Tag Archives: quantum

We’re 50 km closer to quantum internet

A team of researchers based in Innsbruck reports sending light entangled with quantum information over a 50-kilometer-long stretch of optic fiber.

Image credits Joshua Kimsey.

The study comes as a collaboration between members at the Department of Experimental Physics at the University of Innsbruck and at the Institute of Quantum Optics and Quantum Information of the Austrian Academy of Sciences. They report setting the longest record for the transfer of quantum entanglement between matter and light.

Such results pave the way for long-range quantum communication, which would enable transfer between different cities, for example. Effectively, the early stages of quantum bit Internet.

Lasers and crystals

“[50 km] is two orders of magnitude further than was previously possible and is a practical distance to start building inter-city quantum networks,” says Ben Lanyon, the Ph.D. and experimental physicist at the Austrian Academy of Sciences who led the research.

One of the most appealing prospects of a quantum internet is that it should be completely tap-proof. Information in such a network is encrypted and unbreakable, and any interference with the signal readily apparent.

However, quantum information cannot be copied, so it wouldn’t work through your router.

Such information needs to be carried by entangled particles. So the team took a calcium ion, secured it in an ion trap, and blasted it with lasers. This step both ‘wrote’ the information into the ion as a quantum state and made it emit a photon (to ‘glow’, basically). Then, this photon needed to be amplified to be sent down the optic fiber.

“The photon emitted by the calcium ion has a wavelength of 854 nanometers and is quickly absorbed by the optical fiber,” says Lanyon.

The researchers sent the photon through a crystal illuminated by a strong laser to boost it up to a wavelength of 1550 nanometers. The calcium atom and light particle were still entangled even after the conversion and a 50-kilometer journey through the optic cable.

In the future, the team wants to double the distance such a particle can travel to 100 km of optic fiber, potentially enabling connections between cities. Only a handful of trapped ion-systems would be required to maintain a quantum internet link between Innsbruck and Vienna (387km/240mi), for example.

The paper “Light-matter entanglement over 50 km of optical fibre” has been published in the journal npj Quantum Information.

Scientists eavesdrop on sound particles with quantum microphone

Researchers have developed a microphone so sensitive it’s capable of picking up individual particles of sound.

Artist’s impression of an array of nanomechanical resonators designed to generate and trap sound particles, or phonons. Image credits: Wentao Jiang.

OK, we knew light has particles, and gravity has particles. Now even sound has particles? Well, not quite. A phonon is what’s called a quasiparticle — basically, an emergent phenomenon that occurs when a microscopically complicated system behaves as if it were a particle.

But although they’re not real particles (what’s real in the quantum world anyway?), phonons have a lot in common with photons, the carriers of light: they’re quantized. Being quantized is the backbone of all quantum particles and as strange as that may sound, it actually means something very simple: it means that they can only carry some types of energy.

Let’s say we have a minimum possible energy level — a particle can only have exact multiples of that ammount. If the minimum level is “1”, it can only have 1, 2, 3, 4… and so on — not 1.5, or any value in between. Think of it as the rungs on a ladder of energy, with nothing in between.

Since photons also have this characteristic to them, it means that a quantum level, it gets pretty weird.

“Sound has this granularity that we don’t normally experience,” said study leader Amir Safavi-Naeini, from Stanford. “Sound, at the quantum level, crackles.”

Although phonons have been described by Albert Einstein, researchers have only been able to measure phonon states in engineered structures — until now.

The problem with building a phonon microphone is the scale at which you have to build it.

“One phonon corresponds to an energy ten trillion trillion times smaller than the energy required to keep a lightbulb on for one second,” said graduate student Patricio Arrangoiz-Arriola, a co-first author of the study.

The team captured the peaks of different phonon energy levels in the qubit spectrum for the first time. Image credits: Arrangoiz-Arriola, Patricio, Wollack, et al, 2019.

A regular microphone works thanks to an internal membrane that vibrates when hit by sound waves. This physical movement is converted into a measurable voltage. However, if you tried to make a quantum microphone this way, it wouldn’t work. According to Heisenberg’s uncertainty principle, a quantum object’s position can’t be precisely known without changing it. So if you tried to measure the number of phonons, the measurement itself would mask their energy levels. So the researchers decided to measure this latter property.

The quantum microphone consists of a series of supercooled nanomechanical resonators, so small that they are visible only through an electron microscope. The resonators are connected to a superconducting circuit which contains electron pairs that move around without resistance. The circuit forms a qubit — a system that can exist in two states at once and has a natural frequency, which can be read electronically.

“The resonators are formed from periodic structures that act like mirrors for sound. By introducing a defect into these artificial lattices, we can trap the phonons in the middle of the structures,” Arrangoiz-Arriola said.

While the system is extremely complex and difficult to handle, the results are also worth it. Mastering the ability to precisely generate and detect phonons could help pave the way for new kinds of quantum devices that are able to store and retrieve information encoded as particles of sound or that can convert seamlessly between optical and mechanical signals.

Safavi-Naeini concludes:

“Right now, people are using photons to encode these states. We want to use phonons, which brings with it a lot of advantages.

“Our device is an important step toward making a ‘mechanical quantum mechanical’ computer.”

The study was published in the journal Nature.

For the first time, researchers show what an electron actually looks like

 

An electron trapped in a quantum dot. Image credits: University of Basel.

We first learn in school that electrons, like tiny planetary satellites, spin around the atomic nucleus. Then, more advanced physics tells us that the electrons form a sort of cloud which, depending on how you look at it, behaves both as a particle and as a wave.

As far as we know, electrons don’t really have a shape per se, their distribution is most commonly discussed in terms of orbitals — a mathematical function that describes the wave-like behavior of an electron or a group of several electrons. In quantum mechanics as well as classical chemistry, the orbital is rather a probability distribution than an orbit — but for the sake of simplified visualization, we still talk about electron orbits. However, this situation wasn’t satisfactory for all scientists.

A team of researchers from the University of Basel have used an artificial atom, a system also called a “quantum dot.” Within a quantum dot, an electron is held in place by electric fields, basically acting as a trap — though one which is about 1000 times larger than a natural atom. However, because the trapped electrons behave similarly to electrons bound to an atom, quantum dots are also known as “artificial atoms.” These tiny crystals are also used in QLED televisions, among others technologies.

Image credits: Camenzind et al., PRL, 2019.

After the system was devised and constructed, researchers used spectroscopic measurements to determine the energy levels in the quantum dot, noting the varying magnetic fields’ strength and orientation, which was influenced by the electron’s movement. This data was then introduced into a theoretical model, which enabled the researchers to calculate the electron’s wave function with a sub-nanometer scale.

“To put it simply, we can use this method to show what an electron looks like for the first time,” explains Daniel Loss from the Department of Physics and the Swiss Nanoscience Institute at the University of Basel.

“We are able to not only map the shape and orientation of the electron, but also control the wave function according to the configuration of the applied electric fields. This gives us the opportunity to optimize control of the spins in a very targeted manner,” adds Dominik Zumbühl, also one of the study authors.

They then took things one step further: by carefully arranging an electric field, they were able to direct the electron’s movement in a precise matter.

This is important not only as a theoretical advancement, but could also have important applications — not only in fancy televisions, but also for things like quantum computing, which many researchers believe to be the future of computing. Instead of using classical bits (which can be either 1 and 0), quantum computing would use qubits, which can be 1, 0, or any quantum superposition of those two qubit states.

The result has been published in two papers in Physical Review Letters and Physical Review B.

Flow

Light-bending material could bridge quantum and classical physics

Scientists may have found a substance that allows them to finally link the opposing models of quantum and classical physics. In time, this finding could allow them to understand why the classical model breaks down at an quantum level, why quantum physics doesn’t seem to work at visible scales, and how the two can be reconciled.

Flow

Image credits SB Archer / Flickr

We know these two models of understanding the physical world — the quantum for really small bits and the classical for larger bits — don’t mix well together. Usually when one is in charge, the other is completely absent. Most of the rules of classical physics break down at the quantum level — gravity, for example, doesn’t seem to be doing much on the atomic level even as it’s literally holding the universe together overall. There’s nothing in the rules of classical physics that can explain quantum entanglement, either.

Scientists know that there must be something tying the two models together, but we’ve yet to find even a clue of what that is. Now, thanks to a newly developed material, scientists have a chance to see quantum mechanics in action on a scale visible to the naked eye — offering hope of finding a bridge between the two models.

“We found a particular material that is straddling these two regimes,” says team leader N. Peter Armitage, from Johns Hopkins University.

“Usually we think of quantum mechanics as a theory of small things, but in this system quantum mechanics is appearing on macroscopic length scales. The experiments are made possible by unique instrumentation developed in my laboratory.”

The material Armitage developed is a topological insulator, a class of material first theoretically predicted in the 1980s, and first produced in 2007. Topological insulators are conductive on their outer layer while being insulators on the internal one. This causes the electrons flowing along the material to do some pretty weird stuff. For example, Armitage and his team found that a beam of terahertz radiation (sometimes called THz or T-rays – an invisible spectrum of light) passing through their bismuth-selenium topological insulators can be made to rotate slightly — an effect only observed at the atomic scale up to now.

This rotation could be predicted with the same mathematical systems that govern quantum theory — making this the first time researchers have witnessed quantum mechanics occurring on the macro scale. It could form the basis on which the quantum and classical models can be linked, the ‘theory of everything’ that scientists have been trying to find for decades.

The experiment is definitely “a piece of the puzzle” but according to Armitage, there’s still a lot of work to be done before this link is fully understood. He hopes that one day we’ll have a completed picture of physics, and new materials like the team’s topological insulator might be the way we get there.

The full paper “Quantized Faraday and Kerr rotation and axion electrodynamics of a 3D topological insulator” has been published in the journal Science.

Quantum dot technology breakthrough brings it one step closer to a screen near you

Quantum dot technology breakthrough allows researchers to create near-perfect superstructures out of these tiny crystals.

Quantum dots are nano-sized semiconductor particles whose emission color can be tuned by changing their dimensions. They feature near-unity emission quantum yields and narrow emission bands, which result in excellent color purity. Their properties have singled them out as the next big thing in various fields of technology, particularly illuminating mediums.

The dots are incredibly tiny — each of these crystals is only made up of around 5,000 atoms. Because of their physical properties, including their ability to emit or absorb light of different wavelengths depending on how they’re manipulated, there has been a lot of interest in applying them in various fields of science and technology. But we’ve never been able to successfully tie the dots together without using another substance. These structures’ properties were degraded by the second fraction, severely hampering our use of quantum dots.

Now, a team from Cornell University’s School of Chemical and Biomolecular Engineering has found a way to overcome this obstacle, arranging quantum dots together in an almost perfect structure.

Quuantum dot solids hold the potential to become the next great development in the manufacture and design of semiconductors.
Image credits Kevin Whitham, Cornell University.

Image credits Kevin Whitham, Cornell University.

Previous efforts have found that when placed on a fluid surface the crystals could be fused together, as they would float similarly to oil on water. However this negatively impacted the quantum dots’ properties, hampering the effectiveness of the structure as a whole.

“Previously, they were just thrown together, and you hoped for the best,” says lead researcher Tobias Hanrath in a telephone interview with The Christian Science Monitor.

“It was like throwing a couple thousand batteries into a bathtub and hoping you get charge flowing from one end to the other.”

Dr. Hanrath and his team’s breakthrough will finally allow us to connect the dots without another substance that would impact their purity and structure. This finding represents the culmination of several years’ work for the team, which the professor described as “playing lego but with atomic-sized building blocks.”

“If you take several quantum dots, all perfectly the same size, and you throw them together, they’ll automatically align into a bigger crystal,” Hanrath says.

“It’s the same idea as a bucket of tennis balls automatically assuming an ordered pattern, or stacking cannonballs on top of each other.”

The team started from some of their previously published research, including a 2013 paper published in Nano Lettersin which they detailed a method of tying the dots through controlled displacement of connector molecules, called ligand. That paper referred to “connecting the dots” – i.e. electronically tying each quantum dot – as being one of the most persistent hurdles to be overcome.

Now, the team has found a way to make the crystals not only arrange themselves in an orderly fashion, but also stick to one another. This enables the creation of crystal superlattices that are defect-free.

But there is still a way to go before quantum dots can leave the lab for a screen near you. The structure of the superlattice, while superior to ligand-connected nanocrystal solids, is still limited in its electron wave function. In essence, the lattice isn’t perfectly uniform in structure because the crystals aren’t all identical in size.

“Take silicon,” says Hanrath. “Every silicon atom is the same size. In our case, the building blocks are almost the same size, but there is 5 percent variability in diameter, so you can’t make a perfect crystal superstructure, but as far as you can, we’ve pushed it to the point of perfection.”

The full paper, titled “Charge transport and localization in atomically coherent quantum dot solids” has been published online in the journal Nature Materials and is available here.

Quantum time-space asymmetry explains the origins of dynamics

Griffith University Associate Professor Joan Vaccaro believes she may have uncovered how our reality differentiates the future from the past. Her research paper, published in the journal Proceedings of the Royal Society A, could topple our understanding of time flow (ironically) forever.

Associate Professor Joan Vaccaro, of Griffith University’s Centre for Quantum Dynamics Credit: Griffith University.
Image via phys

A paper titled “Quantum asymmetry between time and space,” published by Associate Professor Joan Vaccaro of Griffith University’s Centre for Quantum Dynamics challenges our almost instinctual presumption that the flow of time is a fundamental part of nature. She suggests there may be a deeper origin to the incessant unfolding of the Universe around us over time due to a difference between the two directions of time: to the future and to the past.

“If you want to know where the universe came from and where it’s going, you need to know about time,” Vaccaro says.

“Experiments on subatomic particles over the past 50 years ago show that Nature doesn’t treat both directions of time equally. In particular, subatomic particles called K and B mesons behave slightly differently depending on the direction of time.”

Matter is thought of as restricted in space but not over time. In other words, matter simply exists at one point in space and not another. But if matter is restricted over time, it would mean that it pops in and out of existence, directly violating the law of mass conservation.

Traditionally, quantum mechanics overcomes this problem by assigning a fixed-over-time quantum state vector to matter. There is, however, no corresponding restriction of the state vector over space. This is done because matter is expected to evolve over time but with no corresponding presumption about its movement in space.

These axiomatically imposed restrictions create an asymmetry between time and space where systems are “forced” to evolve over time but not through space. This translates to equations of motion and conservation laws that operate differently over time and space.

However, Associate Professor Vaccaro used a “sum-over-paths formalism” to demonstrate the possibility of a time and space symmetry, meaning the conventional view of time evolution would need to be revisited.

“In the connection between time and space, space is easier to understand because it’s simply there. But time is forever forcing us towards the future,” says Associate Professor Vaccaro.

“Yet while we are indeed moving forward in time, there is also always some movement backwards, a kind of jiggling effect, and it is this movement I want to measure using these K and B mesons.”

The mathematics behind their concept is just…Mind breaking. But, the authors conclude that in their system a T (standing for time-reversal) violation is seen as being responsible for the fundamental differences between space and time in conventional quantum mechanics. Professor Vaccaro says the research provides a solution to the origin of dynamics, an issue that has long perplexed science.

The full paper can be found online here.

Perpetual motion machines still an impossibility – even in the quantum world

New research shows that negative absolute temperatures and perpetual motion machines are still out of reach, no matter how you tackle it, and no matter how small you try to make it.

A 1660 wood engraving of Robert Fludd’s 1618 “water screw” perpetual motion machine, widely credited as the first recorded attempt to describe such a device for useful work.
image: George A. Bockler

The concept of a perpetual motion machine has been an enticing one since it was first thought of. Unfortunately, it’s doomed to fail from the very start, by the very core of our physical laws. Imagine this: a machine that runs continuously without requiring any external energy, basically creating work without energy input – that sounds too good to be true; as a matter of fact, it is too good to be true, unless pretty much everything we know about physics turns out to be wrong. But that hasn’t stopped people from trying.

Some researchers (or faux researchers) have tried to defy the laws of thermodynamics, even going ahead and downright forging their results. More recently, people have moved from ‘traditional perpetual motion machines’ to microscopic ones. Inventions that relied on spin systems and ultracold quantum gas, seemed to suggest that perpetual motion machines may be more than pie-in-the-sky notions – to the untrained eye.

Now, researchers from MIT and the Max Planck Institute for Astrophysics have put the final nail in these alleged perpetual motion machines, showing that all these ideas, while innovative, don’t illustrate the dynamics of perpetual motion. The main claim of such experiments is that they are able to produce systems with negative absolute temperatures, or temperatures below 0 degrees Kelvin. If this were actually true, then than the machines could actually produce more work than the heat energy put into them – a key element of any perpetual motion machine.

“It’s sad in a sense, because you want something to be spectacular, and you want to find something new,” says Jörn Dunkel, an assistant professor of mathematics at MIT. “But it’s good, in a way, because the implications of negative absolute temperatures would have shaken up the foundations of physics.”

Dunkel and Stefan Hilbert, a postdoc at the Max Planck Institute, methodically analyzed the equations used in earlier studies to calculate absolute temperature. They found that, using the Gibbs equation, they calculated positive absolute temperatures in inverted systems that scientists had thought were negative. Their new calculations are fully compatible with the laws of thermodynamics as we know them and agree with standard measurement conventions for pressure and other thermodynamic variables. In other words, they showed that while a system may exhibit inverted spread of atomic or molecular energies, this doesn’t necessarily mean a negative absolute temperature.

“There are only a small number of textbooks that teach [Gibbs’] formula,” Dunkel says. “They don’t discuss negative temperatures, because at the time, it wasn’t really relevant. But then [the formula] got lost at some point, and now all the modern textbooks publish the other formula. To correct that will be difficult.”

Peter Hanggi, a professor of physics at the University of Augsburg, says the paper’s findings will help scientists make much more accurate interpretations of rare, exotic systems.

“There were a lot of things being claimed and repeated in the general literature over 50 years, and this group has done an excellent job in sorting out the incorrect from the correct,” says Hanggi, who was not involved in the research. “The main significance is to point out to everybody, ‘Hey, wait a minute, if you calculate temperature, what does it mean for thermodynamics and for the experiment?’ One cannot be too quick in their calculations.”

As for an eternal motion machine… the odds are anywhere between impossible and very slim.

“If you create a new class of systems, that’s a huge experimental feat,” Dunkel says. “But if you go on and interpret the things you measure on these systems, you need to be really careful. If you make just a small mistake in your assumptions, it can amplify hugely.”, Dunkel concludes.

Via MIT.

Finding black holes at a quantum scale

Most physicists believe that space is not smooth, but it is rather composed of incredibly small subunits, much like a painting made of dots. This micro-landscape is believed to host numerous black holes – black holes, that is, smaller than a trillionth of a trillionth of the diameter of a hydrogen atom, popping in and out of existence all the time.

The incredibly challenging hypothesis was created about 10 years ago, by researchers trying to fit in Einstein’s theory of gravity with quantum theory – something which would be a huge step towards a unified field theory of physics. Physicists have tried to use the LHC, in conjunction with gravitational wave detectors and observations of distant cosmic explosions to determine whether space is truly grainy, but so far, the results haven’t been clear.

Jacob Bekenstein proposes an experiment that could sort this out; his set up is designed to examine the problem at a scale of 10-35 meters. This is the Planck length – the size at which the macroscopic concept of distance loses its meaning and quantum fluctuations begin to cause space-time to resemble a foamy sea. Of course, we don’t have an instrument that can measure at this scale, so Bekenstein had to try something else. He proposes firing a single particle of light, a photon, through a transparent block, and then measure the minuscule distance that the block moves as a result of the photon’s impact.

So how would this work? Well, the wavelength of the photon, as well as the mass and size of the block are carefully chosen so that the given momentum will be large enough to move the block’s center of gravity by one Planck length; if space is in fact not grainy, each photon will pass through the detector and be measured at the other end. However, if the theory turns out to be correct, the photon is significantly less likely to make it all the way through the block.

“I argue that the consequence of that crossing — the translation of the block by a Planck length or so — is something nature would not like,” says Bekenstein.

Just imagine, at any given moment, a swarm of incredibly small black holes appears and disappears through the air. The photon is much larger than these black holes, so it is pretty much not bothered by them. But if the center of mass of the moving block falls into one of the holes, its movement will be impeded. Also, from the experiment set-up, the photon will not be able to pass through the block if it doesn’t move by a Planck length.

The experiment is quite doable with today’s possibilities, and it could prove to be monumental, if successful. However, interpreting the results and differentiating the quantum gravitational effects from other effects could be very hard; we’ll keep you posted as the experiment develops.

Physicists use humans to detect quantum effects

The quantum world is entirely different from what we see around us; it has its own laws, its own algebra, etc. It’s a really bizarre place, but that can yield wonderous developments as well. Since the quantum laws are so different, it’s hard to actually observe them, so instead, thought experiments are used. But for the first time, that has changed – researchers have used humans to actually observe the results of a quantum phenomena.

Quantum entanglement

Nicolas Gisin, a physicist at the University of Geneva in Switzerland created a test to see is human eyes can detect signs of entanglement. Quantum entanglement is a really weird and unexplainable fact, outside the quantum world: it practically links two or more objects in such a way that if you measure one’s properties, the other one’s properties are changed, no matter how far away they are from each other. Doesn’t make much sense does it ? But that’s how it goes in the quantum world. Quantum effects such as this one are typically limited to the microscopic world and are observed only through precise microscopes, thus indirectly.

He was inspired by an experiment carried out in Rome; professor Fabio Sciarrino and his team at La Sapienza University in Rome entangled a pair of photons and then ‘amplified’ one of them to create a shower of thousands of photons with the same quantum state.

“I immediately realized that the human eye could see that many photons,” says Gisin.

Making quantum visible for the naked eye

So he used a similar line-up, they entangled two photons; one of them was sent through a standard photon detector, while the other one was amplified using a machine that generated photons with the same polarization, and thus, at least in theory, generating a quantum micro-macro entanglement.

But here Gisin did something differently – he replaced the photon light field detector with a human. The beam of light produced by the amplifier could appear in one of two positions, and the location of the beam reflected the polarization state of the photons in the field. Gisin and his team sat in the dark for hours, marking the position of the light spot over repeated runs of the experiment, for the first time seeing the effects of quantum entanglement with the naked eye.

After a long and hard day’s work, they got the results they expected; the human results were double checked with photon detectors, and the results were positive, even though the latter were “faster and more reliable than humans and didn’t complain of tiredness”, according to Gisin.

A false positive

But the thing is, what they saw was not micro-macro entanglement. According to the laws of quantum physics, the act of measurement would break the entanglement, and thus the first photon and the light field could not be entangled (again, this goes against common sense).

“We set up the worst kind of amplifier precisely to see what result the standard Bell test would give, and it gave the wrong — positive — answer,” says Gisin.

The Bell test is the most common test to check the state of entanglement. According to Gisin, the reason for this false positive is that no detector is perfect, and some photons will always be lost during the experiment. Normally, this does not affect the Bell test, but Gisin says that as more photons come into play, the loophole hugely distorts the results. So regardless of the actual result, the Bell test would always be positive.

“This is brilliant work showing that if we do not control everything in the experiment, we can be fooled into thinking we have seen a macroscopic quantum effect, when we haven’t,” says Magdalena Stobińska, a quantum physicist at the Max Planck Institute for the Science of Light in Erlangen, Germany.

Sciarrino was not surprised by the results, and he says he already knew the Bell test couldn’t be fully trusted in such cases. Nevertheless, he applaudes the experiment.

“The experiment is lovely because in this sense you can ‘see’ entanglement,” says Sciarrino. “It brings quantumness closer to human experience.”

Quantum leap: bits of light successfully teleported

The world we live in is getting closer and closer to Star Trek everyday. Scientists announced today they were able to teleport special bits of light from one place to another. While this doesn’t mean that we will be (ever) able to teleport people, it involves some pretty awesome mind bending physics.

Teleportation relies on a special quantum property called entanglement, about which I told you about in an article about quantum computers. Basically, two particles can be bonded so that even though there is a large distance between them, they are able to communicate directly, and what happens to one affects the other. This property was so bizarre that it fascinated even Einstein, who named it “spooky action at distance”.

To teleport light, researchers led by Noriyuki Lee of the University of Tokyo had to destroy it in one place, and re-create it in another. This actually isn’t the first time light has been teleported in this way, but this time it’s much more complicated because the teleported light wasn’t just light, it was a special quantum state called a Schrödinger’s-cat state. Schrödinger’s cat refers to a thought experiment, that suggests that some properties of particles are not decided until an observer decides to measure them. Kind of hits your brain, but that’s pretty much how quantum mechanics works.

Even though this represents a major breakthrough in teleporting, it is extremely unlikely we will be dealing with teleporting of any life forms in the next decades.

“There is not at present a way to teleport even a bacteria,” said Philippe Grangier, of France’s Institut d’Optique, who was not involved in the new research, but who wrote an accompanying essay on the finding in the same issue of Science . “For a real cat I don’t think this will be possible in any possible future.”

Atom nuclei can store information

In case you’re wondering, what you’re looking at is a silicon chip, only 1 millimeter square that was used by researchers to prove how data can be stored in the magnetic spin of atoms – and how it can then be accessed electronically. Physicists from the University of Utah have managed to store information in the magnetic spin of a phosphorus atom, which is a major step in developing new types of memory for both traditional and quantum computers.

“The length of spin memory we observed is more than adequate to create memories for computers,” says Christoph Boehme (pronounced Boo-meh), an associate professor of physics and senior author of the new study, published Friday, Dec. 17 in the journal Science. “It’s a completely new way of storing and reading information.”

The technical difficulties they had to face were huge; the apparatus they used only works at 3.2 Kelvin grades, which is just slightly above absolute zero – the temperature at which all atoms reach a standstill ! Also, it had to be surrounded by an electric field roughly 200.000 greater than that of the Earth.

“Yes, you could immediately build a memory chip this way, but do you want a computer that has to be operated at 454 degrees below zero Fahrenheit and in a big national magnetic laboratory environment?” Boehme says. “First we want to learn how to do it at higher temperatures, which are more practical for a device, and without these strong magnetic fields to align the spins.”
As for obtaining an electrical readout of data held within atomic nuclei, “nobody has done this before,” he adds.

LHC produces first results

Since the Large Hadron Collider went back in business, all sort of rumors have been circling the scientific circles (and not only). However, until these rumors are proven wrong or right, the first official paper on proton collisions from the Large Hadron Collider has been published in this week’s edition of Springer’s European Physical Journal C. .

lhc

Designed to reach the highest energy ever explored in particle accelerators, it features a circular tunnel with the circumference of 27 km. Since it’s been recommissioned, a total of 284 collisions have been recorded, all of which have been analyzed and interpreted. The researchers have been able to determine what is called ‘pseudorapidity density’ (the average number of charged particles that are emitted perpendicular to the beam direction. The goal of this was to compare the results with those obtained in the case of proton-antiproton collisions that took place in the same conditions.

The paper was published by ALICE (a Large Ion Collider Experiment that brings together authors from 113 institutions). As well as the actual results, the paper also explains how their detecting and analyzing system works. The results are not only consistent with earlier measurements, but they also fit the theoretical model produced by researchers.

Dr. Jürgen Schukraft from CERN and ALICE spokesperson said: “This important benchmark test illustrates the excellent functioning and rapid progress of the LHC accelerator, and of both the hardware and software of the ALICE experiment, in this early start-up phase. LHC and its experiments have finally entered the phase of physics exploitation.”

Dark matter discovered, or at least rumor has it

Well, rumors and science never go well together, especially when it goes to something as important as the work going on at LHC, who just got back in business a short while ago.

Dark matter map

Dark matter map

My first reaction was to believe it was just a rumor. However, after hearing and reading many articles on this I still find it hard to believe. However, what really made me think was that everybody was going on and saying how this find would bring a major change in our understanding of the Universe. I think it wouldn’t; let me explain.

First of all, I don’t know if they discovered dark matter or not yet. I’m waiting for the official announcement as much as the next guy. It would be indeed a major breakthrough, but it wouldn’t change our understanding, it would just confirm it. Researchers have long theorized that dark matter exists and that it is responsible for about 90% of the Universe’s mass. They can’t see it, but deducted it exists because of the gravitational forces. So basically, a lot of our understanding of the Universe relies on the fact that dark matter exists.

The big change would be if they recreated the right conditions and didn’t find it! It would be so significant, that basically we’d have to rethink modern physics. Same goes for the Higgs boson. I mean, with current knowledge, scientists have been able to demonstrate that these particles exist; if they are indeed found, we’re right, we can move on to finding more things, hurray. But if they’re not… things really get messy.

So, what do you think the LHC will bring? Will it break once again, shed light on everything it can, destroy the world, what? Tell everybody on the Facebook page

First Universal Two-Qubit quantum processor created

qbitPhysicists from NIST (National Institute of Standards and Technology) have demonstrated what they claim to be the first universal programmable quantum information processor that will be able to run any program allowed by quantum mechanics (the set of principles that describe the atomic and subatomic matter). They managed to accomplish this using two quantum bits (qubits) of information.

This processor could prove to be a major breakthrough for a future quantum computer, that could very well be the ‘evolutionary leap’ in the computers’ life thus resulting the possible solve of problems that are untouchable today. The discovery was presented in the latest edition of Nature Physics and this marks the first time anybody has moved beyond asking a single task from a quantum computer.

“This is the first time anyone has demonstrated a programmable quantum processor for more than one qubit,” says NIST postdoctoral researcher David Hanneke, first author of the paper. “It’s a step toward the big goal of doing calculations with lots and lots of qubits. The idea is you’d have lots of these processors, and you’d link them together.”

The processor basically stores binary information in just two beryllium ions held in an electromagnetic ‘trap’, and then handled with ultraviolet lasers. With these in hand, the NIST team managed to perform 160 different processing routines using just the two qubits. Although practically there is an infinite number of programs you can perform with the two qubits, the 160 are pretty much totally relevant, and they prove that the processor is “universal”, Hanneke says.

Of course there will be many more qubits and logic operations to solve bigger problems, but when you come to think about it, all this was done with just two atoms, basically; and the operations they performed were no easy task. Each program consisted of 31 logic operations, 15 of which were varied during programming.

Meet the world’s most powerful X-Ray laser

homerThe first experiments with this laser (Linac Coherent Light Source) have been given the green light at the Department of Energy’s SLAC National Accelerator Laboratory. The illuminating of objects and processing speed will take place at an unprecedented scale, promising groundbreaking research in physics, chemistry, biology and numerous other fields.

“No one has ever had access to this kind of light before,” said LCLS Director Jo Stöhr. “The realization of the LCLS isn’t only a huge achievement for SLAC, but an achievement for the global science community. It will allow us to study the atomic world in ways never before possible.”

Early experiments are already showing some promise, providing insight on fundaments of atoms and molecules, underlying their properties. The short term goal is to create stop action frames for molecules in motion. By putting together many of these images to create a film, scientists will create for the first time a film with actual molecules in motion, being able to see chemical molecules bond and break, as well as actually see how atoms interact at a quantum level.

“It’s hard to overstate how successful these first experiments have been,” said AMO Instrument Scientist John Bozek. “We look forward to even better things to come.”