Tag Archives: computing

ight behaves both as a particle and as a wave. Since the days of Einstein, scientists have been trying to directly observe both of these aspects of light at the same time. Now, scientists at EPFL have succeeded in capturing the first-ever snapshot of this dual behavior.
Credit:EPFL

Entering 2016 with new hope

Syed Faisal ur Rahman


 

Year 2015 left many good and bad memories for many of us. On one hand we saw more wars, terrorist attacks and political confrontations, and on the other hand we saw humanity raising voices for peace, sheltering refugees and joining hands to confront the climate change.

In science, we saw first ever photograph of light as both wave and particle. We also saw some serious development in machine learning, data sciences and artificial intelligence areas with some voices raising caution about the takeover of AI over humanity and issues related to privacy. The big question of energy and climate change remained a key point of  discussion in scientific and political circles. The biggest break through came near the end of the year with Paris deal during COP21.

The deal involving around 200 countries represent a true spirit of humanity to limit global warming below 2C and commitments for striving to keep temperatures at above 1.5C pre-industrial levels. This truly global commitment also served in bringing rival countries to sit together for a common cause to save humanity from self destruction. I hope the spirit will continue in other areas of common interest as well.

This spectacular view from the NASA/ESA Hubble Space Telescope shows the rich galaxy cluster Abell 1689. The huge concentration of mass bends light coming from more distant objects and can increase their total apparent brightness and make them visible. One such object, A1689-zD1, is located in the box — although it is still so faint that it is barely seen in this picture. New observations with ALMA and ESO’s VLT have revealed that this object is a dusty galaxy seen when the Universe was just 700 million years old. Credit: NASA; ESA; L. Bradley (Johns Hopkins University); R. Bouwens (University of California, Santa Cruz); H. Ford (Johns Hopkins University); and G. Illingworth (University of California, Santa Cruz)
This spectacular view from the NASA/ESA Hubble Space Telescope shows the rich galaxy cluster Abell 1689. The huge concentration of mass bends light coming from more distant objects and can increase their total apparent brightness and make them visible. One such object, A1689-zD1, is located in the box — although it is still so faint that it is barely seen in this picture.
New observations with ALMA and ESO’s VLT have revealed that this object is a dusty galaxy seen when the Universe was just 700 million years old.
Credit:
NASA; ESA; L. Bradley (Johns Hopkins University); R. Bouwens (University of California, Santa Cruz); H. Ford (Johns Hopkins University); and G. Illingworth (University of California, Santa Cruz)

Space Sciences also saw some enormous advancements with New Horizon sending photographs from Pluto, SpaceX successfully landed the reusable Falcon 9 rocket back after a successful launch and we also saw the discovery of the largest regular formation in the Universe,by Prof Lajos Balazs, which is a ring of nine galaxies 7 billion light years away and 5 billion light years wide covering a third of our sky.We also learnt this year that Mars once had more water than Earth’s Arctic Ocean. NASA later confirmed the evidence that water flows on the surface of Mars. The announcement led to some interesting insight into the atmospheric studies and history of the red planet.

In the researchers' new system, a returning beam of light is mixed with a locally stored beam, and the correlation of their phase, or period of oscillation, helps remove noise caused by interactions with the environment. Illustration: Jose-Luis Olivares/MIT
In the researchers’ new system, a returning beam of light is mixed with a locally stored beam, and the correlation of their phase, or period of oscillation, helps remove noise caused by interactions with the environment.
Illustration: Jose-Luis Olivares/MIT

We also saw some encouraging advancements in neurosciences where we saw MIT’s researchers  developing a technique allowing direct stimulation of neurons, which could be an effective treatment for a variety of neurological diseases, without the need for implants or external connections. We also saw researchers reactivating neuro-plasticity in older mice, restoring their brains to a younger state and we also saw some good progress in combating Alzheimer’s diseases.

Quantum physics again stayed as a key area of scientific advancements. Quantu

ight behaves both as a particle and as a wave. Since the days of Einstein, scientists have been trying to directly observe both of these aspects of light at the same time. Now, scientists at EPFL have succeeded in capturing the first-ever snapshot of this dual behavior. Credit:EPFL
ight behaves both as a particle and as a wave. Since the days of Einstein, scientists have been trying to directly observe both of these aspects of light at the same time. Now, scientists at EPFL have succeeded in capturing the first-ever snapshot of this dual behavior.
Credit:EPFL

m computing is getting more closer to become a viable alternative to current architecture. The packing of the single-photon detectors on an optical chip is a crucial step toward quantum-computational circuits. Researchers at the Australian National University (ANU)  performed experiment to prove that reality does not exist until it is measured.

There are many other areas where science and technology reached new heights and will hopefully continue to do so in the year 2016. I hope these advancements will not only help us in growing economically but also help us in becoming better human beings and a better society.

 

 

 

 

 

Illustration of superconducting detectors on arrayed waveguides on a photonic integrated circuit for detection of single photons.

Credit: F. Najafi/ MIT

Toward quantum chips

Packing single-photon detectors on an optical chip is a crucial step toward quantum-computational circuits.

By Larry Hardesty


CAMBRIDGE, Mass. – A team of researchers has built an array of light detectors sensitive enough to register the arrival of individual light particles, or photons, and mounted them on a silicon optical chip. Such arrays are crucial components of devices that use photons to perform quantum computations.

Single-photon detectors are notoriously temperamental: Of 100 deposited on a chip using standard manufacturing techniques, only a handful will generally work. In a paper appearing today in Nature Communications, the researchers at MIT and elsewhere describe a procedure for fabricating and testing the detectors separately and then transferring those that work to an optical chip built using standard manufacturing processes.

Illustration of superconducting detectors on arrayed waveguides on a photonic integrated circuit for detection of single photons. Credit: F. Najafi/ MIT
Illustration of superconducting detectors on arrayed waveguides on a photonic integrated circuit for detection of single photons.
Credit: F. Najafi/ MIT

In addition to yielding much denser and larger arrays, the approach also increases the detectors’ sensitivity. In experiments, the researchers found that their detectors were up to 100 times more likely to accurately register the arrival of a single photon than those found in earlier arrays.

“You make both parts — the detectors and the photonic chip — through their best fabrication process, which is dedicated, and then bring them together,” explains Faraz Najafi, a graduate student in electrical engineering and computer science at MIT and first author on the new paper.

Thinking small

According to quantum mechanics, tiny physical particles are, counterintuitively, able to inhabit mutually exclusive states at the same time. A computational element made from such a particle — known as a quantum bit, or qubit — could thus represent zero and one simultaneously. If multiple qubits are “entangled,” meaning that their quantum states depend on each other, then a single quantum computation is, in some sense, like performing many computations in parallel.

With most particles, entanglement is difficult to maintain, but it’s relatively easy with photons. For that reason, optical systems are a promising approach to quantum computation. But any quantum computer — say, one whose qubits are laser-trapped ions or nitrogen atoms embedded in diamond — would still benefit from using entangled photons to move quantum information around.

“Because ultimately one will want to make such optical processors with maybe tens or hundreds of photonic qubits, it becomes unwieldy to do this using traditional optical components,” says Dirk Englund, the Jamieson Career Development Assistant Professor in Electrical Engineering and Computer Science at MIT and corresponding author on the new paper. “It’s not only unwieldy but probably impossible, because if you tried to build it on a large optical table, simply the random motion of the table would cause noise on these optical states. So there’s been an effort to miniaturize these optical circuits onto photonic integrated circuits.”

The project was a collaboration between Englund’s group and the Quantum Nanostructures and Nanofabrication Group, which is led by Karl Berggren, an associate professor of electrical engineering and computer science, and of which Najafi is a member. The MIT researchers were also joined by colleagues at IBM and NASA’s Jet Propulsion Laboratory.

Relocation

The researchers’ process begins with a silicon optical chip made using conventional manufacturing techniques. On a separate silicon chip, they grow a thin, flexible film of silicon nitride, upon which they deposit the superconductor niobium nitride in a pattern useful for photon detection. At both ends of the resulting detector, they deposit gold electrodes.

Then, to one end of the silicon nitride film, they attach a small droplet of polydimethylsiloxane, a type of silicone. They then press a tungsten probe, typically used to measure voltages in experimental chips, against the silicone.

“It’s almost like Silly Putty,” Englund says. “You put it down, it spreads out and makes high surface-contact area, and when you pick it up quickly, it will maintain that large surface area. And then it relaxes back so that it comes back to one point. It’s like if you try to pick up a coin with your finger. You press on it and pick it up quickly, and shortly after, it will fall off.”

With the tungsten probe, the researchers peel the film off its substrate and attach it to the optical chip.

In previous arrays, the detectors registered only 0.2 percent of the single photons directed at them. Even on-chip detectors deposited individually have historically topped out at about 2 percent. But the detectors on the researchers’ new chip got as high as 20 percent. That’s still a long way from the 90 percent or more required for a practical quantum circuit, but it’s a big step in the right direction.

Source: MIT News Office

In a pioneering study, Professor Menon and his team were able to discover half-light, half-matter particles in atomically thin semiconductors (thickness ~ a millionth of a single sheet of paper) consisting of two-dimensional (2D) layer of molybdenum and sulfur atoms arranged similar to graphene. They sandwiched this 2D material in a light trapping structure to realize these composite quantum particles.

Credit: CCNY

Study Unveils New Half-Light Half-Matter Quantum Particles

Prospects of developing computing and communication technologies based on quantum properties of light and matter may have taken a major step forward thanks to research by City College of New York physicists led by Dr. Vinod Menon.

In a pioneering study, Professor Menon and his team were able to discover half-light, half-matter particles in atomically thin semiconductors (thickness ~ a millionth of a single sheet of paper) consisting of two-dimensional (2D) layer of molybdenum and sulfur atoms arranged similar to graphene. They sandwiched this 2D material in a light trapping structure to realize these composite quantum particles.

“Besides being a fundamental breakthrough, this opens up the possibility of making devices which take the benefits of both light and matter,” said Professor Menon.  

In a pioneering study, Professor Menon and his team were able to discover half-light, half-matter particles in atomically thin semiconductors (thickness ~ a millionth of a single sheet of paper) consisting of two-dimensional (2D) layer of molybdenum and sulfur atoms arranged similar to graphene. They sandwiched this 2D material in a light trapping structure to realize these composite quantum particles. Credit: CCNY
In a pioneering study, Professor Menon and his team were able to discover half-light, half-matter particles in atomically thin semiconductors (thickness ~ a millionth of a single sheet of paper) consisting of two-dimensional (2D) layer of molybdenum and sulfur atoms arranged similar to graphene. They sandwiched this 2D material in a light trapping structure to realize these composite quantum particles.
Credit: CCNY

For example one can start envisioning logic gates and signal processors that take on best of light and matter. The discovery is also expected to contribute to developing practical platforms for quantum computing. 

Dr. Dirk Englund, a professor at MIT whose research focuses on quantum technologies based on semiconductor and optical systems, hailed the City College study.

“What is so remarkable and exciting in the work by Vinod and his team is how readily this strong coupling regime could actually be achieved. They have shown convincingly that by coupling a rather standard dielectric cavity to exciton–polaritons in a monolayer of molybdenum disulphide, they could actually reach this strong coupling regime with a very large binding strength,” he said. 

Professor Menon’s research team included City College PhD students, Xiaoze Liu, Tal Galfsky and Zheng Sun, and scientists from Yale University, National Tsing Hua University (Taiwan) and Ecole Polytechnic -Montreal (Canada).

The study appears in the January issue of the journal “Nature Photonics.” It was funded by the U.S. Army Research Laboratory’s Army Research Office and the National Science Foundation through the Materials Research Science and Engineering Center – Center for Photonic and Multiscale Nanomaterials. 

Source: The City College New of York

Islamic Republic of Pakistan to become Associate Member State of CERN: CERN Press Release

Geneva 19 December 2014. CERN1 Director General, Rolf Heuer, and the Chairman of the Pakistan Atomic Energy Commission, Ansar Parvez, signed today in Islamabad, in presence of Prime Minister Nawaz Sharif, a document admitting the Islamic Republic of Pakistan to CERN Associate Membership, subject to ratification by the Government of Pakistan.

“Pakistan has been a strong participant in CERN’s endeavours in science and technology since the 1990s,” said Rolf Heuer. “Bringing nations together in a peaceful quest for knowledge and education is one of the most important missions of CERN. Welcoming Pakistan as a new Associate Member State is therefore for our Organization a very significant event and I’m looking forward to enhanced cooperation with Pakistan in the near future.”

“It is indeed a historic day for science in Pakistan. Today’s signing of the agreement is a reward for the collaboration of our scientists, engineers and technicians with CERN over the past two decades,” said Ansar Parvez. “This Membership will bring in its wake multiple opportunities for our young students and for industry to learn and benefit from CERN. To us in Pakistan, science is not just pursuit of knowledge, it is also the basic requirement to help us build our nation.”

The Islamic Republic of Pakistan and CERN signed a Co-operation Agreement in 1994. The signature of several protocols followed this agreement, and Pakistan contributed to building the CMS and ATLAS experiments. Pakistan contributes today to the ALICE, ATLAS, CMS and LHCb experiments and operates a Tier-2 computing centre in the Worldwide LHC Computing Grid that helps to process and analyse the massive amounts of data the experiments generate. Pakistan is also involved in accelerator developments, making it an important partner for CERN.

The Associate Membership of Pakistan will open a new era of cooperation that will strengthen the long-term partnership between CERN and the Pakistani scientific community. Associate Membership will allow Pakistan to participate in the governance of CERN, through attending the meetings of the CERN Council. Moreover, it will allow Pakistani scientists to become members of the CERN staff, and to participate in CERN’s training and career-development programmes. Finally, it will allow Pakistani industry to bid for CERN contracts, thus opening up opportunities for industrial collaboration in areas of advanced technology.

Footnote(s)

1. CERN, the European Organization for Nuclear Research, is the world’s leading laboratory for particle physics. It has its headquarters in Geneva. At present, its Member States are Austria, Belgium, Bulgaria, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Israel, Italy, the Netherlands, Norway, Poland, Portugal, Slovakia, Spain, Sweden, Switzerland and the United Kingdom. Romania is a Candidate for Accession. Serbia is an Associate Member in the pre-stage to Membership. India, Japan, the Russian Federation, the United States of America, Turkey, the European Union, JINR and UNESCO have Observer Status.

Source : CERN

Characteristics of a universal simulator|Study narrows the scope of research on quantum computing

Despite a lot of work being done by many research groups around the world, the field of Quantum computing is still in its early stages. We still need to cover a lot of grounds to achieve the goal of developing a working Quantum computer capable of doing the tasks which are expected or predicted. Recent research by a SISSA led team has tried to give the future research in the area of Quantum computing some direction based on the current state of research in the area.


“A quantum computer may be thought of as a ‘simulator of overall Nature,” explains Fabio Franchini, a researcher at the International School for Advanced Studies (SISSA) of Trieste, “in other words, it’s a machine capable of simulating Nature as a quantum system, something that classical computers cannot do”. Quantum computers are machines that carry out operations by exploiting the phenomena of quantum mechanics, and they are capable of performing different functions from those of current computers. This science is still very young and the systems produced to date are still very limited. Franchini is the first author of a study just published in Physical Review Xwhich establishes a basic characteristic that this type of machine should possess and in doing so guides the direction of future research in this field.

The study used analytical and numerical methods. “What we found” explains Franchini, “is that a system that does not exhibit ‘Majorana fermions’ cannot be a universal quantum simulator”. Majorana fermions were hypothesized by Ettore Majorana in a paper published 1937, and they display peculiar characteristics: a Majorana fermion is also its own antiparticle. “That means that if Majorana fermions meet they annihilate among themselves,” continues Franchini. “In recent years it has been suggested that these fermions could be found in states of matter useful for quantum computing, and our study confirms that they must be present, with a certain probability related to entanglement, in the material used to build the machine”.

Entanglement, or “action at a distance”, is a property of quantum systems whereby an action done on one part of the system has an effect on another part of the same system, even if the latter has been split into two parts that are located very far apart. “Entanglement is a fundamental phenomenon for quantum computers,” explains Franchini.

“Our study helps to understand what types of devices research should be focusing on to construct this universal simulator. Until now, given the lack of criteria, research has proceeded somewhat randomly, with a huge consumption of time and resources”.

The study was conducted with the participation of many other international research institutes in addition to SISSA, including the Massachusetts Institute of Technology (MIT) in Boston, the University of Oxford and many others.

More in detail…

“Having a quantum computer would open up new worlds. For example, if we had one today we would be able to break into any bank account,” jokes Franchini. “But don’t worry, we’re nowhere near that goal”.

At the present time, several attempts at quantum machines exist that rely on the properties of specific materials. Depending on the technology used, these computers have sizes varying from a small box to a whole room, but so far they are only able to process a limited number of information bits, an amount infinitely smaller than that processed by classical computers.

However, it’s not correct to say that quantum computers are, or will be, more powerful than traditional ones, points out Franchini. “There are several things that these devices are worse at. But, by exploiting quantum mechanics, they can perform operations that would be impossible for classical computers”.

Source: International School of Advanced Studies (SISSA)

 

Magnetic states at oxide interfaces controlled by electricity. Top image show magnetic state with -3 volts applied, and bottom image shows nonmagnetic state with 0 volts applied. Credit: University of Pittsburgh

New Discovery Could Pave the Way for Spin-based Computing

Novel oxide-based magnetism follows electrical commands

PITTSBURGH—Electricity and magnetism rule our digital world. Semiconductors process electrical information, while magnetic materials enable long-term data storage. A University of Pittsburgh research team has discovered a way to fuse these two distinct properties in a single material, paving the way for new ultrahigh density storage and computing architectures.

Whilephones and laptops rely on electricity to process and temporarily store information, long-term data storage is still largely achieved via magnetism. Discs coated with magnetic material are locally oriented (e.g. North or South to represent “1” and “0”), and each independent magnet can be used to store a single bit of information. However, this information is not directly coupled to the semiconductors used to process information. Having a magnetic material that can store and process information would enable new forms of hybrid storage and processing capabilities.Such a material has been created by the Pitt research team led by Jeremy Levy, a Distinguished Professor of Condensed Matter Physics in Pitt’s Kenneth P. Dietrich School of Arts and Sciences and director of the Pittsburgh Quantum Institute.

Magnetic states at oxide interfaces controlled by electricity. Top image show magnetic state with -3 volts applied, and bottom image shows nonmagnetic state with 0 volts applied. Credit: University of Pittsburgh
Magnetic states at oxide interfaces controlled by electricity. Top image show magnetic state with -3 volts applied, and bottom image shows nonmagnetic state with 0 volts applied. Credit: University of Pittsburgh

Levy, other researchers at Pitt, and colleagues at the University of Wisconsin-Madison today published their work in Nature Communications, elucidating their discovery of a form of magnetism that can be stabilized with electric fields rather than magnetic fields. The University of Wisconsin-Madision researchers were led by Chang-Beom Eom, the Theodore H. Geballe Professor and Harvey D. Spangler Distinguished Professor in the Department of Materials Science and Engineering. Working with a material formed from a thick layer of one oxide—strontium titanate—and a thin layer of a second material—lanthanum aluminate—these researchers have found that the interface between these materials can exhibit magnetic behavior that is stable at room temperature. The interface is normally conducting, but by “chasing” away the electrons with an applied voltage (equivalent to that of two AA batteries), the material becomes insulating and magnetic. The magnetic properties are detected using “magnetic force microscopy,” an imaging technique that scans a tiny magnet over the material to gauge the relative attraction or repulsion from the magnetic layer.

The newly discovered magnetic properties come on the heels of a previous invention by Levy, so-called “Etch-a-Sketch Nanoelectronics” involving the same material. The discovery of magnetic properties can now be combined with ultra-small transistors, terahertz detectors, and single-electron devices previously demonstrated.

“This work is indeed very promising and may lead to a new type of magnetic storage,” says Stuart Wolf, head of the nanoSTAR Institute at the University of Virginia. Though not an author on this paper, Wolf is widely regarded as a pioneer in the area of spintronics.

“Magnetic materials tend to respond to magnetic fields and are not so sensitive to electrical influences,” Levy says. “What we have discovered is that a new family of oxide-based materials can completely change its behavior based on electrical input.”

This discovery was supported by grants from the National Science Foundation, the Air Force Office of Scientific Research, and the Army Research Office.

Source: University of Pittsburgh News