The quantum internet will give us an infrastructure able to distribute and process quantum information on a planetary scale. The core of that internet will be formed from quantum error corrected links able to distribute information over large distances all while maintaining their coherence for long periods of time. However, many of the applications at the edge of such networks may rely on raw unencoded data – not protected by error correcting codes due to the nature of how it was generated. In this presentation, we will describe an experiment in which quantum information encoded on a physical qubit can be teleported into an error-corrected logical qubit. Our demonstration shows how one can get information into and out of quantum processors and tomorrows large-scale quantum networks.
The quantum internet will give us an infrastructure able to distribute and process quantum information on a planetary scale. The core of that internet will be formed from quantum error corrected links able to distribute information over large distances all while maintaining their coherence for long periods of time. However, many of the applications at the edge of such networks may rely on raw unencoded data – not protected by error correcting codes due to the nature of how it was generated. In this presentation, we will describe an experiment in which quantum information encoded on a physical qubit can be teleported into an error-corrected logical qubit. Our demonstration shows how one can get information into and out of quantum processors and tomorrows large-scale quantum networks.
Quantum networks play a pivotal role in quantum information science, which not only provide a secure communication platform for remote access to quantum computers but also serve as the strategic core for achieving large-scale quantum information processing, forming the foundational infrastructure for the future global-scale quantum internet. Quantum teleportation, which enables the transmission of unknown quantum states over long distances by employing quantum entanglement together with classical communication, is essential for the distribution of quantum resources in the construction of the global-scale quantum internet. To realize a global-scale quantum internet, quantum repeater protocols represent one of the most promising approaches for enabling quantum communication between any nodes. This concise review presents representative experimental demonstrations of quantum teleportation for constructing quantum networks across different physical platforms. Along this trajectory, the review discusses current challenges, open issues, and future perspectives toward scalable and practical quantum internet.
Quantum error correction is an essential tool for reliably performing tasks for processing quantum information on a large scale. However, integration into quantum circuits to achieve these tasks is problematic when one realizes that nontransverse operations, which are essential for universal quantum computation, lead to the spread of errors. Quantum gate teleportation has been proposed as an elegant solution for this. Here, one replaces these fragile, nontransverse inline gates with the generation of specific, highly entangled offline resource states that can be teleported into the circuit to implement the nontransverse gate. As the first important step, we create a maximally entangled state between a physical and an error-correctable logical qubit and use it as a teleportation resource. We then demonstrate the teleportation of quantum information encoded on the physical qubit into the error-corrected logical qubit with fidelities up to 0.786. Our scheme can be designed to be fully fault tolerant so that it can be used in future large-scale quantum technologies.
Quantum communication which is our ability to transmission quantum information between remote locations is a primitive operation necessary for a future quantum internet. Quantum communication at its heart relies on establishing entangled links between remote locations which can then be used to teleport quantum data. Typically channel losses limit the distance that photons can be sent without some form of quantum repeater networks which segments the channel into smaller pieces. Entanglement distribution, purification and swapping operations then allows one to create high fidelity entangled pairs between the desired remote locations. Several generations of quantum repeaters have been proposed with dramatically increasing performance but the ultimate network performance is limited by channel losses which are typically fundamental in nature. Here we introduce the concept of quantum multiplexing, which allows us to both minimize the number of photons needed in the entanglement distribution processing but also enhance the quality of the entangled pairs generated. In this presentation we discuss the potential performance gains our quantum multiplexing approach gives.
In quantum networks an important goal is to reduce resource requirements for the transport and communication of quantum information. Quantum network coding presents a way to do this by distributing entangled states over a network that would ordinarily exhibit contention. In this work, we study measurement-based quantum network coding (MQNC), which is a protocol particularly suitable for noisy intermediate-scale quantum devices. In particular, we develop techniques to adapt MQNC to state-of-the-art superconducting processors and subsequently demonstrate successful teleportation of quantum information, giving new insight into MQNC in this context after a previous study was not able to produce a useful degree of entanglement. The teleportation in our demonstration is shown to occur with fidelity higher than could be achieved via classical means, made possible by considering qubits from a polar cap of the Bloch sphere. We also present a generalization of MQNC with a simple mapping onto the heavy-hex processor layout and a direct mapping onto a proposed logical error-corrected layout. Our work provides some useful techniques to test and successfully carry out quantum network coding.
Quantum teleportation is a technique for transferring quantum information from a sender at one location to a receiver some distance away. While teleportation is commonly portrayed in science fiction as a means to transfer physical objects from one location to the next, quantum teleportation only transfers quantum information. In July, the US Department of Energy unveiled a blueprint for the first quantum internet, connecting several of its National Laboratories across the country. A quantum internet would be able to transmit large volumes of data across immense distances at a rate that exceeds the speed of light. Traditional computer data is coded in either zeros or ones. Quantum information is superimposed in both zeros and ones simultaneously. Academics, researchers and IT professionals will need to create devices for the infrastructure of quantum internet including: quantum routers, repeaters, gateways, hubs, and other quantum tools.
The coming Quantum Internet will bring us new capabilities: advanced cryptographic functions, high-precision sensor networks for uses such as high-resolution astronomy, and secure distributed quantum computing. Experimental progress on the components for quantum repeaters is moving at a dizzying rate, and theorists have proposed various approaches to managing errors to create high-fidelity quantum entanglement. Building quantum networks presents different challenges from building quantum links. I will give an overview of these issues, then discuss the even more daunting challenge of creating a network of networks -- an internetwork -- and show how our simulations are guiding the design of a true quantum Internet. These challenges include routing (path selection), resource management such as multiplexing techniques, and security considerations within individual networks. Recently, we have discovered that it is possible for a single hijacked quantum repeater to frame other repeaters as malicious, substantially disrupting network operations. All of these issues are magnified when discussing autonomous networks that exchange information, known as an internetwork. In internetworking, not only is the scale of the problem daunting, but heterogeneous technologies will be deployed and demand interoperability at the logical level as well as the physical. Network operators also prefer to maintain the privacy of their own network operations, requiring mechanisms including connection establishment to operate with minimal sharing of information across network boundaries.