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Researchers successfully sent a simulated elementary particle back in time

The results are fascinating and spur the imagination, but don’t start investing in flux capacitors yet. This experiment also shows us that sending even a simulated particle back in time requires serious outside manipulation. To create such an external force to manipulate even one physical particle’s quantum waves is well beyond our abilities.

“We demonstrate that time-reversing even ONE quantum particle is an unsurmountable task for nature alone,” study author Vinokur wrote to the New York Times in an email [emphasis original]. “The system comprising two particles is even more irreversible, let alone the eggs — comprising billions of particles — we break to prepare an omelet.”

A press release from the Department of Energy notes that for the “timeline required for [an external force] to spontaneously appear and properly manipulate the quantum waves” to appear in nature and unscramble an egg “would extend longer than that of the universe itself.” In other words, this technology remains bound to quantum computation. Subatomic spas that literally turn back the clock aren’t happening.

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Physicists invent flux capacitor, break time-reversal symmetry

In the popular movie franchise “Back to the Future”, an eccentric scientist creates a time machine that runs on a flux capacitor.

Now a group of actual physicists from Australia and Switzerland have proposed a device which uses the tunneling of around a capacitor, breaking time-reversal symmetry.

The research, published this week in Physical Review Letters, proposes a of electronic circulators, which are devices that control the direction in which microwave signals move.

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Computing faster with quasi-particles

Majorana particles are very peculiar members of the family of elementary particles. First predicted in 1937 by the Italian physicist Ettore Majorana, these particles belong to the group of so-called fermions, a group that also includes electrons, neutrons and protons. Majorana fermions are electrically neutral and also their own anti-particles. These exotic particles can, for example, emerge as quasi-particles in topological superconductors and represent ideal building blocks for topological quantum computers.

Going to two dimensions

On the road to such topological quantum computers based on Majorana quasi-particles, physicists from the University of W\xFCrzburg together with colleagues from Harvard University (USA) have made an important step: Whereas previous experiments in this field have mostly focused on one-dimensional systems, the teams from W\xFCrzburg and Harvard have succeeded in going to two-dimensional systems.

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Discrete energy levels without confinement – a new quantum trick

Nanostructures can be designed such a way that the quantum confinement allows only certain electron energy levels. Researchers from IMDEA Nanociencia, UAM and ICMM-CSIC have, for the first time, observed a discrete pattern of electron energies in an unconfined system, which could lead to new ways of modifying the surface properties of materials.

A research group from IMDEA Nanoscience and Universidad Autónoma de Madrid has found for the first time experimental evidence that one-dimensional lattices with nanoscale periodicity can interact with the electrons from a bidimensional gas by spatially separating their different wavelengths by means of a physical phenomenon known as Bragg diffraction. This phenomenon is well-known for wave propagation in general and is responsible for the iridescent color observed upon illumination of a CD surface. Due to the wave-particle duality proposed by De Broglie in 1924, electrons also present a wave-like behavior and, thus, diffraction phenomena. Actually, the observation that low-energy free electrons undergo diffraction processes upon interaction with well-ordered atomic lattices on solid surfaces was the first experimental confirmation of the wave-particle duality.

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28 years old and closer than ever to the solving of the mistery of the Majorana particles

Gazibegović, Ph.D. candidate in the group of prof. Erik Bakkers at the department of Applied Physics, developed a device made of ultrathin networks of nanowires in the shape of “hashtags.” This device allows pairs of Majorana particles to exchange position and keep track of the changes occurred, in a phenomenon known as “braiding.” This event is considered as a striking proof of the existence of Majorana particles, and it represents a crucial step towards their use as building blocks for the development of quantum computers. With two Nature publications in her pocket, Gazibegović is ready to defend her Ph.D. thesis on May 10.

In 1937, the Italian theoretical physicist Ettore Majorana hypothesized the existence of a unique particle that is its own antiparticle. This particle, also referred to as a “Majorana fermion,” can also exist as a “quasiparticle,” a collective phenomenon that behaves like an individual particle, as in waves forming on the water. The water itself stays in the same place, but the wave can “travel” on the surface, as if it were a single particle in movement. For many years, physicists have been trying to find the Majorana particle without success. Yet, in the last decade, scientists from Eindhoven University of Technology have taken great leap forwards in proving the existence of Majorana particles, also thanks to the research of Gazibegović and her collaborations with the University of Delft, Philips Research and the University of California – Santa Barbara.

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