A solid case of entanglement

For the first time, physicists have convincingly demonstrated that physically separated particles in solid-state devices can be quantum-mechanically entangled. The achievement is analogous to the quantum entanglement of light, except that it involves particles in circuitry instead of photons in optical systems. Both optical and solid-state entanglement offer potential routes to quantum computing and secure communications, but solid-state versions may ultimately be easier to incorporate into electronic devices.

Topological insulators could help define fundamental constants

A newly discovered class of materials known as "topological insulators" could help physicists to obtain new ways of defining the three basic physical constants – the speed of light (c); the charge of the proton (e); and Planck’s constant (h). That’s the claim of a team of physicists in the US, which has proposed a new experiment to measure the fine-structure constant (α), which is a function of h, c and e, by scattering light from such a material. Topological insulators are unusual in that electrical current flows well on their surface, but not through their bulk.

The quest for dilute ferromagnetism in semiconductors: Guides and misguides by theory

A material that exhibits both ferromagnetic and semiconductor properties offers the exciting prospect of combining nonvolatile magnetic storage and conventional semiconductor electronics in a single device. Magnetic semiconductors offer a number of interesting possibilities in the pursuit of  spintronics , a branch of science and technology that exploits the spin dimension of the electron in addition to its charge, for novel electronic devices. These materials combine the properties of a semiconductor and a magnetic material, providing, for instance, a way to create 100 % spin-polarized currents, and by the same token, the promise of electrical control of magnetic effects. While in some magnetic semiconductors, for example, magnetite, all of the material’s constituent ions are intrinsically magnetic (  concentrated magnets  ), the most recent focus has been on nonmagnetic semiconductor host materials that can be doped by a small amount of magnetic transition-metal ions or by defects that promote magnetism (  dilute magnets  ).

Who wants to live for ever? A scientific breakthrough could mean humans live for hundreds of years

A genetically engineered organism that lives 10 times longer than normal has been created by scientists in California. It is the greatest extension of longevity yet achieved by researchers investigating the scientific nature of ageing.

Quantum Time Machine Lets You Travel to the Past Without Fear of Grandfather Paradox

Looking to build a time machine but nervous about the classic grandfather paradox, aka the Marty McFly conundrum, aka the idea that you might unwittingly do something that causes you to never exist in the first place? An MIT professor and a few of his quantum quoting buddies have published a theory that  allows for time travel while circumventing the grandfather paradox . All you need is a quantum teleportation device and a precise understanding of the idea of postselection--Flux Capacitor optional.

Topological insulators: Star material

 A topological insulator sounds simple enough:  A block of material that lets electrons move along its surface, but not through its inside . In fact, it is far from straightforward. Ordinary metals conduct electrons all the way through, whereas ordinary insulators don't conduct electrons at all. A copper-plated block of wood conducts only on the surface, but that is two materials, not one. The idea of a topological insulator is so strange that for a long time, physicists had no reason to believe that such a material would exist .

 Researchers also believe that the collective motions of electrons inside topological insulators will mimic several of the never-before-seen particles predicted by high-energy physicists. Among them are axions, hypothetical particles predicted in the 1970s; magnetic monopoles, single points of north and south magnetism; and Majorana particles — massless, chargeless entities that can serve as their own antiparticles. 

Could some entangled states be useless for quantum cryptography ?

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One of the widely accepted properties of quantum entanglement is secrecy. Since scientists and researchers began working with quantum key distribution, entanglement has been considered an essential part of keeping communications private. What if entanglement didn't always mean secrecy, though ? New work is shedding light on the nature of entanglement and quantum key distribution -  and possibly proving that a high degree of entanglement does not necessarily lead to complete secrecy .

What Is Time? One Physicist Hunts for the Ultimate Theory

One way to get noticed as a scientist is to tackle a really difficult problem. Physicist Sean Carroll has become a bit of a rock star in geek circles by attempting to answer an age-old question no scientist has been able to fully explain: What is time ?.

Dropping ultra-cold quantum gas down an elevator shaft could help prove Einstein wrong

Scientists have shown that it’s possible to keep sufficiently close tabs on quantum mechanical objects in free fall to tell whether two such objects experience gravity the same way. In 1907, Einstein suggested that if you were in a windowless elevator that was plunging towards Earth in free fall, you would feel the same weightlessness as if you were floating in outer space. This notion, known as the equivalence principle, laid the foundation for general relativity. It explains why a pebble and a piano fall at the same speed if dropped from the same roof, despite their different masses. It’s also a necessary first step toward describing the effects of gravity as curvature in spacetime.

Read More http://www.wired.com/wiredscience/2010/06/quantum-gravity-in-an-elevator/#ixzz0rBEhUpVj

Stretched molecule puts a new spin on electrons

Physicists in the US have invented a way of measuring the magnetic properties of a single molecule as it is being stretched. The technique provides a

new approach for studying quantum chemistry and how the spin of an electron affects its passage through tiny structures.

The technique could one day even be adapted for use in spintronic devices, which use the spin of the electron to process and store information.

Physicists build quantum amplifier with single artificial atom

By demonstrating how a single artificial atom can be used to amplify electromagnetic waves, physicists from Japan are opening up new possibilities for quantum amplifiers, which can be used in a variety of electronic and optical applications.

Physicsts reveal how to cope with 'frustration'

For most people, frustration is a condition to be avoided. But for scientists studying certain "frustrated" ensembles of interacting components -that is, those which cannot settle into a state that minimizes each interaction-

 it may be the key to understanding a host of puzzling phenomena that affect systems from neural networks and social structures to protein folding and magnetism.

Electrical properties of glass at the nanoscale lead to a pump the size of a red blood cell

Researchers have devised a way to fabricate tiny electrodes from glass, harnessing a phenomenon by which nanoscale glass walls can be transformed from insulators to conductors and back again. At larger scales, that phenomenon, known as  dielectric breakdown , leads to excess heating and structural damage,  but at the nanoscale the process appears to be harmless and  reversible.

Vitaly Lazarevich Ginzburg

Vitaly Lazarevich Ginzburg, who made important contributions in many fields of theoretical physics, passed away on 8 November 2009 in Moscow; he had suffered for several years from a blood disease.

Graphene transistor could advance nanodevices

For years, scientists and researchers have been looking into the properties of carbon nanotubes and graphene for use in nanoelectronics.  There is no real mass application of devices based on graphene and carbon nanotubes , Zhenxing Wang tells PhysOrg.com.  This is really an opportunity for them to show their capabilities .

Appl. Phys. Lett. 96, 173104 ( 2010 )

Unraveling the physics of DNA's double helix

 The stability of DNA is so fundamental to life that it's important to understand all factors , said Piotr Marszalek, a professor of mechanical engineering and materials sciences at Duke.  If you want to create accurate models of DNA to study its interaction with proteins or drugs, for example,  you need to understand the basic physics of the molecule . For that, you need solid measurements of the forces that stabilize DNA .

DNA construction kit for nanoengines

For a rotaxane molecule consists essentially of an axle and a ring, or hoop, threaded over it. To prevent the hoop from slipping off the axle, bulky  stoppers  are placed at each end. These, in turn, consist of intertwined rings. The whole construction looks rather like a dumbbell with a hoop around its handle ( see diagram ).

Laser technology provides a quantum leap (La tecnología láser da un salto cuántico)

En la Universidad de Innsbruck ( Austria ), un equipo de investigación financiado con fondos comunitarios ha creado un láser de átomo único que se rige por el mismo principio que los láseres clásicos pero que además presenta propiedades cuánticas en sus interacciones entre átomos y fotones. Los resultados de su investigación, publicados en la revista Nature Physics, ampliarán el conocimiento que se posee de las propiedades de los láseres y podrán utilizarse para medir composiciones de oligoelementos gaseosos e isótopos de carbono en el aire y el suelo.

At the University of Innsbruck ( Austria ), a team of private funded research has created a single atom laser which is governed by the same principle as lasers but also presents classical quantum properties in interactions between atoms and photons. The results of their research, published in the journal Nature Physics, expand the knowledge of the lasers properties and may be used to measure gas compositions of trace elements and isotopes of carbon in the air and soil.

Viajar a la velocidad de la luz mataría en pocos segundos

Malas noticias para todos los que soñábamos con recorrer la galaxia a velocidades relativísticas. Según parece, al desplazarnos a velocidades cercanas a la de la luz, los escasos átomos de hidrógeno que existen en el espacio  vacío  nos golpearían tan duro como las partículas aceleradas por el Gran Colisionador de Hadrones ( LHC ). Si los científicos de la Universidad Johns Hopkins están en lo cierto,  esos pequeños átomos nos freirían en pocos segundos .

Bad news for all those who dreamed of exploring the galaxy at relativistic speeds. Apparently, the motion at speeds approaching that of light, the few hydrogen atoms that exist in the  vacuum  would hit us as hard as particles accelerated by the Large Hadron Collider ( LHC ). If scientists at Johns Hopkins University are right,  these little atoms will fry us in a few seconds .

Charging Ahead: Carbon Nanotubes Could Hold Long-Sought Battery Technology Breakthrough

With battery technology advances long overdue, researchers are racing to develop more efficient ways to store power. One hopeful option is in the use of carbon nanotubes,  which can store much more electricity by weight than lithium-ion batteries while keeping their charge and remain durable for far longer .