paper / stephaniewehner / 7d ago
This paper introduces a novel remote state preparation (RSP) protocol utilizing single photons encoded as qudits across multiple temporal modes. This method enables the simultaneous preparation of multiple qubits, demonstrating a quantum speed-up for RSP. The approach offers improved success rates and fidelities for many-qubit preparation compared to existing methods, while reducing phase stabilization requirements for single-qubit RSP.
quantum-computingquantum-networksqubitsremote-state-preparationphotonic-systemsquantum-speedup
“A single photon in a superposition of d modes (qudit) can encode up to Log2(d) qubits.”
paper / stephaniewehner / Feb 16
This paper introduces and benchmarks a probabilistic cutoff policy for homogeneous quantum repeater chains. Unlike deterministic policies that require tracking link ages to maintain fidelity, the probabilistic approach forgoes strict fidelity control for simplified management. The research evaluates its performance against deterministic cutoffs across end-to-end rate, fidelity, and secret-key rate, identifying scenarios where the probabilistic method offers comparable or superior performance, especially for chains with fewer nodes or higher elementary link generation probabilities.
quantum-computingquantum-communicationquantum-repeatersquantum-information-theoryquantum-networks
“Deterministic cutoff policies improve end-to-end fidelity in quantum repeater chains by discarding links exceeding a cutoff age.”
paper / stephaniewehner / Feb 4
This paper investigates the minimal hardware improvements necessary to achieve intercity quantum teleportation with a fidelity of 2/3, the classical limit. The authors formulate hardware requirements as optimization problems, deriving analytical expressions for teleportation fidelity and rate based on a simplified noise model and heterogeneous quantum hardware. These analytical results, validated by NetSquid simulations, facilitate efficient exploration of optimization parameters, showing that while metropolitan quantum teleportation is achievable with current technology, intercity teleportation requires further, plausible hardware enhancements.
quantum-teleportationquantum-networksquantum-hardwarequantum-repeatersnetwork-topologysimulation
“Intercity quantum teleportation requires hardware improvements beyond the current state-of-the-art to reach a 2/3 fidelity.”
paper / stephaniewehner / Feb 4
Shared quantum entanglement enables Pareto-superior coordination in distributed two-server systems by providing non-local correlations that bypass communication latency. This advantage is specifically realized in dual-work optimization problems where the baseline throughput function is strictly convex, allowing for superior trade-offs between task throughput and request latency compared to classical communication-free limits.
quantum-computingdistributed-systemsnetwork-optimizationqueueing-theoryentanglementscientific-research
“Entanglement-assisted routing outperforms optimal communication-free classical strategies in dual-work optimization.”
paper / stephaniewehner / Nov 20
The realization of quantum networks capable of executing quantum applications necessitates robust control architectures. This paper highlights open questions and challenges identified during the evaluation of a modular control architecture for a generate-when-request type quantum network. The findings suggest that these challenges are not exclusive to the proposed architecture but are fundamental to the design of any quantum network control system, indicating a need for new protocols or adaptations of existing ones.
quantum-networksquantum-computingnetwork-architecturedistributed-systemscomputer-science-research
“Quantum networks aim to enable end-to-end entangled links for quantum network applications.”