Quantum Computers

Quantum Computers, unlike common computers, are devices that use QUBits instead of bits. Qubits have a superposition, which means that they can be both 0 and 1 at the same time before testing its value. Another property of QUBits is entanglement, which means that one QUBit can instantly manipulate the reaction of the other QUBit, even if they are apart from each other (As far apart as being at the opposite sides of the universe). Entanglement is done by Quantum gates. This technology allows the Quantum devices to run tests, simulations and do research more efficiently, such as database searching, database encrypting (For banking and personal digital information applications) and Quantum simulations.

  • A Burst of ”Synchronous” Light

    Superlattices under the microscope (white light illumination). Empa

    Excited photo-emitters can cooperate and radiate simultaneously, a phenomenon called superfluorescence. Researchers from Empa and ETH Zurich, together with colleagues from IBM Research Zurich, have recently been able to create this effect with long-range ordered nanocrystal superlattices. This discovery could enable future developments in LED lighting, quantum sensing, quantum communication and future quantum computing. The study has just been published in the renowned journal "Nature".

  • A quantum walk of photons

    An electron microscope image of a so-called micropillar with an integrated quantum dot that is capable of emitting single photons.  Photo: Chair for Applied Physics, University of Würzburg

    Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

    The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer. Therefore, it is expected to work out problems in the not too far future which are virtually impossible to solve by classical supercomputers. Physicists refer to this as "quantum computational supremacy".

  • An Atomic Quantum Bit Made Switchable

    Depending on the orientation of an applied magnetic field, quantum tunneling of the magnetisation allows to either freeze or to flip magnetic moments. © University of Augsburg/IfP/EKM

    One bit per atom: Augsburg-based physicists and US colleagues are reaching the ultimate limit for nanoscale data storage

  • Aufruhr auf der Nanoskala – Topologische Isolatoren leisten Widerstand

    Die kleine Kante ist nur rund fünf Atomschichten dick, doch sie reicht aus, um eine feste Theorie ins Wanken zu bringen: An Topologischen Isolatoren, den Hoffnungsträgern z.B. für Quantencomputer, forschen Projektleiter Dr. Christian Bobisch und Sebastian Bauer vom Center for Nanointegration (CENIDE) der Universität Duisburg-Essen (UDE), gefördert von der Deutschen Forschungsgemeinschaft. Sie wiesen nach, dass Kanten auf der Oberfläche die elektrische Leitfähigkeit beeinflussen, indem sie wie kleine Widerstände wirken – was aber gleichzeitig die Tür zu einem präzisen elektronischen Oberflächendesign öffnet. Ihre Erkenntnisse erschienen soeben in der Fachzeitschrift „Nature Communications“.

  • Bug-proof communication with entangled photons

    Fraunhofer IOF‘s quantum source. Designed to be fully operational even after extreme stress. Fraunhofer IOF

    Due to the rapidly growing processing power of computers, conventional encryption of data is becoming increasingly insecure. One solution is coding with entangled photons. Fraunhofer researchers are developing a quantum coding source that allows the transport of entangled photons from satellites, thereby making an important step in the direction of tap-proof communication. In addition to the quantum source, researchers from various Fraunhofer institutes will be presenting other exciting optoelectronic exhibits at the LASER World of Photonics trade fair in Munich from June 26 - 29, 2017 (Hall A2, Booth 431 and Hall B3, Booth 327).

  • Classical mechanics helps control quantum computers: Into the quantum world with a tennis racket

    While the racket rotates 360 degrees about its lateral axis, the tennis racket effect leads to an unintentional 180-degree flip about its longitudinal axis. Credit: Steffen Glaser / TUM

    Quantum technology is seen as an important future-oriented technology: smaller, faster and with higher performance than conventional electronics. However, exploiting quantum effects is difficult because nature’s smallest building blocks have properties quite distinct from those we know from our everyday world. An international team of researchers has now succeeded in extracting a fault tolerant manipulation of quanta from an effect of classical mechanics.

  • Controlled Coupling of Light and Matter

    Artistic representation of a plasmonic nano-resonator realized by a narrow slit in a gold layer. Upon approaching the quantum dot (red) to the slit opening the coupling strength increases. Image: Heiko Groß

    Publishing in a journal like Science Advances usually heralds a particularly exciting innovation. Now, physicists from the Julius-Maximilians-Universität Würzburg (JMU) in Germany and Imperial College London in the UK are reporting controlled coupling of light and matter at room temperature. This achievement is particularly significant as it builds the foundations for a realization of practical photonic quantum technologies.

  • Controlling Quantum States Atom by Atom

    Controlling Quantum States Atom by Atom | Using the tip of a scanning tunnel microscope, a single xenon atom (yellow) is being moved from a quantum box (blue), thus specifically altering its electronic quantum state. (Image: University of Basel, Department of Physics)

    An international consortium led by researchers at the University of Basel has developed a method to precisely alter the quantum mechanical states of electrons within an array of quantum boxes. The method can be used to investigate the interactions between various types of atoms and electrons, which is essential for future quantum technologies, as the group reports in the journal Small.

  • Developing Reliable Quantum Computers

    Illustration: Quantum Optics and Statistics, University of Freiburg

    International research team makes important step on the path to solving certification problems. Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to ensure it is working reliably? Depending on the algorithmic task, this could be an easy or a very difficult certification problem.

  • Error-Free into the Quantum Computer Age

    Quantum error correction protocols detect and correct processing errors in trapped-ion quantum computers. IQOQI Innsbruck/Harald Ritsch

    A study carried out by an international team of researchers and published in the journal Physical Review X shows that ion-trap technologies available today are suitable for building large-scale quantum computers. The scientists introduce trapped-ion quantum error correction protocols that detect and correct processing errors. In order to reach their full potential, today’s quantum computer prototypes have to meet specific criteria: First, they have to be made bigger, which means they need to consist of a considerably higher number of quantum bits. Second, they have to be capable of processing errors.

  • Essential Quantum Computer Component Downsized by Two Orders of Magnitude

    The new nonreciprocal device acts as a roundabout for photons. Here, arrows show the direction of photons propagation. IST Austria/Birgit Rieger

    Researchers at IST Austria have built compact photon directional devices. Their micrometer-scale, nonmagnetic devices route microwave photons and can shield qubits from harmful noise. Qubits, or quantum bits, are the key building blocks that lie at the heart of every quantum computer. In order to perform a computation, signals need to be directed to and from qubits. At the same time, these qubits are extremely sensitive to interference from their environment, and need to be shielded from unwanted signals, in particular from magnetic fields. It is thus a serious problem that the devices built to shield qubits from unwanted signals, known as nonreciprocal devices, are themselves producing magnetic fields.

  • Exotischer Materiezustand: "Flüssige" Quantenspins bei tiefsten Temperaturen beobachtet

    Exotischer Materiezustand Flüssige Quantenspins bei tiefsten Temperaturen beobachtet | Im Kristallgitter von Kalzium-Chrom-Oxid gibt es sowohl ferromagnetische Wechselwirkungen (grüne und rote Balken) als auch antiferromagnetische (blaue Balken). Abbildung: HZB

    Ein Team am HZB hat experimentell eine sogenannte Quanten-Spinflüssigkeit in einem Einkristall aus Kalzium-Chrom-Oxid nachgewiesen. Dabei handelt es sich um einen neuartigen Materiezustand. Das Besondere an dieser Entdeckung: Nach gängigen Vorstellungen war das Quantenphänomen in diesem Material gar nicht möglich. Nun liegt eine Erklärung vor. Die Arbeit erweitert das Verständnis von kondensierter Materie und könnte auch für die zukünftige Entwicklung von Quantencomputern von Bedeutung sein. Die Ergebnisse sind nun in Nature Physics veröffentlicht.

  • First experimental quantum simulation of particle physics phenomena

    First experimental quantum simulation of particle physics phenomena | Physicists have simulated the creation of elementary particle pairs out of the vacuum by using a quantum computer. IQOQI/Harald Ritsch

    Physicists in Innsbruck have realized the first quantum simulation of lattice gauge theories, building a bridge between high-energy theory and atomic physics. In the journal Nature, Rainer Blatt‘s and Peter Zoller’s research teams describe how they simulated the creation of elementary particle pairs out of the vacuum by using a quantum computer.

  • First quantum photonic circuit with electrically driven light source

    Graphic representation of part of a chip, showing with photon source, detector and waveguides Illustration: Münster University/Wolfram Pernice

    Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.

  • Further Improvement of Qubit Lifetime for Quantum Computers

    Illustration of the filtering of unwanted quasiparticles (red spheres) from a stream of superconducting electron pairs (blue spheres) using a microwave-driven pump. Philip Krantz, Krantz NanoArt

    New Technique Removes Quasiparticles from Superconducting Quantum Circuits - An international team of scientists has succeeded in making further improvements to the lifetime of superconducting quantum circuits. An important prerequisite for the realization of high-performance quantum computers is that the stored data should remain intact for as long as possible. The researchers, including Jülich physicist Dr. Gianluigi Catelani, have developed and tested a technique that removes unpaired electrons from the circuits. These are known to shorten the qubit lifetime (to be published online by the journal Science today.

  • Interference as a New Method for Cooling Quantum Devices

    A physical realization of a thermal rectifier. © Shabir Barzanjeh, André Xuereb, Matteo Aquilina, 2018

    Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters. Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature increase due to the thermal noise that is produced by environment and or other components nearby.

  • Light Controls Two-Atom Quantum Computation

    Fig. 1 = see picture description below the text. Graphic: MPQ, Quantum Dynamics Division

    MPQ scientists realize mathematical operations with a quantum gate between two trapped atoms that is mediated by photons. Some powerful rulers of the world may dream of the possibility to get in touch with their colleagues on different continents unnoticed by friends or foes. Someday, new quantum technologies could allow for making these wishes come true.

  • Long-Lived Storage of a Photonic Qubit for Worldwide Teleportation

    Sketch of an optimized optical antenna: A cavity is located inside; the electrical fields during operation are coded by the colour scale. Current patterns are represented by green arrows. Picture: Thorsten Feichtner

    MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network. Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor Gerhard Rempe at the Max Planck Institute of Quantum Optics (MPQ) have now achieved a major breakthrough: they demonstrated the long-lived storage of a photonic qubit on a single atom trapped in an optical resonator.

  • Midwife and Signpost for Photons

    Sketch of an optimized optical antenna: A cavity is located inside; the electrical fields during operation are coded by the colour scale. Current patterns are represented by green arrows. Picture: Thorsten Feichtner

    Targeted creation and control of photons: This should succeed thanks to a new design for optical antennas developed by Würzburg scientists. Atoms and molecules can be made to emit light particles (photons). However, without external intervention this process is inefficient and undirected. If it was possible to influence the process of photon creation fundamentally in terms of efficiency and emission direction, new technical possibilities would be opened up such as tiny, multifunctional light pixels that could be used to build three-dimensional displays or reliable single-photon sources for quantum computers or optical microscopes to map individual molecules.

  • New Quantum States for Better Quantum Memories

    An artificial diamond under the optical microscope. The diamond fluoresces because due to a number of nitrogen defects. TU Wien

    How can quantum information be stored as long as possible? An important step forward in the development of quantum memories has been achieved by a research team of TU Wien. Conventional memories used in today’s computers only differentiate between the bit values 0 and 1. In quantum physics, however, arbitrary superpositions of these two states are possible. Most of the ideas for new quantum technology devices rely on this “Superposition Principle”. One of the main challenges in using such states is that they are usually short-lived. Only for a short period of time can information be read out of quantum memories reliably, after that it is irrecoverable.