News

Belle Dumé at NanotechWeb writes: ''A new way to make complete and programmable logic circuits that combine both memory and logical processing in a single structure has been unveiled by physicists in Germany. Such structures could lead to smaller, faster and more energy-efficient integrated circuits and their development has been one of the main goals in spintronics – a relatively new technology that exploits the spin of an electron as well as its charge.

The electronic chips of the future might not be made of silicon or even graphene but of a material called molybdenite (MoS2). EU-funded research presented in the journal Nature Nanotechnology demonstrates that molybdenite is a highly effective semi-conductor that could be used to make transistors both smaller and more energy efficient.

James Dacey writes at PhysicsWorld: ''An international research group claims to have taken an essential step towards silicon-based quantum computing by entangling 10 billion identical quantum bits, or "qubits", inside a silicon crystal. This is the first time that "ensemble entanglement" has been demonstrated in a solid-state device, they claim. Where conventional computers store data as "bits" with value 1 or 0, in quantum computing data is stored as "qubits", which can hold more than one value at the same time.

Jon Cartwright at PhysicsWorld writes: ''Two independent groups have demonstrated how a pair of entangled photons can transfer their entanglement to and from a solid – the process that should one day form the backbone of so-called quantum memories or repeaters. These devices would enable quantum communication systems to transmit information over larger distances, with significantly reduced degradation.''

Often we hear from young researchers that they have violated a Bell inequality with their new source by this and this factor. In such cases we usually forget about three basic underlying assumptions. Two of them are well known; Realism stating that outcomes of measurements exist before they are revealed in a measuring act and Locality forbidding superluminal communication between spatially separated laboratories. The third important assumption is Freedom exercised by the observers to choose their local measurements independently of each other.
<!--break-->

This special issue of International Journal Of Quantum Information is aimed to collect papers addressing both fundamental problems and applications, thus offering to readers comprehensive and up-to-date overview on the characterization and use of quantum correlations. We welcome papers that address fundamental aspects of quantum and classical correlations in discrete and continuous variable systems, propose implementations to make quantitative measurements of quantum correlations, or describe experiments that exploit quantum correlations as a resource for quantum technology.

EU-funded scientists in the Netherlands have managed to rapidly control the building blocks of a quantum computer by using an electric field rather than a magnetic one. In addition, the team succeeded in embedding these building blocks, known as quantum bits or qubits, in a semiconductor nanowire. The study, published in the journal Nature, could lead to advances in the field of quantum computing and communication.

Jon Cartwright at PhysicsWorld writes: ''Physicists in the US and the UK have found a way to store and read data in nuclear spins using electronic pulses. The breakthrough could help in the development of spintronic systems that process information using spins – and could also find applications in quantum computation.''

Kate McAlpine at PhysicsWorld writes: ''Since quantum mechanics was first formulated, a string of physicists including Albert Einstein have been uncomfortable with the idea of entanglement – whereby a group of quantum particles have a closer relationship than allowed by classical physics. As a result, some physicists have proposed alternative theories that allow such close relationships without the need for quantum mechanics.

Chris Lee at ArsTechnics writes: ''Not so long ago, we reported on a paper that purported to blow a hole in quantum key distribution (QKD) systems. Now, researchers at Toshiba have struck back with findings that show that the attack doesn't really work. To which the original authors have replied, "Well, it depends." ''