Quantum Teleportation Moves to Three Nodes
Dutch researchers teleport quantum information across rudimentary quantum network
While China is the leader in quantum teleportation and the quantum comms/internet, researchers elsewhere aren’t standing still.
Quantum computing is a National security priority for many countries. This is because they realize what the future of cybersecurity at the intersection of artificial intelligence becomes. The power of a future quantum Internet is based on the ability to send quantum information (quantum bits) between the nodes of the network. This will enable all kinds of applications such as securely sharing confidential information, linking several quantum computers together to increase their computing capability, and the use of highly precise, linked quantum sensors.
About a week ago it was announced researchers in Delft have succeeded in teleporting quantum information across a rudimentary network.
This first of its kind is an important step towards a future quantum internet. This breakthrough was made possible by a greatly improved quantum memory and enhanced quality of the quantum links between the three nodes of the network. The researchers, working at QuTech—a collaboration between Delft University of Technology and the Netherlands Organization for Applied Scientific Research (TNO)—are publishing their findings today in the scientific journal Nature.
Birth of the Quantum Internet
Researchers in the Netherlands have shown they can transmit quantum information via an intermediary node, a feature necessary to make the so-called quantum internet possible. I believe this has occurred in China already, but the Dutch researchers are still saying it’s a first.
You can see the video here.
In recent years, scientists have argued that the quantum internet presents a more desirable network for transferring secure data, in addition to being necessary when connecting multiple quantum systems. All of this has been attracting investment from the US government, among others.
The Quantum Internet may be a more secure and less easily influence by hostile foreign states. This is still an incredible milestone: Let’s try to let it sink in:
Physicists in the Netherlands have shown for the first time that quantum information can be reliably teleported between network nodes that are not directly connected to each other.
How far indeed we have come to arrive at “spooky action a distance” ourselves.
Scientists have improved their ability to send quantum information across distant computers — and have taken another step toward the network of the future. The NYT fails to point out what kind of a future that actually is.
Researchers at the Delft University of Technology with one of the three nodes in a quantum computing network, which uses mirrors, filters and lasers to guide electrons into a synthetic diamond.Credit...Marieke de Lorijn for QuTech.
The paper was published on May 25th, 2022 you can read it here.
Quantum computing is advancing in both tiny and giant steps. Some think Quantum computing opens up a world of infinite possibilities. If the Metaverse is about virtualization, and Web3 is about decentralization, Quantum computing might enable us to talk to our colony on Mars one day on a shared Quantum internet.
The hype is real for Quantum computing as some analysts are saying the magic, that we might be harnessing the mysterious powers of quantum mechanics, the technology could perform tasks in minutes that even supercomputers could not complete in thousands of years. While that remains to be seen, it is exciting.
Towards a Scalable Quantum Internet
According to the researchers, who created the world’s first three-node quantum network at QuTech (a collaboration between the Delft University of Technology and TNO) in 2021, the latest work marks a further step towards a scalable quantum Internet.
Harnessing Quantum Entanglement
So from what I understand, teleportation offers a better way of sending quantum information. The protocol for quantum teleportation owes its name to similarities with teleportation in science-fiction films: the quantum bit disappears on the side of the sender and appears on the side of the receiver. As the quantum bit therefore does not need to travel across the intervening space, there is no chance that it will be lost. This makes quantum teleportation an crucial technique for a future quantum Internet.
Quantum networks offer a super-secure way of transferring information between different locations, or nodes. While these nodes can be connected using ordinary optical fibres, photon losses within the fibres limit the quality, or fidelity, of the connection: when a photon is lost, its quantum information is lost, too. Using quantum entanglement to teleport information directly from one node to another removes this loss mechanism, making it desirable for a future quantum Internet.
So what are we really talking about here?
In order to be able to teleport quantum bits, several ingredients are required: a quantum entangled link between the sender and receiver, a reliable method for reading out quantum processors, and the capacity to temporarily store quantum bits.
The researchers at QuTech have now shown for the first time that they can meet the package of requirements and have demonstrated teleportation between non–adjacent nodes, in other words over a network. They teleported quantum bits from node “Charlie” to node “Alice”, with the help of an intermediate node “Bob”.
The three-node network demonstrated at QuTech in 2021 used quantum bits, or qubits, made from nitrogen-vacancy (NV) centres, which are defects within diamond’s lattice of carbon atoms.
Previous research at QuTech demonstrated that it is possible to teleport quantum bits between two adjacent nodes.
The first step in teleporting quantum information from a sender to a receiver is to establish entanglement between their respective qubits. Performing a so-called Bell state measurement (BSM) on the sender’s qubit causes its quantum state to teleport – meaning that it disappears from the sender’s node and appears, in encrypted form, at the receiver’s node. The quantum state can then be decrypted using the BSM outcome that is sent to the receiver via a classical channel (such as an optical fibre).
Previously, this had only been done with two adjacent network points, traditionally called Alice and Bob. Adding a third point, Charlie, is no easy task, as the entanglement between Alice and Charlie needs to be created via Bob, the intermediate node. It also requires a high fidelity to make the teleportation functional.
To achieve this high fidelity, the QuTech researchers carried out several upgrades. In their previous system, the “heralding” signals that indicate entanglement came from the same photodetectors that detected the photons used for entanglement. This, however, can lead to false heralding signals due to various undesired processes generating a second photon. To avoid this, the team set up an additional detection path that flags the false heralding signals by catching the second photon.
Despite the promise, there are still vital elements missing for the creation of a functional quantum internet.
Ronald Hanson, the QuTech researcher who led the study, says that the team’s next step will be to expand the number of memory qubits, making it possible to run more complex protocols.
The new experiment indicates that scientists can stretch a quantum network across an increasingly large number of sites. What can it lead to?
It’s widely assumed that quantum computers cannot reach their full potential without the magical powers of qubit teleportation, or the 'quantum internet'. The computing, cybersecurity and machine learning implications of quantum computing aren’t totally clear in 2022.
“We are now building small quantum networks in the lab,” said Ronald Hanson, the Delft physicist who oversees the team. “But the idea is to eventually build a quantum internet.”
There’s an inkling for all three, it could be of vital importance.
Innovations have been developed that facilitate quantum teleportation between nodes in a quantum network that do not neighbor each other, paving the way for complex network configurations.
“We are also cooperating with computer scientists to develop the quantum network control stack – a similar stack of control layers that currently run the Internet we all use today”.
Hugues de Riedmatten, a researcher at ICFO in Barcelona, Spain, who was not involved in the study, says that quantum teleportation over non-neighbouring nodes is a significant milestone.
The late Israeli physicist, Asher Peres, who died in 2005, anticipated the phenomenon in the Physical Review Letters in 1993.
“The key feature of quantum teleportation is that the quantum information itself is actually teleported: it does not travel through space or fiber. I think this has huge implications for Space-Tech and our colonization of the solar system and later the galaxy.
Transferring quantum information — the superposition of states — between two network nodes becomes possible through the process of entanglement, which happens when scientists create two or more particles such that the quantum state of each particle cannot be described independently of the state of the others. In this way, researchers have shown they can "teleport" quantum information between two nodes.
Scientific progress seems ripe for a paradigm shift of quantum computing, within the next thirty years.
This technology could profoundly change the way data travels from place to place.
It draws on more than a century of research involving quantum mechanics, a field of physics that governs the subatomic realm and behaves unlike anything we experience in our everyday lives.
Quantum teleportation not only moves data between quantum computers, but it also does so in such a way that no one can intercept it.
This is clearly more advanced than cryptography or the tokenomics we have on blockchain based Web3. In fact many analysts believe Quantum computing will be able to hack Bitcoin and other cryptography based technologies.
The research is described in Nature.
What do you make of its significance?
Spooky Action at a Distance is Here
The entangled pair of qubits, which is the resource for executing the teleportation – the ‘teleporter’ – is prepared by using a signal through fiber.” Another term for this phenomenon was coined by Albert Einstein: “Spooky action at a distance.” He himself deemed it impossible.
Put another way, Quantum teleportation — what he called “spooky action at a distance” — can transfer information between locations without actually moving the physical matter that holds it.
Albert Einstein colorfully dismissed quantum entanglement—the ability of separated objects to share a condition or state—as “spooky action at a distance.” Over the past few decades, however, physicists have demonstrated the reality of spooky action over ever greater distances—even from Earth to a satellite in space.
Diamond samples inside one of the quantum computers at the Delft University of Technology. Gold structures on the diamond surface allow control of the quantum processor.Credit...Matteo Pompili for QuTech
Teleportation has been under experiment for a quarter of a century, starting with photons and moving on to atoms and more complex systems. Five years ago, Jian-Wei Pan, the leading researcher in this field who works at China’s University of Science and Technology, succeeded along with his team in teleporting photons from Earth to the artificial satellite Micius, orbiting at an altitude of 1,400 kilometers.
Here the researchers, working at QuTech—a collaboration between Delft University of Technology and the Netherlands Organization for Applied Scientific Research (TNO). It’s not clear if China has already replicated something like this, or if they would tell the world if they had. I consider China roughly five years ahead in manifesting the quantum internet.
Why It Matters
Researchers believe these devices could one day speed the creation of new medicines, power advances in artificial intelligence and summarily crack the encryption that protects computers vital to national security. Across the globe, governments, academic labs, start-ups and tech giants are spending billions of dollars exploring the technology.
Thanks for reading!