US-12627910-B2 - Multiplexed telecommunication-band quantum networking with atom arrays in optical cavities

Abstract

The disclosure includes a multiplexed telecommunication-band quantum network that utilizes atomic arrays in optical cavities. An example quantum networking system includes at least one quantum repeater node. The quantum repeater node includes an array of neutral atoms disposed in an optical cavity and a fiber-optic switch (FOS). The FOS is optically coupled to the optical cavity. The quantum repeater node also includes at least one beamsplitter. The at least one beamsplitter is optically coupled to the FOS.

Inventors

• Jacob Paul COVEY
• William Chiu Wong HUIE
• Jia Pern Neville CHEN
• Lintao Li
• Hannes Bernien
• Shankar GIRIJAVALLABHAN MENON

Assignees

• THE BOARD OF TRUSTEES OF THE UNIVERSITY OF ILLINOIS
• THE UNIVERSITY OF CHICAGO

Dates

Publication Date

20260512

Application Date

20230707

Claims (18)

1. 1 . A quantum networking system comprising: at least one quantum repeater node, wherein the quantum repeater node comprises: an array of neutral atoms disposed in an optical cavity, wherein the array of neutral atoms is formed by using one or more optical tweezers; a fiber-optic switch (FOS), wherein the FOS is optically coupled to the optical cavity; and at least one beamsplitter, wherein the at least one beamsplitter is optically coupled to the FOS.
2. 2 . The system of claim 1 , wherein the quantum repeater node is configured to perform multiplexed entanglement generation.
3. 3 . The system of claim 1 , wherein the quantum repeater node is configured to operate within a telecommunication wavelength band between 1260 nm and 1675 nm.
4. 4 . The system of claim 1 , wherein the array of neutral atoms comprises a plurality of neutral ytterbium ( 171 Yb) atoms.
5. 5 . The system of claim 1 , wherein the array of neutral atoms comprises a linear arrangement of neutral atoms with an array length of between 100 microns and 300 microns.
6. 6 . The system of claim 1 , wherein the array of neutral atoms comprises a linear array of between 5 and 500 neutral atoms.
7. 7 . The system of claim 1 , wherein at least a portion of the neutral atoms of the array of neutral atoms are configured to perform Rydberg entangling operations.
8. 8 . The system of claim 1 , wherein the optical cavity comprises a pair of near-concentric mirrors.
9. 9 . The system of claim 8 , wherein the near-concentric mirrors are spherically symmetric.
10. 10 . The system of claim 8 , wherein the pair of near-concentric mirrors are separated by a mirror spacing of between 0.25 cm and 2.0 cm.
11. 11 . The system of claim 1 , wherein the system further comprises a photon detector (PD) that is optically coupled to the optical cavity via the beamsplitter, wherein the PD is configured to provide information indicative of which atoms at each of the quantum repeater nodes are in a Bell state.
12. 12 . The system of claim 1 , wherein the system further comprises a further quantum repeater node, wherein the further quantum repeater node comprises: a further array of neutral atoms disposed in a further optical cavity; and a further FOS, wherein the further FOS is optically coupled to the at least one beamsplitter, wherein the further array of neutral atoms is configured to generate a quantum entangled Bell pair with respect to the array of neutral atoms.
13. 13 . The system of claim 12 , wherein the system provides a distributed, fault-tolerant, quantum computer.
14. 14 . The system of claim 12 , wherein a Bell pair comprises a two-qubit quantum state.
15. 15 . The system of claim 12 , wherein the system is configured to provide 25 or more Bell pairs.
16. 16 . The system of claim 15 , wherein the Bell pairs undergo an entanglement purification process to produce Bell pairs with higher fidelity.
17. 17 . The system of claim 12 , wherein the system further comprises a further PD, wherein the further PD is optically coupled to the at least one beamsplitter, wherein the further PD is configured to provide information indicative of which atoms in the further array of neutral atoms are in a Bell state.
18. 18 . A quantum networking method comprising: providing a first array of neutral atoms in a first quantum repeater node; providing a second array of neutral atoms in a second quantum repeater node, wherein providing the first array of neutral atoms and providing the second array of neutral atoms is performed by way of one or more optical tweezers; performing atom-photon entanglement of at least one neutral atom of the first array of neutral atoms via a four-wave mixing process so as to form a plurality of atom-photon Bell pairs; distributing entangled Bell pairs between the first quantum repeater node and the second quantum repeater node; and performing an entanglement purification processes on two or more Bell pairs to produce at least one new Bell pair with higher fidelity.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to and incorporates by reference the content of U.S. Provisional Pat. App. No. 63/359,699, filed Jul. 8, 2022. GOVERNMENT LICENSE RIGHTS This invention was made with government support under 2112663, 2137642 and 2016136 awarded by the National Science Foundation. The government has certain rights in the invention. BACKGROUND Despite recent work establishing neutral atom-based nodes for quantum communication networks, a major bottleneck for the development of such networks is the exponential attenuation and long transit time associated with sending single photons—the quantum bus that distributes entanglement—over long physical distances. Since the success probability per entanglement generation attempt is low and success must be “heralded” via two-way communication, there is intense interest in developing architectures that can “multiplex” many signals in parallel on each attempt. Multiplexing is necessary to construct networks much larger than the attenuation length in optical fiber (approximately 20 km in the telecommunication-band), but it is not sufficient. Intermediate “repeater” nodes are required to swap the entanglement and teleport quantum information. Additionally, entanglement “purification” protocols are often needed to improve the fidelity of the distributed quantum states. Accordingly, there is a need for improved systems and methods that enable more reliable, longer-distance quantum communications and networking. SUMMARY Embodiments of the present disclosure include systems and methods for interfacing quantum processors comprising neutral atom arrays with telecommunication-band photons in a multiplexed network architecture. In certain embodiments, the use of a large atom array instead of a single atom mitigates the deleterious effects of two-way communication and improves the entanglement rate between two nodes by nearly two orders of magnitude. Certain embodiments simultaneously provide the ability to perform high-fidelity deterministic gates and readout within each node, opening the door to quantum repeater and purification protocols to enhance the length and fidelity of the network, respectively. In some embodiments, the use of intermediate nodes as quantum repeaters demonstrates the feasibility of entanglement distribution over approximately 1500 km based on realistic assumptions, providing a blueprint for a transcontinental network. Various embodiments include a platform, systems and methods that can distribute roughly 35 Bell pairs over metropolitan distances, which could serve as the backbone of a distributed fault-tolerant quantum computer. Exemplary implementations and embodiments include long-distance quantum networking, quantum key distribution, fault-tolerant distributed quantum computing (metropolitan scale), an optical atomic clock network, and modular quantum computing architectures. In a first aspect, a quantum networking system is provided. The system includes at least one quantum repeater node. The quantum repeater node includes an array of neutral atoms disposed in an optical cavity. The quantum repeater node also includes a fiber-optic switch (FOS). The FOS is optically coupled to the optical cavity. The system also includes at least one beamsplitter that is optically coupled to the FOS. In a second aspect, a quantum networking method is provided. The method includes providing a first array of neutral atoms in a first quantum repeater node and providing a second array of neutral atoms in a second quantum repeater node. The method also includes performing atom-photon entanglement of at least one neutral atom of the first array of neutral atoms via a four-wave mixing process so as to form a plurality of atom-photon Bell pairs. The method additionally includes distributing entangled Bell pairs between the first quantum repeater node and the second quantum repeater node. The method yet further includes performing an entanglement purification processes on two or more Bell pairs to produce at least one new Bell pair with higher fidelity. These as well as other aspects, advantages, and alternatives will become apparent to those of ordinary skill in the art by reading the following detailed description with reference where appropriate to the accompanying drawings. Further, it should be understood that the description provided in this summary section and elsewhere in this document is intended to illustrate the claimed subject matter by way of example and not by way of limitation. BRIEF DESCRIPTION OF THE FIGURES FIG. 1A illustrates an overview of the quantum network architecture, according to an example embodiment. FIG. 1B illustrates an overview of the quantum network architecture, according to an example embodiment. FIG. 1C illustrates an overview of the quantum network architecture, according to an example embodiment. FIG. 1D illustrates an overview of the quantum network architecture, according to an example