium dynamics in both bosonic and fermionic reservoirs. Our analysis reveals that nonequilibrium conditions, namely, the temperature difference and chemical potential difference, can significantly enhance the teleportation fidelity beyond what is achievable in equilibrium scenarios. Notably, under certain nonequilibrium conditions, the fidelities for all input states converge to the same value. We term this behavior the teleportation with a fixed-point fidelity. Importantly, at this fixed point, fidelity can be further enhanced by tuning the nonequilibrium parameters. These findings offer crucial insights for the implementation of quantum communication protocols in realistic environments, demonstrating that nonequilibrium conditions not only improve the fidelity but also present a promising avenue for simplifying practical quantum teleportation schemes.