The Quantum Internet

 Quantum Internet: at the Verge of an Emerging Technology

- Overview

The quantum internet is a network of quantum computers that will send, receive, and compute information encoded in quantum states. It will not replace the current internet, but will instead provide new features like quantum cloud computing and quantum cryptography. 

The quantum internet will involve sending qubits across a network of physically separated quantum devices. Qubits are data encoded in the state of quantum devices like a quantum computer or a quantum processor. 

The quantum internet's vision is to improve internet technology by enabling quantum communication between any two points on Earth. It could also enable distributed quantum computing, where multiple computers work together to solve complex problems.

Quantum computers have the potential to perform certain types of computations much faster than classical computers. Some say that quantum computers will shrink down to a size and cost viable for consumer use toward the end of the 2030s and early 2040s.

- The Aim of the Quantum Internet

Today’s Internet is a playground for hackers. From insecure communication links to inadequately guarded data in the cloud, vulnerabilities are everywhere. 

The main advantages of a quantum communication network over a conventional one are speed and security. Entanglement makes it possible to communicate instantly across arbitrarily large distances in principle. No matter how far apart you put two entangled qubits, acting on one will have an instant and measurable impact on the other.

The Quantum Internet is a communication network with quantum nodes and quantum links that allows to the parties to perform efficient quantum communications. 

The aim of the quantum Internet and quantum repeater networks is to distribute quantum entanglement between distant nodes through a chain of intermediate quantum repeater nodes. 

In the quantum Internet, the quantum nodes share entangled connections that formulate entangled links. 

- The Quantum Internet Technology

The quantum Internet could revolutionize how computers talk to each other. Parts of the quantum Internet will be realized by sending quantum light through waveguides, such as optical fibres, that are connected to quantum devices. The ultimate vision of the quantum Internet is a connection of potentially billions of quantum devices within the same network. But it's hard to model such complex networks theoretically, and existing models can only cope with very simple networks.

The Quantum Internet technology is something that today only really exists on paper and on the drawing boards of scientists. Yet, it is now a great moment to start discussing its potential, as a lot of research effort is being made towards the realization of such a quantum Internet. 

Although a fully realized quantum network is still a far-off vision, recent breakthroughs in transmitting, storing and manipulating quantum information have convinced some quantum physicists that a simple proof-of-principle is imminent.

- Quantum Teleportation

With advances in quantum computing, many experts in the quantum industry are concerned about when the quantum internet (a network in which quantum computers and quantum technologies communicate with each other) will emerge. A quantum internet could send signals not only faster, but more securely. 

According to a 2021 paper in the journal Nature: "The quantum internet will be based on a protocol called quantum teleportation, which will transmit quantum information from one node to another over long distances. Teleportation Not only will it help extend quantum communication distances, but it will also be crucial for distributed quantum computing."

It's difficult to predict when next-generation infrastructure will be functional (as it's likely to be launched over shorter distances), but researchers are working on various devices and methods to bring this network closer to reality.

- Quantum Entanglement

In quantum entanglement, particles interacting at a certain point retain a connection and can become entangled with each other in pairs, a process called correlation. Knowing the spin state of an entangled particle -- up or down -- can tell one that its partner's spin is in the opposite direction. 

Quantum entanglement allows qubits separated by incredible distances to interact instantaneously (not limited to the speed of light). Regardless of the distance between related particles, as long as they are isolated, they remain entangled.

[Venus - NASA]

- Quantum Teleportation

Quantum teleportation is a technique for transmitting quantum information from a sender in one location to a receiver some distance away. While teleportation is described in science fiction as a means of transferring physical objects from one location to another, quantum teleportation only transmits quantum information. 

A team of scientists and researchers has achieved, for the first time, sustained, high-fidelity "quantum teleportation" -- the instant transmission of "qubits" (qubits), the basic units of quantum information. A collaborative team, including NASA's Jet Propulsion Laboratory, has successfully demonstrated sustained long-distance teleportation of photonic qubits (light quanta) with over 90 percent fidelity. The qubits are teleported 44 kilometers (27 miles) over a fiber-optic network using state-of-the-art single-photon detectors and off-the-shelf equipment.

- Quantum Teleportation: Paving the Way for a Quantum Internet

In July, 2020, the U.S. Department of Energy unveiled a blueprint for the first quantum internet, linking its multiple national laboratories across the country. A quantum internet will be able to transmit massive amounts of data over great distances at speeds exceeding the speed of light. You can imagine all the applications that could benefit from this kind of speed.

A consensus is emerging around the world that systems that communicate using quantum mechanics represent one of the most important technological frontiers of the 21st century. Scientists now believe that construction of a prototype will be possible within the next decade.

- Quantum Internet: Hybrid Quantum Information Network

Quantum information networks are emerging as a disruptive technology, providing entirely new capabilities for information processing and communication, which will have a huge impact on the most secure internet connections and access in the future.

The researchers published their results, realizing a fundamental hybrid quantum network link. They demonstrated photonic quantum communication between two distinct quantum nodes placed in different laboratories, using a single photon as an information carrier. The researchers demonstrated the network using a telecommunications wavelength of 1552 nm.

The ability to transmit qubits via single photons between them is an important step in the development of hybrid quantum networks. Note that the classic information network, the World Wide Web, uses bits to keep information flowing across the network, processed and modulated by electronic circuits and chips, and transmitted by pulses of light to move information across the network.

A quantum information network, or quantum internet, processes and stores quantum information through quantum bits, or "qubits," in a quantum network. Therefore, there is the potential advantage of completely secure data transmission, which is one of the most important features required for internet connectivity and access.

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