Quantum Computing with Light
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Quantum Computing with Light


Quantum information is the science that exploits the laws of quantum mechanics… …to enhance our communication and computational capabilities. Future quantum devices will allow us to perform complex… …tasks achievable with classical computers… …and to fundamentally secure transfer of encrypted information. At the University of Sheffield a team of researchers is working to develop… …a computer processing unit… …combining the quantum nature of
light and novel semiconductor technologies. The foundation of this technological step change… …is the quantum bit, or qubit, as the unit of quantum information is known. While a classical bit can only be either 0 or 1… …a qubit can be 0 and 1 at the same time,… …and is said to be in a superposition state of the two. The 1 and the 0 of the qubit… can be represented by the spin up and spin down states of an electron in a wire. Or by the spin states of the nucleus in an atom. Or by the polarisation state of a photon. The main advantage of qubits with respect to classical bits… …can be understood by visualising the computation as a journey… …from A to B in a complex landscape. A classical bit must stick to the roads… …representing the classical values 0 and 1. 0 1 Qubits, however, are a superposition of 0 and 1,… and can therefore take a shortcut through the computational landscape. For this reason the computation requires fewer steps… …and can be faster. Among all the different physical systems,… …which can be used as qubits,… …photons have the advantage that… …having performed a calculation they can also share the result at the speed of light,… …allowing fast and long-distance communications. For these reasons, researchers at the University of Sheffield… …are developing new photonic devices… …combining different chemical elements such as: Galium Arsenic Aluminium and Indium These materials, called III-V semiconductors,… …are particularly suitable for photon manipulation… and are processed in the advanced laboratories of the National Centre for III-V Technologies. The simplest possible quantum circuit with photons… …requires three key components: sources of single identical photons, a beamsplitter, and single photon counters. Single photon sources are implemented using quantum dots,… ..nanostructures able to trap one electron and one hole. When the electron falls into the hole a photon is emitted. Trains of identical photons can be obtained… …by repeating this recombination process in a controllable way. The beam-splitter is implemented using two wires… …that guide photons close together allowing them to interfere. In this way, taking advantage of the Hong-Ou-Mandel effect,… …several different logical operations can be performed. Single photon counters are implemented… …by means of superconducting nanowires. These devices are so sensitive… …that they are able to detect a small change in the electric current… …caused by the arrival of a photon. In this way it is possible to count how many photons arrive… …from each arm of the beam-splitter… …and read out the result of the operation. These three components integrated together… …constitute the core of a scalable platform… …for a quantum chip based on light. Such a platform,… …not dissimilar to present electronic circuits,… …offers extraordinary computational possibilities. And can also be used as a node… …to securely distribute encrypted information over long distances.

21 Comments

  • Genrix Straus

    Неплохо, неплохо. Интересно, информация, содержащиеся в кубитах будет храниться в стандартных средствах хранения информации, применяемые сейчас, или же будут разработаны новые форматы?

  • Tomáš Šindel

    I love that animation and explanation! Seems more professional than most youtube science videos I have seen so far.

  • Pritanis A

    how we can know if the photon will travel at the wire we want?or how we can control it?the superposition "breaks' when the come close to one another but dont we need to entgle them in order to get results ?

  • 21EC

    with strong PCs comes stronger protection but unafortunately hackers will also have these strong PCs…so it also brings better code cracking abillities and that's an issue which will remain, the only thing which can really solve it is if you just never put your files on a PC with online access..so your most important files must simply be stores on an ever offline PC.

  • hussain ahmed

    Perfect real world use case of quantum computing explained. By harnessing quantum entanglement you can send data across the world or to Mars at the speed of light. Imagine instant Skype calls to Mars with no lag or delay.

  • Guido Geeks

    Pazzesco!!! Pazzesco!!! Questo sito mi ha cambiato la vita!!! Non ci credo ancora!!! http://bit.ly/bettingbetter1

  • diggleboy

    This looks like how www.xanadu.ai created their quantum computing unit using light. Excellent video and explanation! I'll be conducting more research into this version of quantum computing, because it seems the most feasible out of all the ones I've seen so far. Based on its physics, it also makes the most sense to me, physically and monetarily.

  • antonio bortoni

    I want a videogame whit that graphics… light computers, make sense. I sometimes imagine light being decomposed and processed in a crystal and the light the pass it will result in process information.

  • Evan O'Leary

    Do the relative lengths of the path with the right angle turn and the diagonal path actually represent the relative efficiencies of classical and quantum computation?

  • Agent Derek Anderson

    Can you ethch a circuit board directly onto a solar panel .. a virtual machine connecting the cloud to silicon ?

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