FBD
10-07-2014, 08:31 PM
http://phys.org/news/2014-10-majorana-fermion-physicists-elusive-particle.html
Majorana fermion: Physicists observe elusive particle that is its own antiparticle
http://cdn.phys.org/newman/gfx/news/2014/princetonsci.png
rinceton University scientists have observed an exotic particle that behaves simultaneously like matter and antimatter, a feat of math and engineering that could yield powerful computers based on quantum mechanics.
Using a two-story-tall microscope floating in an ultralow-vibration lab at Princeton's Jadwin Hall, the scientists captured a glowing image of a particle known as a "Majorana fermion" perched at the end of an atomically thin wire—just where it had been predicted to be after decades of study and calculation dating back to the 1930s.
"This is the most direct way of looking for the Majorana fermion as it is expected to emerge at the edge of certain materials," said Ali Yazdani, a professor of physics who led the research team. "If you want to find this particle within a material you have to use such a microscope, which allows you to see where it actually is."
The hunt for the Majorana fermion began in the earliest days of quantum theory when physicists first realized that their equations implied the existence of "antimatter" counterparts to commonly known particles such as electrons. In 1937, Italian physicist Ettore Majorana predicted that a single, stable particle could be both matter and antimatter. Although many forms of antimatter have since been observed, the Majorana combination remained elusive.
In addition to its implications for fundamental physics, the finding offers scientists a potentially major advance in the pursuit of quantum computing. In quantum computing, electrons are coaxed into representing not only the ones and zeroes of conventional computers but also a strange quantum state that is both a one and a zero. This anomalous property, called quantum superposition, offers vast opportunities for solving previously incalculable systems, but is notoriously prone to collapsing into conventional behavior due to interactions with nearby material.
Despite combining qualities usually thought to annihilate each other—matter and antimatter—the Majorana fermion is surprisingly stable; rather than being destructive, the conflicting properties render the particle neutral so that it interacts very weakly with its environment. This aloofness has spurred scientists to search for ways to engineer the Majorana into materials, which could provide a much more stable way of encoding quantum information, and thus a new basis for quantum computing.
A team led by Yazdani and including colleagues at Princeton and at the University of Texas-Austin published their results in the Oct. 2 issue of the journal Science.
Yazdani noted that the observation of the Majorana fermion bound within a material is different for physicists than the much publicized discovery of particles, such as the Higgs boson, in a vacuum in giant accelerators. In such experiments, scientists collide particles at high speeds, producing a shower of free and ephemeral components. In materials, by contrast, the existence of a particle depends on—or emerges from—the collective properties of atoms and forces surrounding it.
By controlling these interactions, the researchers said, their Majoranas appeared "clean and removed from any spurious particles," which would be unavoidable in high-energy accelerator experiments. "This is more exciting and can actually be practically beneficial," Yazdani said, "because it allows scientists to manipulate exotic particles for potential applications, such as quantum computing."
In addition to their potential practical uses, the pursuit of Majoranas has broad implications for other areas of physics. Scientists believe, for example, that another sub-atomic particle called neutrinos, which also interact very weakly and are very hard to detect, could be a type of Majorana—a neutrino and anti-neutrino being the same particle. In addition, scientists regard Majoranas as possible candidates for dark matter, the mysterious substance that is thought to account for most matter in the universe, but which has not been directly observed because it also does not directly interact with other particles.
More at Link..vid included.
Majorana fermion: Physicists observe elusive particle that is its own antiparticle
http://cdn.phys.org/newman/gfx/news/2014/princetonsci.png
rinceton University scientists have observed an exotic particle that behaves simultaneously like matter and antimatter, a feat of math and engineering that could yield powerful computers based on quantum mechanics.
Using a two-story-tall microscope floating in an ultralow-vibration lab at Princeton's Jadwin Hall, the scientists captured a glowing image of a particle known as a "Majorana fermion" perched at the end of an atomically thin wire—just where it had been predicted to be after decades of study and calculation dating back to the 1930s.
"This is the most direct way of looking for the Majorana fermion as it is expected to emerge at the edge of certain materials," said Ali Yazdani, a professor of physics who led the research team. "If you want to find this particle within a material you have to use such a microscope, which allows you to see where it actually is."
The hunt for the Majorana fermion began in the earliest days of quantum theory when physicists first realized that their equations implied the existence of "antimatter" counterparts to commonly known particles such as electrons. In 1937, Italian physicist Ettore Majorana predicted that a single, stable particle could be both matter and antimatter. Although many forms of antimatter have since been observed, the Majorana combination remained elusive.
In addition to its implications for fundamental physics, the finding offers scientists a potentially major advance in the pursuit of quantum computing. In quantum computing, electrons are coaxed into representing not only the ones and zeroes of conventional computers but also a strange quantum state that is both a one and a zero. This anomalous property, called quantum superposition, offers vast opportunities for solving previously incalculable systems, but is notoriously prone to collapsing into conventional behavior due to interactions with nearby material.
Despite combining qualities usually thought to annihilate each other—matter and antimatter—the Majorana fermion is surprisingly stable; rather than being destructive, the conflicting properties render the particle neutral so that it interacts very weakly with its environment. This aloofness has spurred scientists to search for ways to engineer the Majorana into materials, which could provide a much more stable way of encoding quantum information, and thus a new basis for quantum computing.
A team led by Yazdani and including colleagues at Princeton and at the University of Texas-Austin published their results in the Oct. 2 issue of the journal Science.
Yazdani noted that the observation of the Majorana fermion bound within a material is different for physicists than the much publicized discovery of particles, such as the Higgs boson, in a vacuum in giant accelerators. In such experiments, scientists collide particles at high speeds, producing a shower of free and ephemeral components. In materials, by contrast, the existence of a particle depends on—or emerges from—the collective properties of atoms and forces surrounding it.
By controlling these interactions, the researchers said, their Majoranas appeared "clean and removed from any spurious particles," which would be unavoidable in high-energy accelerator experiments. "This is more exciting and can actually be practically beneficial," Yazdani said, "because it allows scientists to manipulate exotic particles for potential applications, such as quantum computing."
In addition to their potential practical uses, the pursuit of Majoranas has broad implications for other areas of physics. Scientists believe, for example, that another sub-atomic particle called neutrinos, which also interact very weakly and are very hard to detect, could be a type of Majorana—a neutrino and anti-neutrino being the same particle. In addition, scientists regard Majoranas as possible candidates for dark matter, the mysterious substance that is thought to account for most matter in the universe, but which has not been directly observed because it also does not directly interact with other particles.
More at Link..vid included.