Quantum Physics – Lifeboat News: The Blog

May 24
2019

Study investigates how spin-orbit interaction protects Majorana nanowires

Researchers at Delft University of Technology have recently carried out a study investigating spin-orbit interaction in Majorana nanowires. Their study, published in Physical Review Letters, is the first to clearly show the mechanism that enables the creation of the elusive Majorana particle, which could become the building block of a more stable type of quantum computer.

“Our research is aimed at experimental verification of the theoretically proposed Majorana zero-mode,” Jouri Bommer, one of the researchers who carried out the study, told Phys.org via email. “This particle, which is its own antiparticle, is of particular interest, because it is predicted to be useful for developing a topological quantum computer.”

Quantum computing is a promising area of computer science that explores the use of quantum-mechanical phenomena and quantum states to store information and solve computational problems. In the future, quantum computers could tackle problems that traditional computing methods are unable to solve, for instance enabling the computational and deterministic design of new drugs and molecules.

May 24
2019

The Universe as Cosmic Dashboard

Relational quantum mechanics suggests physics might be a science of perceptions, not observer-independent reality.

By Bernardo Kastrup on May 24, 2019

May 24
2019

Quantum computing boost from vapour stabilising technique

A technique to stabilise alkali metal vapour density using gold nanoparticles, so electrons can be accessed for applications including quantum computing, atom cooling and precision measurements, has been patented by scientists at the University of Bath.

Alkali metal vapours, including lithium, sodium, potassium, rubidium and caesium, allow scientists to access individual electrons, due to the presence of a single electron in the outer ‘shell’ of alkali metals.

This has great potential for a range of applications, including logic operations, storage and sensing in quantum computing, as well as in ultra-precise time measurements with atomic clocks, or in medical diagnostics including cardiograms and encephalograms.

May 23
2019

New collider concept would take quantum theories to an extreme

A new idea for smashing beams of elementary particles into one another could reveal how light and matter interact under extreme conditions that may exist on the surfaces of exotic astrophysical objects, in powerful cosmic light bursts and star explosions, in next-generation particle colliders and in hot, dense fusion plasma.

Most such interactions in nature are very successfully described by a theory known as quantum electrodynamics (QED). However, the current form of the theory doesn’t help predict phenomena in extremely large electromagnetic fields. In a recent paper in Physical Review Letters, researchers from the Department of Energy’s SLAC National Accelerator Laboratory and their colleagues have suggested a new particle collider concept that would allow us to study these extreme effects.

Extreme fields sap energy from colliding particle beams—an unwanted loss that is typically mitigated by bundling particles into relatively long, flat bunches and keeping the electromagnetic field strength in check. Instead, the new study suggests making particle bunches so short that they wouldn’t have enough time to lose energy. Such a collider would provide an opportunity to study intriguing effects associated with extreme fields, including the collision of photons emerging from the particle beams.

May 23
2019

Physicists Created Quantum Structures That May Have Birthed Dark Matter

Some cosmologists have predicted the existence of “walls bounded by strings” in the aftermath of the Big Bang, and now a team of physicists have created these quantum structures on Earth for the first time.

May 23
2019

The geometry of an electron determined for the first time

Physicists at the University of Basel have shown for the first time how a single electron looks in an artificial atom. A newly developed method enables them to show the probability of an electron being present in a space. This allows improved control of electron spins, which could serve as the smallest information unit in a future quantum computer. The experiments were published in Physical Review Letters and the related theory in Physical Review B.

The spin of an electron is a promising candidate for use as the smallest information unit (qubit) of a quantum computer. Controlling and switching this spin or coupling it with other spins is a challenge on which numerous research groups worldwide are working. The stability of a single spin and the entanglement of various spins depends, among other things, on the geometry of the electrons—which previously had been impossible to determine experimentally.

May 22
2019

Synopsis: How High Schools Teach Quantum Physics

Researchers analyze secondary school curricula from 15 countries, revealing common themes and a need for emphasizing process over facts.

May 22
2019

Physicists propose a second level of quantization for quantum Shannon theory

Information theory, which was developed by Claude Shannon starting in the late 1940s, deals with questions such as how quickly information can be sent over a noisy communications channel. Both the information carriers (e.g., photons) and the channel (e.g., optical fiber cable) are assumed to be clas…

May 21
2019

There’s a Brand-New Kilogram, And It’s Based on Quantum Physics

The kilogram isn’t a thing anymore. Instead, it’s an abstract idea about light and energy.

As of today (May 20), physicists have replaced the old kilogram — a 130-year-old, platinum-iridium cylinder weighing 2.2 pounds (1 kilogram) sitting in a room in France — with an abstract, unchanging measurement based on quadrillions of light particles and Planck’s constant (a fundamental feature of our universe).

In one sense, this is a grand (and surprisingly difficult) achievement. The kilogram is fixed forever now. It can’t change over time as the cylinder loses an atom here or an atom there. That means humans could communicate this unit of mass, in terms of raw science, to space aliens. The kilogram is now a simple truth, an idea that can be carried anywhere in the universe without bothering to bring a cylinder with you.

May 21
2019

Advance to Controlling one to a Few Hundred Atoms at Microsecond Timescales Using AI Control of Electron Beams

The work should lead to control one to a few hundred atoms at microsecond timescales using AI control of electron beams. The computational/analytical framework developed in this work are general and can further help develop techniques for controlling single-atom dynamics in 3D materials, and ultimately, upscaling manipulations of multiple atoms to assemble 1 to 1000 atoms with high speed and efficacy.

Scientists at MIT, the University of Vienna, and several other institutions have taken a step toward developing a method that can reposition atoms with a highly focused electron beam and control their exact location and bonding orientation. The finding could ultimately lead to new ways of making quantum computing devices or sensors, and usher in a new age of “atomic engineering,” they say.

This could help make quantum sensors and computers.