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A Monash University study revealing new spin textures in pyrite could unlock these materials’ potential in future spintronics devices.

The study of pyrite-type materials provides new insights and opportunities for selective spin control in topological spintronics devices.

Oxford University researchers have, for the first time, generated a massive 10 billion entangled bits in silicon, taking an important step towards a real world quantum computer.

The researchers cooled a piece of phosphorus-doped silicon to within one degree of absolute zero and applied a magnetic field. This process lined up the spins of one electron per phosphorus atom. Then the scientists used carefully timed radio pulses to nudge the nuclei and electrons into an entangled state. Across the silicon crystal, this produced billions of entangled pairs.

Stephanie Simmons, researcher and lead author on the paper Entanglement in a solid-state spin ensemble — published in Nature, says that quantum computers really start to give classical computers a run for their money at a few dozen qubits, but her team is working to skip that stage altogether by going directly from a two-qubit system to one with 10 billion.

The XENON experiment recently made a breakthrough in their hunt for dark matter, observing the most rare decay process in the Universe that involves neutrinos.

A team of researchers at the University of California, Berkeley, has found a new way to measure gravity—by noting differences in atoms in a supposition state, suspended in the air by lasers. In their paper published in the journal Science, the group describes their new technique and explain why they believe it will be more useful than traditional methods.

Currently, the standard way to conduct gravity experiments is to drop things down shielded tubes and measure them as they whiz by instruments. In addition to giving researchers a very brief glimpse of gravitational interactions, such methods often fall prey to inadvertent stray magnetic fields. In this new effort, the researchers have found a way to measure gravity that does not involve dropping objects at all.

The new approach involved releasing a cloud of cesium atoms into the air in a small chamber and then using flashing lights to split several of them into a superposition state. Once split, lasers were used to keep all the atoms in fixed positions with one of each pair raised slightly higher than its mate. The team then measured each atom’s wave particle duality, which is impacted by gravity. By measuring the difference in duality between the paired atoms (because of the difference in their distances from Earth), the researchers were able to come up with a measurement for gravity.

A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.

In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very bright, and the photons delivered must have sufficiently high energy. This combination of properties has been sought in laboratories around the world for the past 15 years. Physicists at the Laboratory for Attosecond Physics (LAP), a joint venture between the Ludwig-Maximilians-Universität Munich (LMU) and the Max Planck Institute of Quantum Optics (MPQ), have now succeeded in meeting the conditions necessary to achieve this goal. In their latest experiments, they have been able to observe the non-linear interaction of an attosecond pulse with electrons in one of the inner orbital shells around the atomic nucleus. In this context, the term ‘non-linear’ indicates that the interaction involves more than one photon (in this particular case two are involved).

There may be a way of sneaking a peak at Schrödinger’s cat — the famous feline-based thought experiment that describes the mysterious behavior of subatomic particles — without permanently killing the (hypothetical) animal.

Circa 2016

Laser physicists in Munich have measured a photoionization — in which an electron exits a helium atom after excitation by light — for the first time with zeptosecond precision. A zeptosecond is a trillionth of a billionth of a second (10^−21 seconds). This is the greatest accuracy of time determination ever achieved, as well as the first absolute determination of the timescale of photoionization.

If light hits the two electrons of a helium atom, one must be incredibly fast to observe what occurs. Besides the ultra-short periods in which changes take place, quantum mechanics also comes into play. Laser physicists at the Max Planck Institute of Quantum Optics (MPQ), the Technical University of Munich (TUM) and the Ludwig Maximilians University (LMU) Munich have now measured such an event for the first time with zeptosecond precision.

Continue reading “Entering the field of zeptosecond measurement” »

In 1884, a schoolmaster and theologian named Edwin Abbott wrote a novella called Flatland, which tells the story of a world populated by sentient two-dimensional shapes. While intended as a satire of rigid Victorian social norms, Flatland has long fascinated mathematicians and physicists and served as the setting for many a thought experiment.

One such thought experiment: How can light be controlled in two dimensions?

When a wave of light is confined on a two-dimensional plane by certain materials, it becomes something known as a polariton—a particle that blurs the distinction between light and matter. Polaritons have exciting implications for the future of optical circuits because, unlike electronic integrated circuits, integrated optics is difficult to miniaturize with commonly used materials. Polaritons allow light to be tightly confined to the nanoscale, even potentially to the thickness of a few atoms.

The second objective is propulsion. This is achieved by emitting pulsed cathode rays out of one end of the craft tuned to the rate of change of jet stream particles surrounding the bubble. At the other end of the craft, cations are emitted at the same rate of change. This creates a push/pull effect, doubling the ship’s acceleration and velocity capabilities.