Quantum Physics – Lifeboat News: The Blog

Jul 18
2016

Research breakthrough towards ‘practical’ quantum computing future

This truly makes QC more practical on many fronts. First, no need for QC to reside in an “icebox” room/ environment. Second, with the recent findings on making quantum computing scalable; we now have a method in place to not make QC devices over heat as well. So, again another major step forward by Sydney and their partners in Switzerland and Germany.

http://www.itwire.com/development/73884-research-breakthroug…uture.html

A group of international researchers, including a leading research from the University of Sydney, has made a breakthrough discovery, making a conducting carbon material that they demonstrated could be used to perform quantum computing at room temperature, rather than near absolute zero (−273°C).

The collaboration involved a team co-led by Dr Mohammad Choucair – who recently finished a University of Sydney research fellowship in the university’s School of Chemistry – and collaborators in Switzerland and Germany.

The material produced by the researchers is simply created by burning naphthalene, the ashes form the carbon material.

Jul 18
2016

Organisms might be quantum machines

Few of us really understand the weird world of quantum physics – but our bodies might take advantage of quantum properties.

Jul 18
2016

Quantum Computing With Mothballs: Scientists Find A Way To Stabilize Electron Spins At Room Temperature

A team of researchers has overcome a key challenge — how to build a quantum computer that is capable of functioning at room temperature.

Jul 18
2016

Can we find a quantum-resistant algorithm before it’s too late?

The warning from QuintessenceLabs’ CTO John Leisoboer is stark. “When sufficiently powerful quantum computers become generally available,” he says, “it’s guaranteed to break all existing cryptographic systems that we know of.”

In other words, he adds, “Everything that we’re doing today will be broken.”

It’s a sentiment echoed by Google’s Chrome security software engineer Matt Braithwaite who wrote in a blog post earlier this month that “a hypothetical, future quantum computer would be able to retrospectively decrypt any internet communication that was recorded today”.

Jul 17
2016

Primitive Quantum Computers Are Already Outperforming Current Machines

A team has used simple quantum processors to run “quantum walk” algorithms, showing that even primitive quantum computers can outperform the classical variety in certain scenarios—and suggesting that the age of quantum computing may be closer than we imagined.

By now, most readers of Futurism are probably pretty well acquainted with the concept (and fantastic promise) of quantum computing.

For those who aren’t, the idea is fairly (!) simple: Quantum computers exploit three very unusual features that operate at the quantum scale—that electrons can be both particles and waves, that objects can be in many places at once, and they can maintain an instantaneous connection even when separated by vast distances (a property called “entanglement”).

Jul 16
2016

Gravity doesn’t care about quantum spin

Physics, as you may have read before, is based around two wildly successful theories. On the grand scale, galaxies, planets, and all the other big stuff dance to the tune of gravity. But, like your teenage daughter, all the little stuff stares in bewildered embarrassment at gravity’s dancing. Quantum mechanics is the only beat the little stuff is willing get down to. Unlike teenage rebellion, though, no one claims to understand what keeps relativity and quantum mechanics from getting along.

Because we refuse to believe that these two theories are separate, physicists are constantly trying to find a way to fit them together. Part-in-parcel with creating a unifying model is finding evidence of a connection between the gravity and quantum mechanics. For example, showing that the gravitational force experienced by a particle depended on the particle’s internal quantum state would be a great sign of a deeper connection between the two theories. The latest attempt to show this uses a new way to look for coupling between gravity and the quantum property called spin.

I’m free, free fallin’

One of the cornerstones of general relativity is that objects move in straight lines through a curved spacetime. So, if two objects have identical masses and are in free fall, they should follow identical trajectories. And this is what we have observed since the time of Galileo (although I seem to recall that Galileo’s public experiment came to an embarrassing end due to differences in air resistance).

Jul 16
2016

Optical Magnetic Field Sensor can Detect Ultra-Small Magnetic Fields

Small magnetic fields from the human body can usually only be picked up by very sensitive superconducting magnetic field sensors that have to be cooled by liquid helium to near absolute zero (which is minus 273 degrees Celsius). But now researchers from the Niels Bohr Institute at the University of Copenhagen have developed a much cheaper and more practical optical magnetic field sensor that even works at room temperature or at body temperature.

“The optical magnetic field sensor is based on a gas of caesium atoms in a small glass container. Each caesium atom is equivalent to a small bar magnet, which is affected by external magnetic fields. The atoms and thus the magnetic field are picked up using laser light. The method is based on quantum optics and atomic physics and can be used to measure extremely small magnetic fields,” explains Kasper Jensen, assistant professor in the Center for Quantum Optics, Quantop at the Niels Bohr Institute at the University of Copenhagen.

Ultra sensitive magnetic field sensor.

Jul 15
2016

Images made of relativistic electrons trapped in graphene quantum dots

(Phys.org)—A team of researchers with the University of California, MIT, Lawrence Berkeley National Laboratory and the National Institute for Materials Science in Japan has created images of relativistic electrons trapped in graphene quantum dots. In their paper published in the journal Nature Physics the team describes how they achieved this feat and where they plan to take their work in the future.

As the many unique properties of graphene continue to unfold, scientists seek new ways to harness and eventually make use of them. One such use might be to control electrons to allow their use in nano-scaled devices, which could also inadvertently lead to a deeper understanding of Dirac fermions. In this new effort, the researchers have made progress in that area by devising a means for capturing and holding electrons and for creating images of the result.

Obtaining images of electron waveforms has thus far been particularly difficult—virtually all existing methods have resulted in too many defects. To get around such problems, the researchers took another approach to capturing the electrons. They first created circular p-n junctions by sending voltage through the tip of a scanning tunneling microscope down to a graphene sample below. At the same time, they also applied voltage to a slab of silicon underneath the piece of graphene, which was kept separated by a layer of silicon-oxide and a flake of boron nitride. Doing so caused defects in the boron nitride to ionize, resulting in charges migrating to the graphene.

Jul 15
2016

Optical magnetic field sensor can detect signals from the nervous system

Quantum physics: The human body is controlled by electrical impulses in, for example, the brain, the heart and nervous system. These electrical signals create tiny magnetic fields, which doctors could use to diagnose various diseases, for example diseases of the brain or heart problems in young foetuses. Researchers from the Niels Bohr Institute have now succeeded in developing a method for extremely precise measurements of such ultra-small magnetic fields with an optical magnetic field sensor. The results are published in the scientific journal, Scientific Reports.

Assistant Professor Kasper Jensen in the Quantop research group’s laboratories at the Niels Bohr Institute where the experiments are carried out. (Photo: Ola Jakup Joensen)

Jul 15
2016

Scientists: Quantum Fingerprinting May Be Better Than Classical Limit for Communication

Scientists found that quantum fingerprinting protocol can surpass the classical limit for solving communication complexity problems.

A new study has experimentally demonstrated a quantum fingerprinting protocol and shown that it can surpass the classical limit for solving communication complexity problems. Scientists say that in these problems, two parties each have a message, and they both share some of their message with a referee, who has to decide whether the two messages are the same or not. The classical limit requires that a minimum amount of information must be transmitted between each party and the referee in order for the referee to make this decision.

Researchers found that the best communication complexity protocols require transmission of data that is two orders of magnitude larger than the classical limit.