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Primeur weekly 2013-08-12

Special

Hybrid architectures and stream computing are becoming the norm in life sciences ...

Focus

UberCloud successful in bringing HPC Cloud to SMEs - and interview with Wolfgang Gentzsch ...

The Cloud

New IBM Flex Systems allow clients to build larger Clouds in smaller data centres ...

Orion Health chooses HP to support managed health services ...

Oracle Enterprise Manager 12c delivers comprehensive management for Oracle Database 12c ...

Capitalonline taps IBM to offer enhanced Cloud services ...

IBM to help Geraldton become smarter, more sustainable city with new Cloud data centre ...

Adaptive Computing unveils Moab Cloud Optimizer Integration for HP Cloud Service Automation 3.2 ...

EuroFlash

Putting Big Data into Perspective ...

Magnetic switching simplified ...

Quantum communication controlled by resonance in 'artificial atoms' ...

Skoda Auto selects SGI ICE X and SGI UV 2000 HPC systems to accelerate automotive innovation ...

ClusterVision strengthens commercial teams in the UK and Germany ...

Wroclaw University Library turns to IBM Big Data solution to preserve European heritage, open digital archives to the world ...

USFlash

Fujitsu receives order for new supercomputer system from Canon ...

IBM Research creates new foundation to program SyNAPSE chips ...

Google, IBM, Mellanox, NVIDIA, and Tyan announce development group for data centres ...

HP helps New Zealand Government Council boost employee productivity ...

Cray names John Josephakis Vice President of Worldwide Sales ...

CSIRO takes charge of Australia's information overload ...

Supercomputer-enabled metagenomic research explores ecosystems in oceans and microbes in the human esophagus ...

Speed limit set for ultrafast electrical switch ...

SGI reports fourth quarter and fiscal year 2013 financial results ...

NVIDIA reports financial results for second quarter fiscal 2014 ...

How superbug spreads among regional hospitals: a domino effect ...

Quantum communication controlled by resonance in 'artificial atoms'


Ola Jakup Joensen, Niels Bohr Institute
6 Aug 2013 Copenhagen - Researchers at the Niels Bohr Institute, together with colleagues in the US and Australia, have developed a method to control a quantum bit for electronic quantum communication in a series of quantum dots, which behave like artificial atoms in the solid state. The results have been published in the scientific journalPhysical Review Letters.

In a conventional computer, information is made up of bits, comprised of 0's and 1's. In a quantum computer the 0 and 1 states can simultaneously exist, allowing a kind of parallel computation in which a large number of computational states are acted upon by the machine at the same time. This can make a quantum computer exponentially faster than a conventional computer. The problem with the quantum world, however, is that you cannot allow these states to be measured, or all of the quantum magic disappears.

"We have developed a new way of controlling the electrons so that the quantum state can be controlled without measurement, using resonances familiar in atomic physics, now applied to these artificial atoms", explained Professor Charles Marcus, director of the Center for Quantum Devices at the Niels Bohr Institute at the University of Copenhagen.

He explained that they are combining classical solid-state physics on a nanometer scale with resonance techniques of atomic physics. In a semiconducting material (GaAs) there are free electrons that move within the material structure. The information is stored in the spin of the electrons which can turn up or down. But the electrons and their spin must be controlled.

"We capture the electrons in 'boxes'. Each box consist of a quantum dot, which is an artificial atom. The quantum dots are embedded in the semiconductor and each quantum dot can capture one electron. There needs to be three quantum dots next to each other using nanometer-scale electrostatic metal gates. When we open contact between the 'boxes' the electrons can sense each others' presence. The three spins must co-ordinate their orientations because it cost extra energy to put electrons with the same spin into the same box. To lower their energy, they not only spread out among the three boxes, but they orient their spins to further lower their energy. The three boxes together form a single entity - a qubit or quantum bit", explained Professor Marcus.

An electrical signal is now sent from outside and by rapidly opening the boxes the system begins to swing in dynamic vibrations. The researchers can use this to change the quantum state of the electrons. "By combining three electrons in a triple quantum dot and oscillating an applied electric field at the frequency that separates adjacent energy levels, we can thus control the spins of the electrons without measuring them", explained Charles Marcus.

First, the technique itself was discovered. The next step is not just a single sequence with three quantum dots, but several sequences. Each sequence forms one qubit and now a series of qubits need to talk to each other. This could be realised by a quantum computer with more bits.

"The potential of a quantum computer is that it will be able to perform multiple calculations at once. In that way it will be much faster than conventional computers and will be able to solve tasks that cannot currently be solved, because it simply takes too long", stated Charles Marcus.

Quantum computers are not expected to be something everyone will own, but rather an advanced set of tools for researchers who need to make extreme calculations.

Source: University of Copenhagen - Niels Bohr Institute

Back to Table of contents

Primeur weekly 2013-08-12

Special

Hybrid architectures and stream computing are becoming the norm in life sciences ...

Focus

UberCloud successful in bringing HPC Cloud to SMEs - and interview with Wolfgang Gentzsch ...

The Cloud

New IBM Flex Systems allow clients to build larger Clouds in smaller data centres ...

Orion Health chooses HP to support managed health services ...

Oracle Enterprise Manager 12c delivers comprehensive management for Oracle Database 12c ...

Capitalonline taps IBM to offer enhanced Cloud services ...

IBM to help Geraldton become smarter, more sustainable city with new Cloud data centre ...

Adaptive Computing unveils Moab Cloud Optimizer Integration for HP Cloud Service Automation 3.2 ...

EuroFlash

Putting Big Data into Perspective ...

Magnetic switching simplified ...

Quantum communication controlled by resonance in 'artificial atoms' ...

Skoda Auto selects SGI ICE X and SGI UV 2000 HPC systems to accelerate automotive innovation ...

ClusterVision strengthens commercial teams in the UK and Germany ...

Wroclaw University Library turns to IBM Big Data solution to preserve European heritage, open digital archives to the world ...

USFlash

Fujitsu receives order for new supercomputer system from Canon ...

IBM Research creates new foundation to program SyNAPSE chips ...

Google, IBM, Mellanox, NVIDIA, and Tyan announce development group for data centres ...

HP helps New Zealand Government Council boost employee productivity ...

Cray names John Josephakis Vice President of Worldwide Sales ...

CSIRO takes charge of Australia's information overload ...

Supercomputer-enabled metagenomic research explores ecosystems in oceans and microbes in the human esophagus ...

Speed limit set for ultrafast electrical switch ...

SGI reports fourth quarter and fiscal year 2013 financial results ...

NVIDIA reports financial results for second quarter fiscal 2014 ...

How superbug spreads among regional hospitals: a domino effect ...