Quantum State Transfer with Limited Resources

Lorena Ballesteros Ferraz

Jincheng Zhang

Quantum information transfer presents significant challenges due to the fragility of quantum states and the potential for decoherence. Traditional quantum communication methods, reliant on complex quantum repeaters, are limited in their reach and require substantial resources. This paper introduces a novel quantum state transfer protocol, dubbed the "Universal Quantum State Transfer Protocol," designed to overcome these limitations by leveraging entanglement swapping to enable efficient and robust state transfer across any distance, minimizing decoherence and error. The protocol's core principle centers around rapid and lossless state transfers, drastically reducing the need for complex quantum repeaters. This work explores the implementation of a unique entanglement swapping mechanism to achieve this goal, demonstrating its potential to revolutionize quantum communication. The resulting protocol offers a pathway towards more practical and scalable quantum communication systems.

M. Bertolotti, Fabio Antonio Bovino, Concita Sibilia

Keng Wah Choo, L. C. Kwek

We studied the use of quantum dots as a resource for teleportation and investigated how entanglement of the resource would affect the average fidelity of such a process. We then identified a suitable magnetic field, interdot distance, and the temperature to be used to achieve an average fidelity beyond the limit of the classical communication channel. We also explored the effects of decoherence on the teleportation process. We then investigated the state transfer or swapping between two quantum dots. We found that perfect quantum swap is possible in this system. A smaller magnetic field and interdot distance shortened the perfect state transfer time. Finally, we report on the performance of the system under different decoherence models.

Zeyu Kuang, Oliver Diekmann, Lorenz Fischer +2 more

High-fidelity state transfer is fundamentally limited by time-reversal symmetry: one qubit emits a photon with a certain temporal pulse shape, whereas a second qubit requires the time-reversed pulse shape to efficiently absorb this photon. This limit is often overcome by introducing active elements. Here, we propose an alternative solution: by tailoring the dispersion relation of a waveguide, the photon pulse emitted by one qubit is passively reshaped into its time-reversed counterpart, thus enabling perfect absorption. We analytically derive the optimal dispersion relations in the limit of small and large qubit-qubit separations, and numerically extend our results to arbitrary separations via multiparameter optimization. We further propose a spatially inhomogeneous waveguide that renders the state transfer robust to variations in qubit separations. In all cases, we obtain near-unity transfer fidelity (>= 98%) that is robust against imperfections in parameter values and propagation loss. Our dispersion-engineered waveguide provides a compact and passive route toward on-chip quantum networks, highlighting dispersion as a powerful resource in waveguide quantum electrodynamics.

Jincheng Zhang

Quantum state transfer is a critical process in quantum information processing, enabling the manipulation and transfer of quantum states between qubits. Current state transfer protocols often suffer from inefficiencies, requiring significant resources and time. This paper introduces a novel quantum state transfer protocol utilizing Adaptive Resonance Networks (ARNs) to optimize the transfer process, minimizing resource requirements and enhancing stability. We propose a dynamic adaptation of the ARN's weights, allowing for faster and more reliable state transfers. The core mechanism focuses on a feedback loop that continuously adjusts the network's parameters to achieve optimal transfer performance. This work presents a theoretical analysis and preliminary experimental validation demonstrating the effectiveness of this approach compared to existing state transfer techniques.