Relational quantum mechanics suggests physics might be a science of perceptions, not observer-independent reality.
- By Bernardo Kastrup on May 24, 2019
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Category: quantum physics – Page 903
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.
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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.
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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.
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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…
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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.
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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.
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