Optimal entanglement swapping in quantum repeaters

• URL: http://arxiv.org/abs/2109.00793v1
• Date: Thu, 2 Sep 2021 09:02:40 GMT
• Title: Optimal entanglement swapping in quantum repeaters
• Authors: Evgeny Shchukin, Peter van Loock
• Abstract summary: We formulate the problem of finding the optimal entanglement swapping scheme in a quantum repeater chain as a Markov decision process. We show that the commonly used "doubling" scheme does not always produce the best possible raw rate. Our approach provides the minimal possible waiting time of quantum repeaters in a fairly general physical setting.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: We formulate the problem of finding the optimal entanglement swapping scheme in a quantum repeater chain as a Markov decision process and present its solution for different repeater's sizes. Based on this, we are able to demonstrate that the commonly used "doubling" scheme for performing probabilistic entanglement swapping of probabilistically distributed entangled qubit pairs in quantum repeaters does not always produce the best possible raw rate. Focussing on this figure of merit, without considering additional probabilistic elements for error suppression such as entanglement distillation on higher "nesting levels", our approach reveals that a power-of-two number of segments has no privileged position in quantum repeater theory; the best scheme can be constructed for any number of segments. Moreover, classical communication can be included into our scheme, and we show how this influences the raw waiting time for different number of segments, confirming again the optimality of "non-doubling" in some relevant parameter regimes. Thus, our approach provides the minimal possible waiting time of quantum repeaters in a fairly general physical setting.

Related papers

• Generalized quantum repeater graph states [1.7635061227370266]
  We present a new approach to ensure the loss tolerance of distributing a single ebit. We demonstrate that our new scheme significantly outperforms the previous work with much flexibility. These findings offer new insights into the scalability and reliability of loss-tolerant quantum networks.
  arXiv  Detail & Related papers  (2024-07-01T16:21:37Z)
• Entanglement Distribution in Quantum Repeater with Purification and Optimized Buffer Time [53.56179714852967]
  We explore entanglement distribution using quantum repeaters with optimized buffer time. We observe that increasing the number of memories on end nodes leads to a higher entanglement distribution rate per memory. When imperfect operations are considered, however, we make the surprising observation that the per-memory entanglement rate decreases with increasing number of memories.
  arXiv  Detail & Related papers  (2023-05-23T23:23:34Z)
• Suppressing Amplitude Damping in Trapped Ions: Discrete Weak Measurements for a Non-unitary Probabilistic Noise Filter [62.997667081978825]
  We introduce a low-overhead protocol to reverse this degradation. We present two trapped-ion schemes for the implementation of a non-unitary probabilistic filter against amplitude damping noise. This filter can be understood as a protocol for single-copy quasi-distillation.
  arXiv  Detail & Related papers  (2022-09-06T18:18:41Z)
• Exact rate analysis for quantum repeaters with imperfect memories and entanglement swapping as soon as possible [0.0]
  We present an exact rate analysis for a secret key that can be shared among two parties employing a linear quantum repeater chain. We consider additional tools and parameters such as memory cut-offs, multiplexing, initial state and swapping gate fidelities.
  arXiv  Detail & Related papers  (2022-03-19T12:55:56Z)
• Rate limits in quantum networks with lossy repeaters [0.6299766708197883]
  We quantify how the presence of loss in repeater stations affect the maximum attainable rates for quantum communication. In the linear chain scenario we show that, by increasing the number of repeater stations, the maximum rate cannot overcome a quantity which solely depends on the loss of a single station.
  arXiv  Detail & Related papers  (2021-10-19T18:00:01Z)
• Cluster-Promoting Quantization with Bit-Drop for Minimizing Network Quantization Loss [61.26793005355441]
  Cluster-Promoting Quantization (CPQ) finds the optimal quantization grids for neural networks. DropBits is a new bit-drop technique that revises the standard dropout regularization to randomly drop bits instead of neurons. We experimentally validate our method on various benchmark datasets and network architectures.
  arXiv  Detail & Related papers  (2021-09-05T15:15:07Z)
• Realization of arbitrary doubly-controlled quantum phase gates [62.997667081978825]
  We introduce a high-fidelity gate set inspired by a proposal for near-term quantum advantage in optimization problems. By orchestrating coherent, multi-level control over three transmon qutrits, we synthesize a family of deterministic, continuous-angle quantum phase gates acting in the natural three-qubit computational basis.
  arXiv  Detail & Related papers  (2021-08-03T17:49:09Z)
• Quantum Error Mitigation Relying on Permutation Filtering [84.66087478797475]
  We propose a general framework termed as permutation filters, which includes the existing permutation-based methods as special cases. We show that the proposed filter design algorithm always converges to the global optimum, and that the optimal filters can provide substantial improvements over the existing permutation-based methods.
  arXiv  Detail & Related papers  (2021-07-03T16:07:30Z)
• Overcoming the repeaterless bound in continuous-variable quantum communication without quantum memories [0.0]
  One of the main problems in quantum communications is how to achieve high rates at long distances. We introduce a continuous-variable protocol which overcomes the repeaterless bound and scales like the single-repeater bound. We show that our scheme can be extended to longer repeater chains using quantum memories.
  arXiv  Detail & Related papers  (2021-05-08T04:02:17Z)
• Entanglement-assisted entanglement purification [62.997667081978825]
  We present a new class of entanglement-assisted entanglement purification protocols that can generate high-fidelity entanglement from noisy, finite-size ensembles. Our protocols can deal with arbitrary errors, but are best suited for few errors, and work particularly well for decay noise.
  arXiv  Detail & Related papers  (2020-11-13T19:00:05Z)
• Optimising repeater schemes for the quantum internet [0.0]
  We study three different experimental quantum repeater implementations on their ability to distribute entanglement. We use the algorithm to study three different experimental quantum repeater implementations on their ability to distribute entanglement.
  arXiv  Detail & Related papers  (2020-06-22T13:18:49Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.