Tag: speed of light

The Future of Computing: Towards a Quantum Internet

quantun_internetFor decades, the dream of quantum computing – a system that makes direct use of quantum-mechanical phenomena, such as superposition and entanglement, to perform operations on data- has been just that. Much the same is true of principles that expand on this concept, such as quantum encryption and a quantum internet. But thanks to ongoing studies and experiments by researchers and scientists, that dream may be closer to fruition than ever.

This time the progress comes from a research team out of Professor Nicolas Gisin lab’s in the physics department at the University of Geneva. The team achieved the teleportation of the quantum state of a photon – this time, the photon’s polarization – to a crystal-encased photon more than 25 kilometers (15.5 miles) away. The distance breaks the previous record of 6 kilometers (3.7 miles) set 10 years ago by the same team using the same method.

quantum_crystalThis is the latest in a series of experiments the group, led by physicist Félix Bussières, have conducted over the last decade in an effort to better understand quantum data transfer. In this particular experiment, the researchers stored one photon in a crystal, essentially creating a solid-state memory bank. They sent another photon of a different wavelength 25 km away through optical fiber, whereupon they had it interact with a third photon.

Because the first two photons were entangled – a quantum property whereby particles can speak to each other across an infinite distance – the interaction sent the data to the photo stored in the memory bank, where the team was able to retrieve it. Or as the team explained, using pool balls as an anology:

It is a bit like a game of billiards, with a third photon hitting the first which obliterates both of them. Scientists measure this collision. But the information contained in the third photon is not destroyed – on the contrary it finds its way to the crystal which also contains the second entangled photon.

quantum-entanglement3This is all in keeping with the concept of quantum teleportation – the moving of quantum data from one location to another without having to travel the distance between them. That means that the speed at which data moves isn’t necessarily limited by the constraints of space and time. In that sense, it’s easier to think of this kind of teleporting not as a “beam me up” scenario, but as a kind of instantaneous awareness between two points.

While this may not sound as exciting as Ursula K. Le Guin’s Ansible communicator, the Alcubierre warp drive, or the “Star Trek”-style transporter, it opens up startling possibilities. For instance, in addition to bringing us closer to hard drives that can store quantum bits (aka. qubits), this is a major step in the direction of a quantum internet and encryption- where information is sent around the world instantaneously and is extremely secure.

quantum-teleportation-star-trails-canary-islands-1-640x353This also opens doors for space exploration, where astronauts in space, rovers on Mars, and satellites in deep space will be able to communicate instantly with facilities here on Earth. For non-quantum physicists, the novel aspect of this experiment is that the team achieved teleportation of data across the kind of optic fiber that forms the basis of modern-day telecommunications, which means no major overhaul will be needed to make quantum internet a reality.

As physicists continue to push the boundaries of our understanding about the quantum world, we’re getting closer to translating these kinds of advancements in market applications. Already, quantum computing and quantum encryption are making inroads into the sectors of banking security, medical research and other areas in need of huge computing muscle and super-fast information transfer.

^With the rise of a potential quantum Internet on the horizon, we could see the next jump in communication happen over the next couple of decades. So while we’re a long way off from trying to pry quantum teleportation and entanglement from the grip of the theoretical realm, scientists are making headway, if only a handful of kilometers at a time. But every bit helps, seeing as how routing stations and satellites can connect these distances into a worldwide network.

In fact, research conducted by other labs have not only confirmed that quantum teleportation can reach up to 143 km (89 miles) in distance, but that greater and greater properties can be beamed. This distance is especially crucial since it happens to be close to what lies between the Earth and a satellite in Low-Earth Orbit (LEO). In short, we humans could construct a quantum internet using optic cables or satellites, mirroring the state of telecommunications today.

And when that happens, get ready for an explosion in learning, processing and information, the likes of which has not been seen since the creation of the printing press or the first internet revolution!

Sources: cnet.com, technologyreview.com, nature.com

NASA’s Proposed Warp-Drive Visualized

ixs-enterpriseIt’s no secret that NASA has been taking a serious look at Faster-Than-Light (FTL) technology in recent years. It began back in 2012 when Dr Harold White, a team leader from NASA’s Engineering Directorate, announced that he and his team had begun work on the development of a warp drive. His proposed design, an ingenious re-imagining of an Alcubierre Drive, may eventually result in an engine that can transport a spacecraft to the nearest star in a matter of weeks — and all without violating Einstein’s law of relativity.

In the spirit of this proposed endeavor, White chose to collaborate with an artist to visualize what such a ship might look like. Said artist, Mark Rademaker, recently unveiled the fruit of this collaboration in the form of a series of concept images. At the heart of them is a sleek ship nestled at the center of two enormous rings that create the warp bubble. Known as the IXS Enterprise, the ship has one foot in the world of science fiction, but the other in the realm of hard science.

ixs-enterprise-0The idea for the warp-drive comes from the work published by Miguel Alcubierre in 1994. His version of a warp drive is based on the observation that, though light can only travel at a maximum speed of 300,000 km/sec (186,000 miles per second, aka. c), spacetime itself has a theoretically unlimited speed. Indeed, many physicists believe that during the first seconds of the Big Bang, the universe expanded at some 30 billion times the speed of light.

The Alcubierre warp drive works by recreating this ancient expansion in the form of a localized bubble around a spaceship. Alcubierre reasoned that if he could form a torus of negative energy density around a spacecraft and push it in the right direction, this would compress space in front of it and expand space behind it. As a result, the ship could travel at many times the speed of light while the ship itself sits in zero gravity – hence sparing the crew from the effects of acceleration.

alcubierre-warp-drive-overviewUnfortunately, the original maths indicated that a torus the size of Jupiter would be needed, and you’d have to turn Jupiter itself into pure energy to power it. Worse, negative energy density violates a lot of physical limits itself, and to create it requires forms of matter so exotic that their existence is largely hypothetical. In short, what was an idea proposed to circumvent the laws of physics itself fell prey to their limitations.

However, Dr Harold “Sonny” White of NASA’s Johnson Space Center reevaluated Alcubierre’s equations and made adjustments that corrected for the required size of the torus and the amount of energy required. In the case of the former, White discovered that making the torus thicker, while reducing the space available for the ship, allowed the size of it to be greatly decreased – from the size of Jupiter down to a width of 10 m (30 ft), roughly the size of the Voyager 1 probe.

alcubierre-warp-drive-overviewIn the case of the latter, oscillating the bubble around the craft would reduce the stiffness of spacetime, making it easier to distort. This would reduce the amount of energy required by several orders of magnitude, for a ship traveling ten times the speed of light. According to White, with such a setup, a ship could reach Alpha Centauri in a little over five months. A crew traveling on a ship that could accelerate to just shy of the speed of light be able to make the same trip in about four and a half years.

Rademaker’s renderings reflect White’s new calculations. The toruses are thicker and, unlike the famous warp nacelles on Star Trek’s Enterprise, their design is the true function of hurling the craft between the stars. Also, the craft, which is divided into command and service modules, fits properly inside the warp bubble. There are some artistic additions, such as some streamlining, but no one said an interstellar spaceship couldn’t be functional and pretty right?

ixs-enterprise-2For the time being, White’s ideas can only be tested on special interferometers of the most exacting precision. Worse, the dependence of the warp on negative energy density is a major barrier to realization. While it can, under special circumstances, exist at a quantum level, in the classical physical world that this ship must travel through, it cannot exist except as a property of some form of matter so exotic that it can barely be said to be capable of existing in our universe.

Though no one can say with any certainty when such a system might be technically feasible, it doesn’t hurt to look ahead and dream of what may one day be possible. And in the meantime, you can check out Rademaker’s entire gallery by going to his Flickr account here. And be sure to check out the video of Dr. White explaining his warp-drive concept at SpaceVision 2013:


Sources: gizmag.com,  IO9.com, cnet.com, flickr.com

More News in Quantum Computing!

quantum-computers-The-Next-GenerationRecently, a team of researchers at the University of Rochester conducted an experiment where they managed to suspend a nano-sized diamond in free space with a laser. The purpose of the experiment was to measure the amount of light emitted from the diamond, but had the added bonus of demonstrating applications that could be useful in the field of quantum computing.

For those unfamiliar with the concept, quantum computing differs from conventional computing since it does not rely on sending information via a series of particles (electrons) through one-way channels. Instead, quantum computing relies on the process of beaming the states of particles (i.e. a photons quantum properties) from one location to the next.

nanodiamondSince this process occurs faster than the speed of light (as no movement takes place) and qubits (quantum bits) have the ability to be in more than one state simultaneously, computations done using this model would be exponentially faster. But despite many advancements made in recent years, the field remains largely theoretical and elusive.

To conduct their experiment, the researchers focused a laser into a 25 cm (10 inch) chamber and then sprayed an aerosol containing dissolved nanodiamonds inside. These nanodiamonds were attracted to the laser in a technique known as “laser trapping”, until a single particle was isolated and made to levitate. Once the tiny gem was levitating in free space, the researchers used another laser to make defects within the diamond emit light at given frequencies.

nanodiamond1This process is known as photoluminescence – a form light emission that is caused by defects in the tiny diamond that allows for the absorptions of photons. When the system is excited, it changes the spin; and when the it relaxes after the change, other photons are emitted. This occurs because nitrogen atoms replace some of the carbon atoms in the diamond. Once the nitrogen is nested in the diamond’s atomic structure, it is possible to excite electrons with a laser.

According to the researchers, this photoluminescence process has the potential to excite the system and cause what is known as Bohr spin quantum jumps, which are changes in spin configuration of the internal defect. This occurs because nitrogen atoms replace some of the carbon atoms in the diamond. Once the nitrogen is nested in the diamond’s atomic structure, it is possible to excite electrons with a laser.

????????????????????In addition, the potential also exists to turn the nanodiamond into an optomechanical resonator. According to Nick Vamivakas, an assistant professor of optics at the University of Rochester, these are structures in which the vibrations of the system can be controlled by light. Optomechanical resonators have the potential to be used as incredibly precise sensors, which could lead to uses in microchips.

In addition, these resonator systems have the potential to create Schrödinger Cat states, which are typically not found in microscopic objects. As anyone who’ familiar with Futurama or Big Bang Theory may recall, this refers to the thought experiment where a cat is inside a box with poison, and until someone opens the box and determines its whereabouts, the cat could be considered simultaneously both alive and dead.

^Being able to stimulate matter so that it can exist in more than one state at any given time is not only revolutionary, it is a clear step towards the creation of machines that exploit this principle to perform computations. According to Nick Vamivakas, an assistant professor of optics at the University of Rochester, explained:

Cat or cat-like states contradict our everyday experiences since we do not see common things in quantum states. The question is: where is this boundary between microscopic and macroscopic? By generating quantum states of larger and larger objects, we can hone in on a boundary … if there is one.

Naturally, the Rochester team is still a long way from achieving their big breakthrough, and Vamivakas himself admits that he does not know how far away a quantum computing truly is. In terms of this latest experiment, the team still needs to cool the crystal better, which they are hoping can be achieved with a few technical improvements. And then they hope to find a better way of running the experiment than spraying nanodiamond dust into a tube.

In the meantime, check out this video of the experiment. It promises to be “illuminating” (sorry!):


Source: gizmag.com