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Researchers engineer molecular magnets to act as longlived qubits

first_img(PhysOrg.com) — Some physicists today are investigating the possibility of using molecular magnets as information storage units in future quantum computers. Molecular magnets are molecules whose magnetic moments prefer to lie along a particular axis with respect to the molecular structure. They have electron spin structures that can be magnetically tuned to more than one state and, at low temperatures, can retain this state even in the absence of a magnetic field, potentially allowing them to store information. More information: C.J. Wedge, et al. “Chemical Engineering of Molecular Qubits.” PRL 108, 107204 (2012). DOI: 10.1103/PhysRevLett.108.107204 Chemical structure of a molecular magnet. Image credit: C.J. Wedge, et al. ©2012 American Physical Society Copyright 2012 PhysOrg.com. All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com. Citation: Researchers engineer molecular magnets to act as long-lived qubits (2012, March 21) retrieved 18 August 2019 from https://phys.org/news/2012-03-molecular-magnets-long-lived-qubits.html Explore further 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. Breakthrough in quantum computing: Resisting ‘quantum bug’ Now a team of researchers from the UK have demonstrated that the phase of quantum mechanical superpositions between the magnetic states can last for more than 15 microseconds, allowing their spin states to be repeatedly switched before they lose their information through decoherence. This finding adds to the evidence that molecular magnets may be useful as qubits, the components of a quantum computer.The researchers, C.J. Wedge, et al., from the University of Oxford and the University of Manchester, have published their study on how to chemically engineer molecular qubits to increase their phase memory times in a recent issue of Physical Review Letters. Previously, the researchers achieved a phase memory time of 3.8 microseconds, and studies of other molecular magnet systems have yielded times on the 1 microsecond time scale.  “Phase memory time and coherence time are very similar concepts,” coauthor Arzhang Ardavan of the University of Oxford told PhysOrg.com. “[Long phase memory time] means that it is possible to manipulate the qubit many times before the quantum information is lost. That is the greatest significance, but we were also pleased that it was possible to control the molecular structures precisely so as to determine the various decoherence mechanisms and to reduce them as far as we were able.”In their study, the researchers focused on Cr7Ni molecular magnets, which they had previously shown to have  coherence times that greatly exceed the 10 nanoseconds needed for single-qubit manipulations. Here, they have taken the next steps and investigated the specific sources of the molecular magnet’s decoherence (nuclear spin diffusion and spectral diffusion), as well as how to optimize the structures to delay decoherence as long as possible.To do this, the researchers compared different Cr7Ni structures by changing two key components, certain cations and ligands. They specifically investigated how well the different structures retained their spin states at low temperatures, as measured by the structures’ phase-coherence relaxation time. The researchers found that optimally engineered Cr7Ni molecular magnets can have phase memory times exceeding 15 microseconds, which is several orders of magnitude higher than the time required for single-qubit manipulations, and significantly longer than previous demonstrations.The researchers predict that the results will lead to the ability to manipulate quantum states within molecular magnet clusters. They plan to further investigate ways to manipulate molecular magnets in the future.“We will examine various possibilities,” Ardavan said. “Our collaborators who work on the chemistry of these molecules are able to synthesize structures incorporating several coupled molecular magnets. We will work on simple multi-qubit algorithms using these kinds of molecules. “Recently, it was proposed theoretically that electric fields could be used to manipulate the magnetic states of molecular magnets,” he added. “We are examining these possibilities experimentally.”last_img read more

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Observations uncover details about the open cluster IC 4996

first_img Citation: Observations uncover details about the open cluster IC 4996 (2019, February 13) retrieved 18 August 2019 from https://phys.org/news/2019-02-uncover-cluster-ic.html Using the Vatican Advanced Technology Telescope (VATT) and data from ESA’s Gaia satellite, astronomers have conducted a new study of the young open cluster IC 4996 and its vicinity. The research, presented in a paper published January 31 on arXiv.org, reports more details about properties of this cluster. IC 4996 is a young open cluster in the constellation Cygnus, believed to be a member of an OB association known as Cygnus OB1 (or Cyg OB1), Although numerous observations of IC 4996 have been performed to date, its distance and age remain uncertain. Some studies suggest that it is located about 5,400 light years away from the Earth, while other papers estimate that it may reside as much as 2,400 light years farther. Similarly, its age estimates range from 6 million to 9 million years in various studies.In order to resolve these discrepancies and to learn more about the nature of IC 4996, a group of astronomers led by Vytautas Straizys of Vilnius University, Lithuania, conducted their own study of this cluster. For this purpose, they used the 1.8-meter VATT telescope located on Mt. Graham, Arizona, and data from Gaia’s Data Release 2 (DR2). Published in April 2018, DR2 contains high-precision measurements, including positions in the sky, parallaxes and proper motions for more than 1 billion sources in the Milky Way galaxy. Such information is crucial for determining distances and ages of stars more accurately.”In this article, we attempt to determine the parameters of IC 4996 with new spectroscopic MK types of the brightest stars and two-dimensional photometric spectral types of fainter stars based on their CCD photometry in the Vilnius system and individual dereddening,” the astronomers wrote in the paper.The study reveals that the Gaia parallax of IC 4996 is 0.522 mas, which corresponds to a distance of 6,243 light years. The age of the cluster was estimated to be between 8 million and 10 million years.Given that the distance to Cyg OB1 is known to be about 5,483 light years, the researchers noted that IC 4996 is most likely not a member of this association. However, they added that this cluster more likely has a common origin with the Cygnus OB3 (Cyg OB3) association, which is located between 5,870 and 6,500 light years away.Furthermore, the research found that the interstellar extinction (dimming due to the presence of dust in the interstellar medium) of IC 4996 covers a wide range of values, from 1.3 to 2.4 mag, while the mean value in the central part of the cluster is 1.8 mag. The authors of the paper also noted that DR2 dataset allowed them to identify 72 new possible cluster members.In concluding remarks, Straizys’ team emphasized that their research proves that a two-dimensional classification of stars based on multicolor photometry, together with astrometry from Gaia, can be applied for obtaining physical parameters of open clusters. According to the researchers, the study also shows that boundaries of stellar associations should be revised. Open cluster IC 4996. Credit: Peter Wienerroither. Astronomers investigate open cluster NGC 6530 © 2019 Science X Network Explore further More information: V. Straižys et al. Young open cluster IC 4996 and its vicinity: multicolor photometry and Gaia DR2 astrometry. arXiv:1901.11375 [astro-ph.GA]. arxiv.org/abs/1901.11375 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.last_img read more

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Are women really moving up in the workplace

first_imgMeanwhile, men were significantly more sanguine about progress: 33 percent said they’ve seen positive change in the last five years. Only 20 percent of women agreed things have gotten better for women in their companies in the last five years, according to a new ASCEND-Morning Consult poll. The #MeToo movement has thrown a spotlight on gender discrimination issues in the workplace. But is office culture really changing? It depends on whom you ask.center_img “We were actually quite surprised,” Katherine Phillips, a Columbia Business School professor who analyzed the poll’s results for Ascend and Morning Consult, told “Morning Joe” co-host and Know Your Value founder Mika Brzezinski. Read the whole story: NBClast_img read more

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Hills to soon get slew of new tourist spots says Goutam Deb

first_imgDarjeeling: Darjeeling is all set to get a number of new tourist spots along with the revamping of existing tourist facilities. The new tourist facilities, including a location for destination weddings, is also being developed by the state Tourism department.State Tourism minister Goutam Deb, while on a two day tour of the Darjeeling Hills, stated that a number of key tourism projects are on the anvil. A high-end property will be developed by the Tourism department at Dhotoreah below Rongbul. “It is an abandoned tea garden land. We will reclaim around 25 acres for this project. It is a beautiful flat land which offers a 360 degree view. We will have high-end cottages, a multi-purpose hall where destination weddings can be held, a walk trail and a helipad. We will renovate the 5km long access road to this property,” said Deb. Also Read – Rain batters Kolkata, cripples normal lifeThe Darjeeling Tourist Lodge is also being revamped, at a cost of around Rs 25 crore. “6 architects have been shortlisted from 14. They will be redesigning the tourist lodge. They are scheduled to hand in the drawings soon. Tenders will be called once the drawings are finalised,” said the minister. The revamped tourist lodge will boast of a state-of-the-art lobby, rooftop restaurant, bar, a landscaped lawn and more than 40 rooms. The Kurseong Tourist Lodge will also be revamped, with expansion of the property also on the cards. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killed”There is a property below the Kurseong Tourist Lodge, which can be used to expand the existing building. We will renovate the rooms, include a modular kitchen, renovate the restaurant, add a deck and landscape the surrounding areas,” Deb said. The 140 year old Botanical garden in Darjeeling is all set to get a major facelift as well. After visiting the garden on Friday morning, the minister stated: “The garden is of immense importance to students, researchers and tourists from all over the world. It has thousands of species of plants, especially of Himalayan origin. The Tourism department and the Forest department will be working together to give it a facelift. A DPR is being prepared.” The roads and drains inside the sprawling garden will all be revamped, along with the green house. A new tourist destination point will come up on an acre of land adjoining the garden. In Kalimpong, Hill Top and Morgan House will be revamped, along with a new property that will be built in Delo. In Tiger Hill, Tonglu and Phalut, trekker huts will be built. “These will be tent-type accommodations with semi permanent light construction. At each destination, the cost of construction will be around Rs 8 crore. We are also rebuilding the old British bungalow at Tiger Hill that was torched during the 1986 agitation,” said Deb. New properties are also coming up at Mongpu, Jhalong and Chalsa.last_img read more

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iOS or Android Choosing the Best Platform For Your Mobile App

first_img Opinions expressed by Entrepreneur contributors are their own. If you’re an aspiring mobile app entrepreneur, your first big decision is which operating system to develop your application for: Apple’s iOS or Google’s Android.The two combined own more than 90 percent market share in the smartphone category, making them the preferred platforms. But while major brands like Yahoo and Twitter have launched iOS apps first, Android is now dominating the smartphone race in the U.S. with 53 percent market share, compared to 36 percent for iOS, according to comScore’s latest report. So how do you decide which platforms to adopt to build your mobile app? Here are three factors to help you make the right decision for your app venture:Revenues versus visibilityAndroid offers the most visibility based on absolute market share numbers, yet according to the latest Distimo survey, 73 percent of all app revenue was generated in Apple’s App Store as compared to only 23 percent for Google Play.But while Apple’s daily app sales revenue is nearly five times that of Google’s, choosing different game plans for each platform can help you maximize your exposure. For example, Whatsapp, one of the most popular messaging apps, is available for free for the first year on the Android platform to gain massive traction and is at $0.99 on the iOS for monetization.You need to craft a strategy that should strike a balance between visibility and revenues. After all, the more visibility you get, the greater your chances of monetization.Take advantage of fragmentationIt is a known fact that developing for Android is no easy task given the more than 400 types of handsets that need to be planned for when programming. Apple has so far been on the positive side of the curve with only four different types of iPhones and iPads. However, with the introduction of iOS 7, Apple is also going down the fragmentation route, offering different features for different handsets.So for example, if your solution integrates the latest AirDrop feature of iOS7, it will not be available to people owning iPhone 3GS, 4, 4S, but only to iPhone 5 users. That’s why it’s important for you to create a solution that caters to a specific OS, especially in the case of Android phones where the segmentation of the OS is far greater among different handsets.Features available in the latest OS of Android, which can run only on high-end phones such as the Galaxy S or the Nexus series, will not be available to those phones on the lower end of the spectrum.Understanding what features are supported by the types of operating systems your application intends to leverage would help you target users with a certain range of handsets. For example, if you want to use the voice recognition feature to accept commands, you’d want to leverage Android’s Jelly Bean operating system’s offline voice typing feature.Understand customer usageGoing a step further into customer behavior or usage, determining which platform to develop first should depend on whether your customer is a heavy user of iTunes or Google services such as Maps, Gmail, Calendar or Google Now.For example, GTasks is a task management app that also works in the Google account mode and integrates well with Gmail, Google Calendar and Google Now.Another metric to consider is the “popular app” categories on both of the platforms. For iOS consumers between the ages of 25 and 34, the most popular app category is sports, health and fitness, followed by music, media and entertainment as well as lifestyle and shopping, according to a recent survey by Flurry. On the other hand, some of the most popular Android categories are personalization, entertainment and books and reference, based on a survey by AppBrain. Get as much information about your customer as possible to determine which platform is right for you to start with. Don’t get carried away with media reports that favor one operating system over the other. Go where your customers are. Growing a business sometimes requires thinking outside the box. Register Now » July 17, 2013 Free Webinar | Sept. 9: The Entrepreneur’s Playbook for Going Global 4 min readlast_img read more

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