ScienceDaily: Quantum Computing News

First direct proof of Hofstadter butterfly fractal observed in moiré superlattices

Wed, 15 May 2013 13:15:15 EDT

Scientists have directly observed a rare quantum effect that produces a repeating butterfly-shaped energy spectrum, confirming the longstanding prediction of this quantum fractal energy structure called Hofstadter's butterfly.

Observation of second sound in a quantum gas

Wed, 15 May 2013 13:15:15 EDT

Second sound is a quantum mechanical phenomenon, which has been observed only in superfluid helium. Physicists have now proven the propagation of such a temperature wave in a quantum gas.

Squishy hydrogels may be the ticket for studying biological effects of nanoparticles

Wed, 15 May 2013 12:51:51 EDT

A class of water-loving, jelly-like materials with uses ranges ranging from the mundane, such as superabsorbent diaper liners, to the sophisticated, such as soft contact lenses, could be tapped for a new line of serious work: testing the biological effects of nanoparticles, according to scientists.

Obtaining polymers with à la carte optical and electrical properties

Wed, 15 May 2013 08:53:53 EDT

Scientists have created nanostructured composite materials with specific optical and electrical properties that vary according to size. These properties allow researchers to synthesize particles of the size corresponding to the desired properties, and by adding these particles to polymers, to give the final product one specific property or another.

New principle may help explain why nature is quantum

Tue, 14 May 2013 11:27:27 EDT

Like small children, scientists are always asking the question 'Why?'. One question they've yet to answer is why nature picked quantum physics, in all its weird glory, as a sensible way to behave. Researchers tackle this perennial question in a new paper.

Photonic quantum computers: A brighter future than ever

Mon, 13 May 2013 10:38:38 EDT

Harnessing the unique features of the quantum world promises a dramatic speed-up in information processing as compared to the fastest classical machines. Scientists have succeeded in prototyping a new and highly resource efficient model of a quantum computer -- the boson sampling computer.

Graphene joins the race to redefine the ampere

Sun, 12 May 2013 14:12:12 EDT

New research could pave the way for redefining the ampere in terms of fundamental constants of physics. The world's first graphene single-electron pump provides the speed of electron flow needed to create a new standard for electrical current based on electron charge.

Perfectly doped quantum dots yield 'colors to dye for'

Fri, 10 May 2013 12:45:45 EDT

This focuses on an ultra-precise method for doping the tiny semiconductors produces vivid hues.

Flawed diamonds promise sensory perfection: Electron spin extended for incredibly tiny magnetic detectors

Fri, 10 May 2013 10:21:21 EDT

By extending the coherence time of electron states to over half a second, scientists have improved the performance of one of the most potent sensors of magnetic fields on the nanoscale -- a diamond defect no bigger than a pair of atoms called a nitrogen vacancy center. The achievement is important news for nanoscale sensors and quantum computing.

Device for portable, ultra-precise clocks and quantum sensors developed

Thu, 09 May 2013 09:08:08 EDT

Researchers have developed a portable way to produce ultracold atoms for quantum technology and quantum information processing.

Graphene quantum dots may someday tell if it will rain on Mars

Wed, 08 May 2013 13:18:18 EDT

Chemical engineers may be able to improve humidity and pressure sensors, particularly those used in outer space.

Speed test of quantum versus conventional computing: Quantum computer wins

Wed, 08 May 2013 12:28:28 EDT

A quantum computer system is “thousands of times faster” than conventional computing in solving an important problem type, a computer science professor finds.

Quantum optics with microwaves: Hong-Ou-Mandel effect demonstrated

Wed, 08 May 2013 09:30:30 EDT

Physicists have demonstrated one of the quintessential effects of quantum optics -- known as the Hong-Ou-Mandel effect -- with microwaves, whose frequency is 100,000 times lower than that of visible light. The experiment takes quantum optics into a new frequency regime and could eventually lead to new technological applications.

Elucidating energy shifts in optical tweezers

Wed, 08 May 2013 09:29:29 EDT

Physicists are providing an all-in-one guide to help calculate the effect the use of optical tweezers has on the energy levels of atoms under study. A small piece of paper sticks to an electrically charged plastic ruler. The principle of this simple classroom physics experiment is applied at the microscopic scale by so-called optical tweezers to get the likes of polystyrene micro-beads and even living cells to "stick" to a laser beam, or to trap atoms at ultra-low temperatures.

Highly fragile, volatile body observed with new quantum-mechanical measurement technique

Sun, 05 May 2013 14:59:59 EDT

Scientists have observed a highly fragile and volatile body through a new quantum-mechanical measurement technique.

How to frustrate a quantum magnet: 16 atomic ions simulate a quantum antiferromagnet

Fri, 03 May 2013 10:50:50 EDT

Frustration crops up throughout nature when conflicting constraints on a physical system compete with one another. The way nature resolves these conflicts often leads to exotic phases of matter that are poorly understood. In a new article, researchers describe how to frustrate a quantum magnet composed of sixteen atomic ions -- to date the largest ensemble of qubits to perform a simulation of quantum matter.

Use of laser light yields versatile manipulation of a quantum bit

Wed, 01 May 2013 14:51:51 EDT

By using light, researchers have manipulated the quantum state of a single atomic-sized defect in diamond -- the nitrogen-vacancy center -- in a method that not only allows for more unified control than conventional processes, but is more versatile, and opens up the possibility of exploring new solid-state quantum systems.

Best of both worlds: Towards a quantum Internet with combined optical and electrical technique

Wed, 01 May 2013 13:18:18 EDT

Scientists have achieved a breakthrough in quantum science that brings the prospect of a network of ultra-powerful quantum computers -- connected via a quantum internet -- closer to reality. The team is the first to have detected the spin, or quantum state, of a single atom using a combined optical and electrical approach.

Graphene's high-speed seesaw

Tue, 30 Apr 2013 13:13:13 EDT

A new transistor capable of revolutionizing technologies for medical imaging and security screening has been developed by graphene researchers. The researchers report the first graphene-based transistor with bistable characteristics, which means that the device can spontaneously switch between two electronic states. Such devices are in great demand as emitters of electromagnetic waves in the high-frequency range between radar and infra-red, relevant for applications such as security systems and medical imaging.

One step closer to a quantum computer

Tue, 30 Apr 2013 09:24:24 EDT

Scientists have succeeded in both initializing and reading nuclear spins, relevant to qubits for quantum computers, at room temperature.

Movement of pyrrole molecules defy 'classical' physics

Fri, 26 Apr 2013 11:54:54 EDT

Quantum laws loom ever larger in physical world as new research finds quantum phenomena in effect on a molecular level.

The crystal's corners: New nanowire structure has potential to increase semiconductor applications

Tue, 23 Apr 2013 13:57:57 EDT

New research describes the discovery of a new structure that is a fundamental game changer in the physics of semiconductor nanowires.

Scientists provide 'new spin' on emerging quantum technologies

Tue, 23 Apr 2013 09:10:10 EDT

Scientists have shed new light on a fundamental area of physics which could have important implications for future electronic devices and the transfer of information at the quantum level.

Technique unlocks design principles of quantum biology

Fri, 19 Apr 2013 12:09:09 EDT

Researchers have created a synthetic compound that mimics the complex quantum dynamics observed in photosynthesis and may enable fundamentally new routes to creating solar-energy technologies.

A new twist for quantum systems

Wed, 17 Apr 2013 13:18:18 EDT

Physicists have developed a method for precisely controlling quantum systems by exploiting a trick that helps cats to land on their feet and motorists to fit their cars into parking spots. In the longer run, the method could lead to the development of more reliable quantum computers.

Quantum computing taps nucleus of single atom

Wed, 17 Apr 2013 13:18:18 EDT

Australian engineers have demonstrated that quantum information can be "written" onto the nucleus of a single atom and "read" out with incredible accuracy. The result was achieved using a silicon chip that can be wired up and operated electronically.

Photons run out of loopholes: Quantum world really is in conflict with our everyday experience

Mon, 15 Apr 2013 12:49:49 EDT

Physicists have carried out an experiment with photons in which they have closed an important loophole. The researchers have thus provided the most complete experimental proof that the quantum world is in conflict with our everyday experience.

'Spooky action at a distance' in the quantum world shortly before final proof

Mon, 15 Apr 2013 09:48:48 EDT

Physicists have succeeded in closing the last local realistic loophole for systems of entangled photons.

Bose-Einstein condensates evaluated for quantum computers

Thu, 11 Apr 2013 10:58:58 EDT

Physicists have examined how Bose-Einstein condensates (BEC) might be used to provide communication among the nodes of a distributed quantum computer. The researchers determined the amount of time needed for quantum information to propagate across their BEC.

Advancing secure communications: A better single-photon emitter for quantum cryptography

Tue, 09 Apr 2013 14:50:50 EDT

In a development that could make the advanced form of secure communications known as quantum cryptography more practical, researchers have demonstrated a simpler, more efficient single-photon emitter that can be made using traditional semiconductor processing techniques.

A step toward optical transistors?

Tue, 09 Apr 2013 12:47:47 EDT

Researchers have demonstrated a new way to control light in semiconductor nanocrystals.

Don't call it vaporware: Scientists use cloud of atoms as optical memory device

Thu, 04 Apr 2013 09:28:28 EDT

Talk about storing data in the cloud. Scientists have taken this to a whole new level by demonstrating that they can store visual images within quite an ethereal memory device -- a thin vapor of rubidium atoms. The effort may prove helpful in creating memory for quantum computers.

Quantum tricks drive magnetic switching into the fast lane

Wed, 03 Apr 2013 20:03:03 EDT

Researchers in the U.S. and Greece have found a new way to switch magnetism that is at least 1000 times faster than currently used in magnetic memory technologies. Magnetic switching is used to encode information in hard drives, RAM and other computing devices.

Building quantum states with individual silicon atoms

Wed, 03 Apr 2013 11:27:27 EDT

By introducing individual silicon atom 'defects' using a scanning tunneling microscope, scientists have coupled single atoms to form quantum states.

Quantum cryptography: On wings of light

Wed, 03 Apr 2013 07:19:19 EDT

Physicists have, for the first time, successfully transmitted a secure quantum code through the atmosphere from an aircraft to a ground station.

Quantum dot commands light: A solid state ultrafast logic gate on a photon

Mon, 01 Apr 2013 09:26:26 EDT

If you could peek at the inner workings of a computer processor you would see billions of transistors switching back and forth between two states. In optical communications, information from the switches can be encoded onto light, which then travels long distances through glass fiber. Researchers are working to harness the quantum nature of light and semiconductors to expand the capabilities of computers in remarkable ways.

Quantum computing? Physicists' new technique for cooling molecules may be a stepping stone to quantum computing

Wed, 27 Mar 2013 14:41:41 EDT

At the heart of next-generation computers may be a collection of ultracold molecules held at temperatures a mere fraction of a degree above absolute zero. By combining two traditional atomic cooling technologies, physicists have pioneered a new technique for bringing normally springy molecules to a frozen standstill. Their results may be an important stepping stone towards future quantum computing.

Speed of light may not be fixed, scientists suggest; Ephemeral vacuum particles induce speed-of-light fluctuations

Mon, 25 Mar 2013 11:11:11 EDT

Two new articles challenge established wisdom about the nature of vacuum. In one article scientists have identified a quantum level mechanism for interpreting vacuum as being filled with pairs of virtual particles with fluctuating energy values. As a result, the inherent characteristics of vacuum, like the speed of light, may not be a constant after all, but fluctuate.

Quantum computers coming soon? Metamaterials used to observe giant photonic spin Hall effect

Thu, 21 Mar 2013 15:19:19 EDT

Engineering a unique metamaterial of gold nanoantennas, researchers were able to obtain the strongest signal yet of the photonic spin Hall effect, an optical phenomenon of quantum mechanics that could play a prominent role in the future of computing.

Quantum computers counting on carbon nanotubes

Thu, 21 Mar 2013 14:15:15 EDT

Carbon nanotubes can be used as quantum bits for quantum computers. A study by physicists has shown how nanotubes can store information in the form of vibrations. Up to now, researchers have experimented primarily with electrically charged particles. Because nanomechanical devices are not charged, they are much less sensitive to electrical interference.

Laser-like photons signal major step towards quantum 'Internet'

Tue, 19 Mar 2013 12:42:42 EDT

The realization of quantum networks is one of the major challenges of modern physics. Now, new research shows how high-quality photons can be generated from "solid-state" chips, bringing us closer to the quantum "Internet."

Causing collapse: Can one affect an atom's spin just by adjusting the way it is measured?

Mon, 18 Mar 2013 13:30:30 EDT

One of the most basic laws of quantum mechanics is that a system can be in more than one state -- it can exist in multiple realities -- at once. This phenomenon, known as the superposition principle, exists only so long as the system is not observed or measured in any way. As soon as such a system is measured, its superposition collapses into a single state. Thus, we, who are constantly observing and measuring, experience the world around us as existing in a single reality. Researchers now suggest one can affect an atom's spin just by adjusting the way it is measured.

Smallest vibration sensor in the quantum world

Fri, 15 Mar 2013 09:59:59 EDT

Carbon nanotubes and magnetic molecules are considered building blocks of future nanoelectronic systems. Their electric and mechanical properties play an important role. Researchers have now found a way to combine both components on the atomic level and to build a quantum mechanical system with novel properties.

Chemical chameleon tamed: Researchers give floppy molecule a structure through solvent effects

Thu, 14 Mar 2013 08:50:50 EDT

How you get the chameleon of the molecules to settle on a particular "look" has been discovered by chemists in Germany. The molecule CH5+ is normally not to be described by a single rigid structure, but is dynamically flexible. By means of computer simulations, the team showed that CH5+ takes on a particular structure once you attach hydrogen molecules.

Electrons behaving like a particle and a wave: Feynman's double-slit experiment brought to life

Wed, 13 Mar 2013 21:40:40 EDT

The precise methodology of Richard Feynman's famous double-slit thought-experiment -- a cornerstone of quantum mechanics that showed how electrons behave as both a particle and a wave -- has been followed in full for the very first time.

Mechanical micro-drum used as quantum memory

Wed, 13 Mar 2013 14:25:25 EDT

Researchers have demonstrated that information encoded as a specific point in a traveling microwave signal -- the vertical and horizontal positions of a wave pattern at a certain time -- can be transferred to the mechanical beat of a micro-drum and later retrieved with 65 percent efficiency.

Quantum magnets moving along: Scientists observes coherent propagation of a single spin impurity in a chain of ultracold atoms

Wed, 13 Mar 2013 09:54:54 EDT

Many discoveries in physics came as a big surprise -- for example the phenomenon, that some materials loose almost all their electrical resistance at low temperatures, or that others become superconductors at unexpectedly high temperatures. In the past it was mainly due to theoreticians to develop models explaining these unusual properties. Unfortunately it is not possible to have a direct look into a solid state crystal and follow up the motion of charge carriers as this process happens at extremely short time and length scales. Scientists have now observed the coherent propagation of single spin excitations in an ultracold quantum gas of strongly correlated atoms.

Quantum refrigerator offers extreme cooling and convenience

Fri, 08 Mar 2013 18:38:38 EST

Researchers have demonstrated a solid-state refrigerator that uses quantum physics in micro- and nanostructures to cool a much larger object to extremely low temperatures. What's more, the prototype refrigerator, which measures a few inches in outer dimensions, enables researchers to place any suitable object in the cooling zone and later remove and replace it, similar to an all-purpose kitchen refrigerator.

The future of ion traps: Technology will continue to be leader in development of quantum computing architectures

Thu, 07 Mar 2013 14:57:57 EST

Scientists speculate on ion trap technology as a scalable option for quantum information processing.

Engineering breakthrough promises significantly more efficient solar cells

Thu, 07 Mar 2013 14:57:57 EST

A new technique could lead to significantly more efficient solar cells. Quantum dot photovoltaics offers the potential for low-cost, large-area solar power -- however these devices are not yet highly efficient in the infrared portion of the sun's spectrum, which is responsible for half of the sun's power that reaches Earth. The solution? Spectrally tuned, solution-processed plasmonic nanoparticles. These particles, researchers say, provide unprecedented control over light's propagation and absorption.

Curtains down for the black hole firewall paradox: Making gravity safe for Einstein again

Wed, 06 Mar 2013 08:41:41 EST

Scientists have revealed new insights into the life and death of black holes. Their findings dispel the so-called firewall paradox which shocked the physics community when it was announced in 2012 since its predictions about large black holes contradicted Einstein's crowning achievement -- the theory of general relativity. Those results suggested that anyone falling into a black hole would be burned up as they crossed its edge -- the so-called event horizon.

Quantum realm: Forging new pathways to quantum devices

Mon, 04 Mar 2013 15:18:18 EST

Physicists are manipulating light on superconducting chips, and forging new pathways to building the quantum devices of the future -- including super-fast and powerful quantum computers.

Getting around the uncertainty principle: Physicists make first direct measurements of polarization states of light

Sun, 03 Mar 2013 15:49:49 EST

Researchers have applied a recently developed technique to directly measure for the first time the polarization states of light. Their work both overcomes some important challenges of Heisenberg's famous Uncertainty Principle and also is applicable to qubits, the building blocks of quantum information theory.

Turbulence in a crystal

Fri, 01 Mar 2013 05:16:16 EST

When a crystal is hit by an intense ultrashort light pulse, its atomic structure is set in motion. Scientists can now observe how the configuration of electrons and atoms in titanium dioxide, a semiconductor, changes under the impact of an ultraviolet laser pulse, confirming that even subtle changes in the electron distribution caused by the excitation can have a considerable impact on the whole crystal structure.

Space race underway to create quantum satellite

Thu, 28 Feb 2013 19:46:46 EST

A new article describes how a quantum space race is under way to create the world's first global quantum-communication network.

Atoms with quantum-memory

Thu, 28 Feb 2013 08:02:02 EST

Order tends towards disorder. This is also true for quantum states. Measurements show that in quantum mechanics this transition can be quite different from what we experience in our daily lives.

Connecting the (quantum) dots: First viable high-speed quantum computer moves closer

Tue, 26 Feb 2013 11:40:40 EST

Scientists have developed a new method that better preserves the units necessary to power lightning-fast electronics, known as qubits. Hole spins, rather than electron spins, can keep quantum bits in the same physical state up to 10 times longer than before, the report finds.

Newly observed properties of vacuums: Light particles illuminate the vacuum

Tue, 26 Feb 2013 09:21:21 EST

Researchers have succeeded in showing experimentally that vacuums have properties not previously observed. According to the laws of quantum mechanics, it is a state with abundant potentials. Vacuums contain momentarily appearing and disappearing virtual pairs, which can be converted into detectable light particles.

Quantum algorithm breakthrough: Performs a true calculation for the first time

Sun, 24 Feb 2013 14:28:28 EST

Scientists have demonstrated a quantum algorithm that performs a true calculation for the first time. Quantum algorithms could one day enable the design of new materials, pharmaceuticals or clean energy devices.

Quantum dots that assemble themselves

Wed, 20 Feb 2013 10:07:07 EST

Scientists have demonstrated a process whereby quantum dots can self-assemble at optimal locations in nanowires, a breakthrough that could improve solar cells, quantum computing, and lighting devices.