Entanglement routing in quantum data networks plays a vital role to support various quantum applications. Existing works on entanglement routing either ignored the Entangled Photon Source (EPS) placement issue or simply assumed a pool of EPSes at a centralized location that can provision entanglement over arbitrary quantum links. In this paper, we propose LightER to solve the joint EPS placement and entanglement routing problem based on the assumption that EPSes are distributed over a quantum network, where an EPS, which is co-located with a quantum node, can send one entangled photon at a time to one of the adjacent nodes only. The salient features of LightER include (i) LightER uses a demand-agnostic EPS placement scheme to maximize network throughput and fairness for all feasible entanglement connection (EC) establishment demands, and (ii) most of the requested ECs can be established over their corresponding Entanglement Paths (EPs) determined offline, and only a small percentage of the ECs will be established over EPs that need to be calculated online, resulting in fast and efficient entanglement routing. Extensive simulations show that compared with schemes without proper EPS placement or entanglement routing, LightER can improve the network throughput by up to 215% and 56.2%, respectively.Entanglement routing in quantum data networks plays a vital role to support various quantum applications. Existing works on entanglement routing either ignored the Entangled Photon Source (EPS) placement issue or simply assumed a pool of EPSes at a centralized location that can provision entanglement over arbitrary quantum links. In this paper, we propose LightER to solve the joint EPS placement and entanglement routing problem based on the assumption that EPSes are distributed over a quantum network, where an EPS, which is co-located with a quantum node, can send one entangled photon at a time to one of the adjacent nodes only. The salient features of LightER include (i) LightER uses a demand-agnostic EPS placement scheme to maximize network throughput and fairness for all feasible entanglement connection (EC) establishment demands, and (ii) most of the requested ECs can be established over their corresponding Entanglement Paths (EPs) determined offline, and only a small percentage of the ECs will be established over EPs that need to be calculated online, resulting in fast and efficient entanglement routing. Extensive simulations show that compared with schemes without proper EPS placement or entanglement routing, LightER can improve the network throughput by up to 215% and 56.2%, respectively.

IEEE International Conference on Distributed Computing Systems (ICDCS)Jul 23, 20246 citations

Optimizing Entanglement Distribution and Quantum Source Placement in Probabilistic Quantum Networks

S. N. Singh, Adhishek Kr. Mishra, Rajesh Singh

IEEE International Conference on Computing, Power and Communication Technologies (IC2PCT)May 15, 20260 citations

Distributed Entanglement Distribution Using Multiple Entanglement Sources in WDM-based Quantum Optical Networks

Anuj Agrawal, Abhay Singh Dulta, Bhaskar Kanseri

Quantum network implementations using single spontaneous parametric downconversion (SPDC)-based broadband entangled photon pair source (EPPS) have been reported recently. Here, leveraging the wavelength-correlation between entangled photon pairs, the traditional wavelength division multiplexing (WDM) method is utilized to route photons based on their wavelengths. From single EPPS, entangled photon pairs are distributed in a centralized way to different node pairs in the network. However, the number of nodes pairs that can be entangled in a network is limited by the number of entangled wavelength pairs that an EPPS can generate. To entangle a higher number of node pairs in a network, multiple EPPSs can be employed. In this work, we present a WDM-based entanglement distribution approach using multiple EPPSs in multi-hop repeaterless mesh optical networks. We experimentally characterize two EPPSs developed in-house and consider multiple such EPPSs in the network to perform network-level simulations. We consider heterogeneous entanglement demands requiring different entanglement bit (ebit) rates and entanglement visibility. For each entanglement demand, EPPS placement/selection, wavelength-pair assignment, and photon pair routing are performed considering the degradation in both ebit rate and visibility with fiber length and hops in the network. Two main findings of this study include: (i) a hybrid approach of one-photon (OP) and both-photon (BP) entanglement distribution provides higher flexibility in multi-EPPS placement and (ii) distributed entanglement distribution using multiple EPPSs enables better entanglement resource utilization and higher entanglement demand acceptance as compared to centralized entanglement distribution.Quantum network implementations using single spontaneous parametric downconversion (SPDC)-based broadband entangled photon pair source (EPPS) have been reported recently. Here, leveraging the wavelength-correlation between entangled photon pairs, the traditional wavelength division multiplexing (WDM) method is utilized to route photons based on their wavelengths. From single EPPS, entangled photon pairs are distributed in a centralized way to different node pairs in the network. However, the number of nodes pairs that can be entangled in a network is limited by the number of entangled wavelength pairs that an EPPS can generate. To entangle a higher number of node pairs in a network, multiple EPPSs can be employed. In this work, we present a WDM-based entanglement distribution approach using multiple EPPSs in multi-hop repeaterless mesh optical networks. We experimentally characterize two EPPSs developed in-house and consider multiple such EPPSs in the network to perform network-level simulations. We consider heterogeneous entanglement demands requiring different entanglement bit (ebit) rates and entanglement visibility. For each entanglement demand, EPPS placement/selection, wavelength-pair assignment, and photon pair routing are performed considering the degradation in both ebit rate and visibility with fiber length and hops in the network. Two main findings of this study include: (i) a hybrid approach of one-photon (OP) and both-photon (BP) entanglement distribution provides higher flexibility in multi-EPPS placement and (ii) distributed entanglement distribution using multiple EPPSs enables better entanglement resource utilization and higher entanglement demand acceptance as compared to centralized entanglement distribution.

quant-pharXiv:2607.19849Jul 23, 20260 citations

Optimal Switching Networks for Paired-Egress Bell State Analyzer Pools

Marii Koyama, Claire Yun, Amin Taherkhani +5 more

To scale quantum computers to useful levels, we must build networks of quantum computational nodes that can share entanglement for use in distributed forms of quantum algorithms. In one proposed architecture, node-to-node entanglement is created when nodes emit photons entangled with stationary memories, with the photons routed through a switched interconnect to a shared pool of Bell state analyzers (BSAs). Designs that optimize switching circuits will reduce loss and crosstalk, raising entanglement rates and fidelity. We present optimal designs for switched interconnects constrained to planar layouts, appropriate for silicon waveguides and Mach-Zehnder interferometer (MZI) $2\times 2$ switch points. The architectures for the optimal designs are scalable and algorithmically structured to pair any arbitrary inputs in a rearrangeable, non-blocking way. For pairing $N$ inputs, $N(N-2)/4$ switches are required, which is less than half of number of switches required for full permutation switching networks. An efficient routing algorithm is also presented for each architecture. These designs can also be employed in reverse for entanglement generation using a shared pool of entangled paired photon sources.To scale quantum computers to useful levels, we must build networks of quantum computational nodes that can share entanglement for use in distributed forms of quantum algorithms. In one proposed architecture, node-to-node entanglement is created when nodes emit photons entangled with stationary memories, with the photons routed through a switched interconnect to a shared pool of Bell state analyzers (BSAs). Designs that optimize switching circuits will reduce loss and crosstalk, raising entanglement rates and fidelity. We present optimal designs for switched interconnects constrained to planar layouts, appropriate for silicon waveguides and Mach-Zehnder interferometer (MZI)$2\times 2$switch points. The architectures for the optimal designs are scalable and algorithmically structured to pair any arbitrary inputs in a rearrangeable, non-blocking way. For pairing$N$inputs,$N(N-2)/4$switches are required, which is less than half of number of switches required for full permutation switching networks. An efficient routing algorithm is also presented for each architecture. These designs can also be employed in reverse for entanglement generation using a shared pool of entangled paired photon sources.

arXiv:2405.09860IEEE International Conference on Quantum Computing and Engineering (QCE)Sep 15, 20245 citations

Entanglement distribution in quantum communication and beyond

IEEE/LEOS Summer Topical MeetingsJul 1, 20110 citations

2\times 2

switch points. The architectures for the optimal designs are scalable and algorithmically structured to pair any arbitrary inputs in a rearrangeable, non-blocking way. For pairing

N

inputs,

N(N-2)/4

switches are required, which is less than half of number of switches required for full permutation switching networks. An efficient routing algorithm is also presented for each architecture. These designs can also be employed in reverse for entanglement generation using a shared pool of entangled paired photon sources.