A quantum network distributes quantum entanglements between remote nodes,
which is key to many quantum applications. However, unavoidable noise in
quantum operations could lead to both low throughput and low quality of
entanglement distribution. This paper aims to address the simultaneous
exponential degradation in throughput and quality in a buffered multi-hop
quantum network. Based on an end-to-end fidelity model with worst-case
(isotropic) noise, we formulate the high-fidelity remote entanglement
distribution problem for a single source-destination pair, and prove its
NP-hardness. To address the problem, we develop a fully polynomial-time
approximation scheme for the control plane of the quantum network, and a
distributed data plane protocol that achieves the desired long-term throughput
and worst-case fidelity based on control plane outputs. To evaluate our
algorithm and protocol, we develop a discrete-time quantum network simulator.
Simulation results show the superior performance of our approach compared to
existing fidelity-agnostic and fidelity-aware solutions