Quantum Internet

Quantum Internet, Quantum Research

Quantum Teleportation: Paving the Way for a Quantum Internet


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Last week’s big quantum news centred on two proof of concept studies, both of which claim to have achieved quantum teleportation using a tripartite unit of quantum information called a qutrit, for the first time. While quantum teleportation has been demonstrated previously, it has only been carried out with qubits, which are capable of storing less information than qutrits but thought to be more stable. The novel feat was achieved independently by two teams, one led by Chinese physicist Guang-Can Guo at the University of Science and Technology of China (USTC) and the other, an international collaboration headed by Anton Zeilinger of the Austrian Academy of Sciences and Jian-Wei Pan of USTC. While both teams have reported their results in preprint articles, the article by the Austrian-led team has been accepted for publication in Physical Review Letters.

Competition for credit of this achievement aside, the team’s findings ultimately support each other in substantiating an advancement in quantum teleportation theory: namely, that quantum networks should be capable of carrying far more information with less interference than previously thought. This advancement—like many in the world of quantum—is likely to be found most exciting for physicists, evading the grasp of an applied significance for those of us with less scientific minds. Nevertheless, the notion of quantum teleportation has once again grabbed headlines and imaginations, providing a good opportunity to explore the concept and the applied significance that advancements like this might eventually have on our world.

While it may sound flash, quantum teleportation is an affair less akin to science fiction than one might imagine. On a basic level, quantum teleportation differs from ‘Star Trek teleportation’ because it is used to transmit information rather than macroscale physical objects, like human beings. This is possible because of quantum entanglement, a phenomenon of quantum physics that allows us to look at one particle or group of particles and know things about another, even if those particles are separated by vast distances. Quantum teleportation relies on entanglement to transfer information based on this shared state of being demonstrated by entangled particles. As such, quantum teleportation can be defined as “the instantaneous transfer of a state between particles separated by a long distance”.

Quantum teleportation holds the most obvious promise in the discipline of quantum communication, where its impact in secure communication was established as early as 1997. In 2017, Chinese scientists working with a team in Austria made waves with their announcement that they had achieved transnational quantum teleportation, establishing a quantum-secure connection for a video conference between the Chinese Academy of Sciences in Beijing and the Austrian Academy of Sciences in Vienna, some 7,600 kilometres away from each other. The experiment utilized China’s Micius satellite to transmit information securely using photons. Micius is a highly sensitive photon receiver, capable of detecting the quantum states of single photons fired from the ground. These photons, beamed via Micius, acted as qubits, allowing researchers in both countries to access a shared quantum key and thus enabling them to participate in the quantum-encrypted video call. Critically, should the data have been accessed by a third party, the code would be scrambled, leaving evidence of tampering for researchers at both ends of the connection.

This experiment, facilitated by quantum teleportation, proved two fundamental and impactful theories in quantum physics: that quantum communication can provide a previously unfathomable level of security and that it is capable of doing so on a global scale. Given these capabilities and coupled with the new qutrit proof-of-concept work, the realm of applied possibilities for quantum teleportation is expanding.

Aside from ultra-secure, transcontinental video conferences, one very hyped application for quantum teleportation is in the development of a hyper-fast quantum internet. Due to the entangled state of particles, information is transmitted instantaneously in quantum teleportation—faster than the speed of light. However, the transfer of this information is still required to operate within the current confines of classical communication. As such, even quantum information must travel through ground-based fibre optic cables or via photon-sensitive space-based satellites, like China’s Micius. This infrastructure is both expensive and potentially expansive, posing a formidable challenge for a global roll-out of a quantum internet. Still, these early experiments have laid the groundwork for the development of a quantum-secure Wi-Fi by putting theory to the test and producing promising results.

Currently, a team of researchers at Delft University in the Netherlands is working to build a quantum network, using quantum teleportation as the mode of transport for information between linkage points. The project, which aims to connect four cities in the Netherlands, is scheduled for completion in 2020. In China too, researchers are constructing the backbone for a quantum network to connect Beijing and Shanghai. Aside from the support of private corporations such as banks and other commercial entities, progress on the concept of both localised and international quantum networks has been spurned by pressing anxiety about global levels of cybersecurity

A critical advantage to a future quantum internet is the enhanced security afforded by quantum teleportation—the ability to create an unhackable connection. This could have serious implications for national security and could present a potential solution for many foreign surveillance and interference challenges that countries face today. For example, it is now public knowledge in the U.S. that Russia has the demonstrative ability to directly interfere with most paperless voting systems. While states are currently reticent about making changes to the current U.S. vote-casting system, alternatives are slowly being considered—from regressive paper ballot casting to progressive blockchain applications—in order to safeguard American votes against hacking efforts. Quantum teleportation could offer an interesting alternative in this space as the technology continues to develop.

Though quantum teleportation will not be transporting human beings between planets any time soon, it will play a key role in ushering in an internet revolution. While it remains to be seen exactly how that revolution will play out, it is clear that it will bring an unprecedented level of security and speed to global communications. It is also apparent that the level of interest in the secure and high-speed communications afforded through quantum teleportation is broad and deep, spanning both public and private sectors across the globe. Quantum teleportation has recently seen a number of experimental proofs, pushing the field of quantum communications to the fore of quantum development and promising to deliver a much sought-after security transformation within the decade.

Quantum Internet

The Road to a Quantum Internet


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Google Server Farm credit Google

What will a quantum network look like? How will it integrate with the current internet? Image Credit: Google

Alexander Vipond

A research team at the University of Delft in the Netherlands has laid out a roadmap for a quantum internet. Led by Stephanie Wehner, David Elkouss and Ronald Hanson, the trio have set out what is necessary to establish a quantum internet, how it will interact with the current internet, and where it could take us.

The researchers say a quantum internet is not designed to replace the current internet but complement it by offering various advantages.

These include much more secure remote access to the cloud, stronger security identification methods, secure messaging and more accurate time synchronization across devices. The capabilities of a quantum internet would grow as it develops through six stages (see the graphic below). A quantum internet is also capable of developing in parallel to quantum computers which are only necessary to reach its final stage.

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The proposed levels to a full-fledged quantum internet. Image credit: Elkouss et al in Science, Vol. 362, Issue 6412.

The first stage in the process is to build a fast and reliable small network of nodes that can transmit and receive quantum entangled messages. This requires a physical channel to send the message such as a fiber optic cable, a quantum repeater capable of extending the distance information can be sent, and end nodes to receive the messages.

The Delft group is building such a network between four cities in the Netherlands and hopes to replicate the achievements of the ARPANET (the precursor to the modern internet) by sending the first message between Delft University and Amsterdam in 2020. Countries such as China have also been building first stage quantum networks such as the Beijing-Shanghai quantum link for security purposes.

In a world in which the privacy and security of the internet are rapidly eroding in the face of surveillance capitalism, aggressive state espionage, new technological challenges (such as AI and the Internet of Things) and economic incentivisation for speed over security, could a quantum internet act as a partial cure to such dire strategic trends?

The short answer is yes. By using near faultless quantum encryption there is an opportunity for small networks to regain the confidentiality and integrity of their information. The recent use of internet traffic rerouting and cloud hopping to conduct industrial espionage against Western countries including Australia and the United States could be mitigated by quantum secure remote access protocols and the use of quantum internets.

In the final stage of a quantum internet, the creation of quantum byzantine agreements could also help decentralised networks organise and share information safely even when there is a malicious actor hiding amongst them. This is because the arrangement of the system is resilient enough to accommodate up to a third of the actors in the system being bad whilst simultaneously allowing good actors verify their information and carry out their message.

The long answer is that this is a partial technical solution to two human problems. One, the age-old security problem of states stealing and sponsoring proxies to acquire knowledge from competitors. Using a quantum internet will raise the cost for attackers but it will not deter them as the geo-strategic or business imperatives (or a civil-military fusion of the two) for compromising communications will continue to drive their actions. If the stages of a quantum internet can grant increasingly absolute communications security, as it has been theorised to do, what is of a higher likelihood is that it will simply shift attackers’ attention to the humans on either end of the node.

Two, the new-age problem of structural deficiencies in internet security created by digital business models that require huge amounts of data and whose speed of technology iteration undermines the security of the flow of new technologies and infrastructure that fuel the internet’s expansion. The complexity of this problem cannot be answered by one technology and requires multiple solutions to be sought across government and industry.

In the darkness of the web there stands a path of light. The photons that entangle a quantum message, whilst not a silver bullet to problems of cybersecurity, can provide a much greater level of security than what we have now. The scientific and engineering challenges along the six stages will be difficult to surmount. However, by offering a unified approach across industries with a common plan, the Delft team have brought the possibility of a quantum internet several steps closer to being a new part of the web.

For a more in depth look at the future of a quantum internet, you can view Project Q’s interview with Stephanie Wehner here.