Microsofts HoloLens 2 may go on sale in September

first_imgMicrosoft’s second generation HoloLens is coming in September. James Martin/CNET Microsoft revealed its HoloLens 2 at Mobile World Congress earlier this year, and now we know when we’ll be able to get our hands on it. During a speech at the World Artificial Intelligence Conference in Shanghai, executive vice president Harry Shum revealed that its next-generation augmented reality headsets goes on sale in September, Reuters reported.The updated HoloLens is available to preorder for $3,500 (about £2,700 or AU$4,900), and comes four years after the original version. The new one is more comfortable, and has a greater field of view and better eye and hand tracking, according to CNET’s Ian Sherr and Scott Stein. In an emailed statement, Microsoft confirmed that HoloLens 2 will begin shipping later this year, but didn’t confirm that it’ll arrive in September.”We have started collecting expressions of interest for HoloLens 2 preorders and, as part of our standard practice for gathering feedback, have shared near-final prototypes with some customers, but have not announced a date for general availability,” a spokesperson wrote.First published at Aug. 29 at 2:06 a.m. PT.Updated at Aug. 30 at 3:50 a.m. PT: Adds Microsoft statement. 4:54 Comments 4 Share your voice Tags Augmented reality (AR) Microsoft Wearable Tech Microsoft HoloLens 2: A first dive into the future of… Now playing: Watch this:last_img read more

Atari Movie Makers Plan to Raise 40 Million via Bushnell Token Sale

first_img Popular on Variety ×Actors Reveal Their Favorite Disney PrincessesSeveral actors, like Daisy Ridley, Awkwafina, Jeff Goldblum and Gina Rodriguez, reveal their favorite Disney princesses. Rapunzel, Mulan, Ariel,Tiana, Sleeping Beauty and Jasmine all got some love from the Disney stars.More VideosVolume 0%Press shift question mark to access a list of keyboard shortcutsKeyboard Shortcutsplay/pauseincrease volumedecrease volumeseek forwardsseek backwardstoggle captionstoggle fullscreenmute/unmuteseek to %SPACE↑↓→←cfm0-9Next UpJennifer Lopez Shares How She Became a Mogul04:350.5x1x1.25×1.5x2xLive00:0002:1502:15 The makers of the upcoming Atari movie about the iconic video game console maker are eschewing traditional film financing models for a blockchain-powered initial coin offering (ICO), and plan to sell coins named after Atari founder Nolan Bushnell via a private pre-sale this spring. Film production and financing company Vision Tree plans to raise as much as $40 million with the sale of these Bushnell tokens.“While the film has received offers from conventional and studio-sourced financing, we have elected cryptocurrency funding to accelerate the filmmaking path in a whole new way, offering Atari fans the opportunity to share in the creation of this movie with us,” producer J.D. Seraphine told Variety.Owners of Bushnell tokens will get a share of the earnings of the movie, and they will also be able to vote on the trailer, and even help select cast members. “We wanted to enable Atari fans and gamers to co-own the project and the experience,” said Seraphine. “This open approach is also more in the DNA and the same spirit of Atari.”center_img This isn’t the first time that filmmakers are jumping onto the blockchain bandwagon. Earlier this week, Variety was first to report that the indie movie “No Postage Necessary” will use a blockchain-based app for promotion and distribution when it is being released this June.Seraphine told Variety that he has high hopes for the technology. “Blockchain technology and cryptocurrency financing will enable independent filmmakers and artists to not only create, but also own their projects that they can then grow over the span of their own career,” he said.The Atari movie is currently in pre-production, and is being produced by Leonardo DiCaprio’s production company Appian Way as well as Vision Tree and Avery Productions. It’s being pitched as a biopic about Atari’s founder and his life story of starting out as a pinball machine repairman who went on to found one of the most iconic video game console brands.Bushnell’s time at Atari recently came under scrutiny after allegations surfaced that he fostered a sexist culture at Atari. Bushnell was set to receive an award at the Game Developers Conference in San Francisco this week, but the conference rescinded the award in response to these allegations.At the time, Bushnell applauded the conference’s decision and apologized for any past indiscretions. In a statement sent to Variety this week, Bushnell chose to instead paint a different picture of Atari:“We created some extremely strong and capable professional women at Atari. Equal pay for equal work. Promoting women due to capability, and gender not being a promotional construct. We elevated women’s rights to the pinnacle of that time, and I’d do it all again just the same way.”last_img read more

The path to perfection Quantum dots in electricallycontrolled cavities yield bright nearly

first_img © 2016 Phys.org , Nature Communications Researchers develop ideal single-photon source Figure 1. a, Schematic of the sources: a single semiconductor quantum dot, represented by a red dot, is positioned within 50 nm from the center of the cavity, which consists of a 3 µm pillar connected to a circular frame through 1.3 µm wide waveguides. The top electrical contact is defined on a large mesa adjacent to the circular frame. By applying a bias to the cavity, the wavelength of the emitted photons can be tuned and the charge noise strongly reduced. b, Emission map of the device: the strong signal coming from the quantum dot located at the center of the cavity demonstrates the precise positioning of the quantum dot in the cavity and the enhanced collection efficiency obtained by accelerating the quantum dot spontaneous emission. Credit: Courtesy: Dr. Pascale Senellart. Figure 2. a, Photon correlation histogram measuring the indistinguishability of photons successively emitted by one of the devices. The area of the peak at zero delay allows measuring the photon indistinguishability: it should be zero for fully indistinguishable photons. We test here two configurations: the coalescence of photons with orthogonal polarization (fully distinguishable – blue curve) and the coalescence of photon with the same polarization (red curve). The disappearance of the zero delay peak in the latter case show the near unity indistinguishability of the emitted photons. b, Graph summarizing all the source characteristics as a function of excitation power: brightness (probability of collecting a photon per pulse – red – right scale), autocorrelation function g(2)(0) (characterizing the probability of emitting more than one photon – blue – left bottom scale), indistinguishablity M (purple – left top scale). Credit: Courtesy: Dr. Pascale Senellart. Explore further , Optica , Nature Nanotechnology , Nature Dr. Pascale Senellart and Phys.org discussed the paper, Near-optimal single-photon sources in the solid state, that she and her colleagues published in Nature Photonics, which reports the design and fabrication of the first optoelectronic devices made of quantum dots in electrically controlled cavities that provide bright source generating near-unity indistinguishability and pure single photons. “The ideal single photon source is a device that produces light pulses, each of them containing exactly one, and no more than one, photon. Moreover, all the photons should be identical in spatial shape, wavelength, polarization, and a spectrum that is the Fourier transform of its temporal profile,” Senellart tells Phys.org. “As a result, to obtain near optimal single photon sources in an optoelectronic device, we had to solve many scientific and technological challenges, leading to an achievement that is the result of more than seven years of research.”While quantum dots can be considered artificial atoms that therefore emit photons one by one, she explains, due to the high refractive index of any semiconductor device, most single photons emitted by the quantum dot do not exit the semiconductor and therefore cannot be used. “We solved this problem by coupling the quantum dot to a microcavity in order to engineer the electromagnetic field around the emitter and force it to emit in a well-defined mode of the optical field,” Senellart points out. “To do so, we need to position the quantum dot with nanometer-scale accuracy in the microcavity.”Senellart notes that this is the first challenge that the researchers had to address since targeting the issue of quantum dots growing with random spatial positions. “Our team solved this issue in 20081 by proposing a new technology, in-situ lithography, which allows measuring the quantum dot position optically and drawing a pillar cavity around it. With this technique, we can position a single quantum dot with 50 nm accuracy at the center of a micron-sized pillar.” In these cavities, two distributed Bragg reflectors confine the optical field in the vertical direction, and the contrast of the index of refraction between the air and the semiconductor provides the lateral confinement of the light. “Prior to this technology, the fabrication yield of quantum dot cavity devices was in the 10-4 – but today it is larger than 50%.” The scientists used this technique to demonstrate the fabrication of bright single photon sources in 20132, showing that the device can generate light pulses containing a single photon with a probability of 80% – but while all photons had the same spatial shape and wavelength, they were not perfectly identical. More information: Near-optimal single-photon sources in the solid state, Nature Photonics 10, 340–345 (2016), doi:10.1038/nphoton.2016.23Related:1Controlled light–matter coupling for a single quantum dot embedded in a pillar microcavity using far-field optical lithography, Physical Review Letters 101, 267404 (2008), doi:10.1103/PhysRevLett.101.2674042Bright solid-state sources of indistinguishable single photons, Nature Communications 4, 1425 (2013), doi:10.1038/ncomms24343Deterministic and electrically tunable bright single-photon source, Nature Communications 5, 3240 (2014), doi:10.1038/ncomms42404On-demand semiconductor single-photon source with near-unity indistinguishability, Nature Nanotechnology 8, 213–217 (2013), doi:10.1038/nnano.2012.2625Coherent control of a solid-state quantum bit with few-photon pulses, arXiv:1512.04725 [quant-ph]6Charge noise and spin noise in a semiconductor quantum device, Nature Physics 9, 570–575 (2013), doi:10.1038/nphys26887Scalable performance in solid-state single-photon sources, Optica 3, 433-440 (2016), doi:10.1364/OPTICA.3.0004338BosonSampling with single-photon Fock states from a bright solid-state source, arXiv:1603.00054 [quant-ph]9Downconversion quantum interface for a single quantum dot spin and 1550-nm single-photon channel,Optics Express Vol. 20, Issue 25, pp. 27510-27519 (2012), doi:10.1364/OE.20.02751010Ultrabright source of entangled photon pairs, Nature 466, 217–220 (08 July 2010), doi:10.1038/nature09148 Citation: The path to perfection: Quantum dots in electrically-controlled cavities yield bright, nearly identical photons (2016, June 7) retrieved 18 August 2019 from https://phys.org/news/2016-06-path-quantum-dots-electrically-controlled-cavities.html Journal information: Nature Photonics Optical quantum technologies are based on the interactions of atoms and photons at the single-particle level, and so require sources of single photons that are highly indistinguishable – that is, as identical as possible. Current single-photon sources using semiconductor quantum dots inserted into photonic structures produce photons that are ultrabright but have limited indistinguishability due to charge noise, which results in a fluctuating electric field. Conversely, parametric down conversion sources yield photons that while being highly indistinguishable have very low brightness. Recently, however, scientists at CNRS – Université Paris-Saclay, Marcoussis, France; Université Paris Diderot, Paris, France; University of Queensland, Brisbane, Australia; and Université Grenoble Alpes, CNRS, Institut Néel, Grenoble, France; have developed devices made of quantum dots in electrically-controlled cavities that provide large numbers of highly indistinguishable photons with strongly reduced charge noise that are 20 times brighter than any source of equal quality. The researchers state that by demonstrating efficient generation of a pure single photon with near-unity indistinguishability, their novel approach promises significant advances in optical quantum technology complexity and scalability. , Physical Review Letters Senellart adds that while removing scattered photons when transmitting light in processed microstructures is typically complicated, in their case this step was straightforward. “Because the quantum dot is inserted in a cavity, the probability of the incident laser light to interact with the quantum dot is actually very high. It turns out that we send only a few photons – that is, less than 10 – on the device to have the quantum dot emitting one photon. This beautiful efficiency, also demonstrated in the excitation process, which we report in another paper5, made this step quite easy.”The devices reported in the paper have a number of implications for future technologies, one being the ability to achieve strongly-reduced charge noise by applying an electrical bias. “Charge noise has been extensively investigated in quantum dot structures,” Senellart says, “especially by Richard Warburton’s group.” Warburton and his team demonstrated that in the best quantum dot samples, the charge noise could take place on a time scale of few microseconds6 – which is actually very good, since the quantum dot emission lifetime is around 1 nanosecond. However, this was no longer the case in etched structures, where a strong charge noise is always measured on very short time scale – less than 1 ns – that prevents the photon from being indistinguishable. “I think the idea we had – that this problem would be solved by applying an electric field – was an important one,” Senellart notes. “The time scale of this charge noise does not only determine the degree of indistinguishability of the photons, it also determines how many indistinguishable photon one can generate with the same device. Therefore, this number will determine the complexity of any quantum computation or simulation scheme one can implement.” Senellart adds that in a follow-up study7 the scientists generated long streams of photons that can contain more than 200 being indistinguishable by more than 88%.In addressing how these de novo devices may lead to new levels of complexity and scalability in optical quantum technologies, Senellart first discusses the historical sources used develop optical quantum technologies. She makes the point that all previous implementations of optical quantum simulation or computing have been implemented using Spontaneous Parametric Down Conversion (SPDC) sources, in which pairs of photons are generated by the nonlinear interaction of a laser on a nonlinear crystal, wherein one photon of the pair is detected to announce the presence of the other photon. This so-called heralded source can present strongly indistinguishable photons, but only at the cost of extremely low brightness. “Indeed, the difficulty here is that the one pulse does not contain a single pair only, but some of the time several pairs,” Senellart explains. “To reduce the probability of having several pairs generated that would degrade the fidelity of a quantum simulation, calculation or the security of a quantum communication, the sources are strongly attenuated, to the point where the probability of having one pair in a pulse is below 1%. Nevertheless, with these sources, the quantum optics community has demonstrated many beautiful proofs of concept of optical quantum technologies, including long-distance teleportation, quantum computing of simple chemical or physical systems, and quantum simulations like BosonSampling.” (A BosonSampling device is a quantum machine expected to perform tasks intractable for a classical computer, yet requiring minimal non-classical resources compared to full-scale quantum computers.) “Yet, the low efficiency of these sources limits the manipulation to low photon numbers: It takes typically hundreds of hours to manipulate three photons, and the measurement time increases exponentially with the number of photons. Obviously, with the possibility to generate more many indistinguishable photons with an efficiency more than one order of magnitude greater than SPDC sources, our devices have the potential to bring optical quantum technologies to a whole new level.”Other potential applications of the newly-demonstrated devices will focus on meeting near-future challenges in optical quantum technologies, including scalability of photonic quantum computers and intermediate quantum computing tasks. “The sources presented here can be used immediately to implement quantum computing and intermediate quantum computing tasks. Actually, very recently – in the first demonstration of the superiority of our new single photon sources – our colleagues in Brisbane made use of such bright indistinguishable quantum dot-based single photon sources to demonstrate a three photon BosonSampling experiment8, where the solid-state multi-photon source was one to two orders-of-magnitude more efficient than downconversion sources, allowing to complete the experiment faster than those performed with SPDC sources. Moreover, this is a first step; we’ll progressively increase the number of manipulated photons, in both quantum simulation and quantum computing tasks.”Another target area is quantum communications transfer rate. “Such bright single photon sources could also drastically change the rate of quantum communication protocols that are currently using attenuated laser sources or SPDC sources. Yet, right now, our sources operate at 930 nm when 1.3 µm or 1.55 µm sources are needed for long distance communications. Our technique can be transferred to the 1.3 µm range, a range at which single photon emission has been successfully demonstrated – in particular by the Toshiba research group – slightly changing the quantum dot material. Reaching the 1.55 µm range will be more challenging using quantum dots, as it appears that the single photon emission is difficult to obtain at this wavelength. Nevertheless, there’s a very promising alternative possibility: the use of a 900 nm bright source, like the one we report here, to perform quantum frequency conversion of the single photons. Such efficient frequency conversion of single photons has recently been demonstrated, for example, in the lab of Prof. Yoshie Yamamoto at Stanford9.”Regarding future research, Senellart says “There are many things to do from this point. On the technology side, we will try to improve our devices by further increasing the source brightness. For that, a new excitation scheme will be implemented to excite the device from the side, as was done by Prof. Valia Voliotis and her colleagues on the Nanostructures and Quantum Systems team at Pierre and Marie Curie University in Paris and Prof. Glenn Solomon’s group at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland. Applying this technique to our cavities should allow gaining another factor of four on source brightness. In addition, operating at another wavelength would be another important feature for our devices, since as discussed above, this would allow using the source for quantum telecommunication. For example, a shorter wavelength, in the visible/near infrared range, would open new possibilities to interconnect various quantum systems, including ions or atoms through their interaction with photons, as well as applications in quantum imaging and related fields.” The researchers also want to profit from the full potential of these sources and head to high photon number manipulation in, for instance, quantum simulation schemes. “We’re aiming at performing BosonSampling measurements with 20-30 photons, with the objective of testing the extended Church Turing thesis and proving the superiority of a quantum computer over a classical one.” The original Church Turing thesis, based on investigations of Alonzo Church and Alan Turing into computable functions, states that, ignoring resource limitations, a function on the natural numbers is computable by a human being following an algorithm, if and only if it is computable by a Turing machine.Another promising impact on future optical quantum technologies is the generation of entangled photon pairs. “A quantum dot can also generate entangled photon pairs, and in 2010 we demonstrated that we could use the in situ lithography to obtain the brightest source of entangled photon pairs10. That being said, photon indistinguishability needs to be combined with high pair brightness – and this is the next challenge we plan to tackle. Such a device would play an important role in developing quantum relays for long distance communication and quantum computing tasks.”Senellart tells Phys.org that other areas of research might well benefit from their findings, in that devices similar to the one the scientists developed to fabricate single photon sources could also provide nonlinearities at the low photon count scale. This capability could in turn allow the implementation of deterministic quantum gates, a new optical quantum computing paradigm in which reversible quantum logic gates – for example, Toffoli or CNOT (controlled NOT) gates– can simulate irreversible classical logic gates, thereby allowing quantum computers to perform any computation which can be performed by a classical deterministic computer. “Single photons can also be used to probe the mechanical modes of mechanical resonator and develop quantum sensing with macroscopic objects. Other applications,” she concludes, “could benefit from the possibility to have very efficient single photon sources, such as an imaging system with single photon sources that could allow dramatically increased imaging sensitivity. Such technique could have applications in biology where the lower the photon flux, the better for exploring in vivo samples.” “Indeed, for the photons to be fully indistinguishable, the emitter should be highly isolated from any source of decoherence induced by the solid-state environment. However, our study showed that collisions of the carriers with phonons and fluctuation of charges around the quantum dot were the main limitations.” To solve this problem, the scientists added an electrical control to the device3, such that the application of an electric field stabilized the charges around the quantum dot by sweeping out any free charge. This in turn removed the noise. Moreover, she adds, this electrical control allows tuning the quantum dot wavelength – a process that was previously done by increasing temperature at the expense of increasing vibration. “I’d like to underline here that the technology described above is unique worldwide,” Senellart stresses. “Our group is the only one with such full control of all of the quantum dot properties. That is, we control emission wavelength, emission lifetime and coupling to the environment, all in a fully deterministic and scalable way.”Specifically, implementing control of the charge environment for quantum dots in connected pillar cavities, and applying an electric field on a cavity structure optimally coupled to a quantum dot, required significant attention. “We had strong indications back in 2013 that the indistinguishability of our photons was limited by some charge fluctuations around the quantum dot: Even in the highest-quality semiconductors, charges bound to defects fluctuate and create a fluctuating electric field. In the meantime, several colleagues were observing very low charge noise in structures where an electric field was applied to the quantum dot – but this was not combined with a cavity structure.” The challenge, Senellart explains, was to define a metallic contact on a microcavity (which is typically a cylinder with a diameter of 2-3 microns) without covering the pillar’s top surface.”We solved this problem by proposing a new kind of cavity – that is, we showed that we can actually connect the cylinder to a bigger frame using some one-dimensional bridges without modifying too much the confinement of the optical field.” This geometry, which the researchers call connected pillars, allows having the same optical confinement as an isolated pillar while defining the metallic contact far from the pillar itself. Senellart says that the connected pillars geometry was the key to both controlling the quantum wavelength of dot and efficiently collecting its emission3.In demonstrating the efficient generation of a pure single photon with near-unity indistinguishability, Senellart continues, the researchers had one last step – combining high photon extraction efficiency and perfect indistinguishability – which they did by implementing a resonant excitation scheme of the quantum dot. “In 2013, Prof. Chao-Yang Lu’s team in Hefei, China showed that one could obtain photons with 96% indistinguishability by exciting the quantum dot state in a strictly resonant way4. Their result was beautiful, but again, not combined with an efficient extraction of the photons. The experimental challenge here is to suppress the scattered light from the laser and collect only the single photons radiated by the quantum dot.” This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. , Nature Physicslast_img read more

£4 million safety works ordered after these huge cracks appeared on this

first_imgGet the biggest Daily stories by emailSubscribeSee our privacy noticeThank you for subscribingSee our privacy noticeCould not subscribe, try again laterInvalid EmailMulti-million pound safety works have been ordered to stop part of a road subsiding onto the busy West Coast Main Line. Network Rail is spending £4 million on the project to stabilise West Parade, in Fenton, after huge cracks appeared along the side of the crumbling road. It has already spent £700,000 by digging up the top two metres of the embankment and replacing it with reinforced earth, installing a new 70-metre long wall and fence, and resurfacing the carriageway to eliminate the cracks. It follows residents and motorists complaining about the state of the road for years. The resurfaced West Parade, in Fenton Neighbour Paul Frost, aged 62, said: “The road was in a bad state and if you drove down it you could feel yourself go down on one side.” Read MoreTop stories on StokeonTrentLive Driver named following fatal collision Dad slams ‘disgusting’ hospital window One of the cracks on West Parade, Fenton Now Network Rail is to carry out further work at track level within the next two years as part of the project. Network Rail route asset manager Tony Butler said: “West Parade’s road surface was showing visible signs of movement. We had to act quickly to maintain access for residents as well as protect the West Coast Main Line below – the busiest mixed-use railway in Europe. “A second phase of work is due to take place at track level within the next two years to secure the long-term stability of the site.” The safety improvement works on West Parade, Fenton Residents have told how they thought their vehicles were sloping towards the railway tracks when they drove along West Parade. Read More’Ken’s really enjoying the new lido!’ – Campaigning Desiree snaps these ingenious photos to highlight HUGE potholes on her estate   Carol Walters, aged 71, of West Parade, said: “The road was horrendous before and properly sloped towards the drop. It was scary because it was gradually getting worse. “The road had been cracked for about five years and if you were driving towards Stoke, you could feel the slope in the road, and it felt like you had nothing to hold on to. Now it’s level, it’s great.” Police search for missing woman Want to tell us about something going on where you live? Let us know – Tweet us  @SOTLive  or message us on  our Facebook page. And if you have pictures to share, tag us on Instagram at  StokeonTrentLive. Punter found hiding in bushes last_img read more