Friday, January 30, 2015

D-Wave System Raises $29M to Advance Quantum Computer Development

D-Wave Systems Raises an Additional $29M, Closing 2014 Financing at $62M

Burnaby, British Columbia - January 29, 2015 - D-Wave Systems Inc., the world's first quantum computing company, today announced that it has closed $29 million in funding from a large institutional investor, among others. This funding will be used to accelerate development of D-Wave’s quantum hardware and software and expand the software application ecosystem. This investment brings total funding in D-Wave to $174 million (CAD), with approximately $62 million raised in 2014.

[caption id="attachment_556" align="aligncenter" width="620"]D-Wave System Raises $29M to Advance Quantum Computer Development D-Wave System Raises $29M to Advance Quantum Computer Development[/caption]

“The investment is a testament to the progress D-Wave continues to make as the leader in quantum computing systems,” said Vern Brownell, CEO of D-Wave. “The funding we received in 2014 will advance our quantum hardware and software development, as well as our work on leading edge applications of our systems. By making quantum computing available to more organizations, we’re driving our goal of finding solutions to the most complex optimization and machine learning applications in national defense, computing, research and finance.”

The funding follows a year of strong growth and advancement for D-Wave. Highlights include:

•    Significant progress made towards the release of the next D-Wave quantum system featuring a 1000 qubit processor, which is currently undergoing testing in D-Wave’s labs.
•    The company’s patent portfolio grew to over 150 issued patents worldwide, with 11 new U.S. patents being granted in 2014, covering aspects of D-Wave’s processor technology, systems and techniques for solving computational problems using D-Wave’s technology.
•    D-Wave Professional Services launched, providing quantum computing experts to collaborate directly with customers, and deliver training classes on the usage and programming of the D-Wave system to a number of national laboratories, businesses and universities.
•    Partnerships were established with DNA-SEQ and 1QBit, companies that are developing quantum software applications in the spheres of medicine and finance, respectively.
•    Research throughout the year continued to validate D-Wave’s work, including a study showing further evidence of quantum entanglement by D-Wave and USC scientists, published in Physical Review X this past May.

Since 2011, some of the most prestigious organizations in the world, including Lockheed Martin, NASA, Google, USC and the Universities Space Research Association (USRA), have partnered with D-Wave to use their quantum computing systems. In 2015, these partners will continue to work with the D-Wave computer, conducting pioneering research in machine learning, optimization, and space exploration.

D-Wave, which already employs over 120 people, plans to expand hiring with the additional funding. Key areas of growth include research, processor and systems development and software engineering.

About D-Wave Systems Inc.
Founded in 1999, D-Wave Systems is the first quantum computing company. Its mission is to integrate new discoveries in physics, engineering, manufacturing, and computer science into breakthrough approaches to computation to help solve some of the world’s most complex challenges. The company's flagship product, the D-Wave Two™ computer system, is built around a novel type of superconducting processor that uses quantum mechanics to massively accelerate computation.

D-Wave’s customers include some of the world’s most prominent organizations including Lockheed Martin, Google and NASA. With headquarters near Vancouver, Canada, D-Wave U.S. is based in Palo Alto, California. D-Wave has a blue-chip investor base including Bezos Expeditions, BDC Capital, DFJ, Goldman Sachs, Growthworks, Harris & Harris Group, In-Q-Tel, International Investment and Underwriting, and Kensington Partners Limited. For more information, visit:

News Release Source : D-Wave Systems Raises an Additional $29M, Closing 2014 Financing at $62M

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Thursday, January 22, 2015

University of California Scientists Set Quantum Speed Limit

Scientists set quantum speed limit

UC Berkeley, scientists have proved a fundamental relationship between energy and time that sets a “quantum speed limit” on processes ranging from quantum computing and tunneling to optical switching.

[caption id="attachment_547" align="aligncenter" width="482"]University of California Scientists Set Quantum Speed Limit The speed limit, that is, the minimal time to transition between two easily distinguishable states, such as the north and south poles representing up and down states of a quantum spin (top), is characterized by a well-known relationship. But the speed limit between two states not entirely distinguishable, which correspond to states of arbitrary latitude and longitude whether on or within the sphere of all possible states of a quantum spin (bottom), was unknown until two UC Berkeley chemical physicists calculated it.[/caption]

The energy-time uncertainty relationship is the flip side of the Heisenberg uncertainty principle, which sets limits on how precisely you can measure position and speed, and has been the bedrock of quantum mechanics for nearly 100 years. It has become so well-known that it has infected literature and popular culture with the idea that the act of observing affects what we observe.

Not long after German physicist Werner Heisenberg, one of the pioneers of quantum mechanics, proposed his relationship between position and speed, other scientists deduced that energy and time were related in a similar way, implying limits on the speed with which systems can jump from one energy state to another. The most common application of the energy-time uncertainty relationship has been in understanding the decay of excited states of atoms, where the minimum time it takes for an atom to jump to its ground state and emit light is related to the uncertainty of the energy of the excited state.

“This is the first time the energy-time uncertainty principle has been put on a rigorous basis – our arguments don’t appeal to experiment, but come directly from the structure of quantum mechanics,” said chemical physicist K. Birgitta Whaley, director of the Berkeley Quantum Information and Computation Center and a UC Berkeley professor of chemistry. “Before, the principle was just kind of thrown into the theory of quantum mechanics.”

The new derivation of the energy-time uncertainty has application for any measurement involving time, she said, particularly in estimating the speed with which certain quantum processes – such as calculations in a quantum computer – will occur.

“The uncertainty principle really limits how precise your clocks can be,” said first author Ty Volkoff, a graduate student who just received his Ph.D. in chemistry from UC Berkeley. “In a quantum computer, it limits how fast you can go from one state to the other, so it puts limits on the clock speed of your computer.”

The new proof could even affect recent estimates of the computational power of the universe, which rely on the energy-time uncertainty principle.

Volkoff and Whaley included the derivation of the uncertainty principle in a larger paper devoted to a detailed analysis of distinguishable quantum states that appeared online Dec. 18 in the journal Physical Review A.

The problem of precision measurement

Heisenberg’s uncertainty principle, proposed in 1927, states that it’s impossible to measure precisely both the position and speed – or more properly, momentum – of an object. That is, the uncertainty in measurement of the position (∆x) times the uncertainty in measurement of momentum (∆p) will always be greater than or equal to Planck’s constant (∆x∆p > h/4π). Planck’s constant is an extremely small number (6.62606957 × 10-34 square meter-kilogram/second) that describes the graininess of space.

To physicists, an equally useful principle relates the uncertainties of measuring both time and energy: The variance of the energy of a quantum state times the lifetime of the state cannot be less than Planck’s constant (∆E∆t ≥ h/4).

“When students first learn about time-energy uncertainty, they learn about the lifetime of atomic states or emission line widths in spectroscopy, which are very physical but empirical notions,” Volkoff said.

This observed relationship was first addressed mathematically in a 1945 paper by two Russian physicists who dealt only with transitions between two obviously distinct energy states. The new analysis by Volkoff and Whaley applies to all types of experiments, including those in which the beginning and end states may not be entirely distinct. The analysis allows scientists to calculate how long it will take for such states to be distinguishable from one another at any level of certainty.

“In many experiments that examine the time evolution of a quantum state, the experimenters are dealing with endpoints where the states are not completely distinguishable,” Volkoff said. “But you couldn’t determine the minimum time that process would take from our current understanding of the energy-time uncertainty.”

Most experiments dealing with light, as in the fields of spectroscopy and quantum optics, involve states that are not entirely distinct, he said. These states evolve on time scales of the order of femtoseconds – millionths of a billionth of a second.

Alternatively, scientists working on quantum computers aim to establish entangled quantum states that evolve and perform a computation with speeds on the order of nanoseconds.

“Our analysis reveals that a minimal finite length of time must elapse in order to achieve a given success rate for distinguishing an initial quantum state from its time-evolved image using an optimal measurement,” Whaley said.

The new analysis could help determine the times required for quantum tunneling, such as the tunneling of electrons through the band-gap of a semiconductor or the tunneling of atoms in biological proteins.

It also could be useful in a new field called “weak measurement,” which involves tracking small changes in a quantum system, such as entangled qubits in a quantum computer, as the system evolves. No one measurement sees a state that is purely distinct from the previous state.

The work was funded by the National Science Foundation.

News Release Source : Scientists set quantum speed limit

Image Credit : Ty Volkoff Image, UC Berkeley.

Related Information Web Links : Berkeley Quantum Information and Computation Center

Macroscopicity of quantum superpositions on a one-parameter unitary path in Hilbert space

Friday, January 16, 2015

Scientists Build Rice Sized Laser Bodes Well for Quantum Computing

Rice-sized laser, powered one electron at a time, bodes well for quantum computing

Princeton University researchers have built a rice grain-sized laser powered by single electrons tunneling through artificial atoms known as quantum dots. The tiny microwave laser, or "maser," is a demonstration of the fundamental interactions between light and moving electrons.

[caption id="attachment_543" align="aligncenter" width="650"]Scientists Build Rice-Sized Laser Bodes Well for Quantum Computing Scientists Build Rice-Sized Laser Bodes Well for Quantum Computing[/caption]

The researchers built the device -- which uses about one-billionth the electric current needed to power a hair dryer -- while exploring how to use quantum dots, which are bits of semiconductor material that act like single atoms, as components for quantum computers.

"It is basically as small as you can go with these single-electron devices," said Jason Petta, an associate professor of physics at Princeton who led the study, which was published in the journal Science.

The device demonstrates a major step forward for efforts to build quantum-computing systems out of semiconductor materials, according to co-author and collaborator Jacob Taylor, an adjunct assistant professor at the Joint Quantum Institute, University of Maryland-National Institute of Standards and Technology. "I consider this to be a really important result for our long-term goal, which is entanglement between quantum bits in semiconductor-based devices," Taylor said.

The original aim of the project was not to build a maser, but to explore how to use double quantum dots -- which are two quantum dots joined together -- as quantum bits, or qubits, the basic units of information in quantum computers.

"The goal was to get the double quantum dots to communicate with each other," said Yinyu Liu, a physics graduate student in Petta's lab. The team also included graduate student Jiri Stehlik and associate research scholar Christopher Eichler in Princeton's Department of Physics, as well as postdoctoral researcher Michael Gullans of the Joint Quantum Institute.

Because quantum dots can communicate through the entanglement of light particles, or photons, the researchers designed dots that emit photons when single electrons leap from a higher energy level to a lower energy level to cross the double dot.

Each double quantum dot can only transfer one electron at a time, Petta explained. "It is like a line of people crossing a wide stream by leaping onto a rock so small that it can only hold one person," he said. "They are forced to cross the stream one at a time. These double quantum dots are zero-dimensional as far as the electrons are concerned -- they are trapped in all three spatial dimensions."

The researchers fabricated the double quantum dots from extremely thin nanowires (about 50 nanometers, or a billionth of a meter, in diameter) made of a semiconductor material called indium arsenide. They patterned the indium arsenide wires over other even smaller metal wires that act as gate electrodes, which control the energy levels in the dots.

To construct the maser, they placed the two double dots about 6 millimeters apart in a cavity made of a superconducting material, niobium, which requires a temperature near absolute zero, around minus 459 degrees Fahrenheit. "This is the first time that the team at Princeton has demonstrated that there is a connection between two double quantum dots separated by nearly a centimeter, a substantial distance," Taylor said.

When the device was switched on, electrons flowed single-file through each double quantum dot, causing them to emit photons in the microwave region of the spectrum. These photons then bounced off mirrors at each end of the cavity to build into a coherent beam of microwave light.

One advantage of the new maser is that the energy levels inside the dots can be fine-tuned to produce light at other frequencies, which cannot be done with other semiconductor lasers in which the frequency is fixed during manufacturing, Petta said. The larger the energy difference between the two levels, the higher the frequency of light emitted.

Claire Gmachl, who was not involved in the research and is Princeton's Eugene Higgins Professor of Electrical Engineering and a pioneer in the field of semiconductor lasers, said that because lasers, masers and other forms of coherent light sources are used in communications, sensing, medicine and many other aspects of modern life, the study is an important one.

"In this paper the researchers dig down deep into the fundamental interaction between light and the moving electron," Gmachl said. "The double quantum dot allows them full control over the motion of even a single electron, and in return they show how the coherent microwave field is created and amplified. Learning to control these fundamental light-matter interaction processes will help in the future development of light sources."


The paper, "Semiconductor double quantum dot micromaser," was published in the journalScience on Jan. 16, 2015. The research was supported by the David and Lucile Packard Foundation, the National Science Foundation (DMR-1409556 and DMR-1420541), the Defense Advanced Research Projects Agency QuEST (HR0011-09-1-0007), and the Army Research Office (W911NF-08-1-0189).

News Release Source : Rice-sized laser, powered one electron at a time, bodes well for quantum computing

Image Credit : Jason Petta, Department of Physics, Princeton University

Saturday, January 10, 2015

Australian National University Made Quantum Hard Drive Breakthrough

Australian National University Made Quantum Hard Drive Breakthrough

Physicists developing a prototype quantum hard drive have improved storage time by a factor of more than 100.

[caption id="attachment_538" align="aligncenter" width="653"]Australian National University Made Quantum Hard Drive Breakthrough Australian National University Made Quantum Hard Drive Breakthrough[/caption]

The team’s record storage time of six hours is a major step towards a secure worldwide data encryption network based on quantum information, which could be used for banking transactions and personal emails.

“We believe it will soon be possible to distribute quantum information between any two points on the globe,” said lead author Manjin Zhong, from the Research School of Physics and Engineering(RSPE).

“Quantum states are very fragile and normally collapse in milliseconds. Our long storage times have the potential to revolutionise the transmission of quantum information.”

Quantum information promises unbreakable encryption because quantum particles such as photons of light can be created in a way that intrinsically links them. Interactions with either of these entangled particles affect the other, no matter how far they are separated.

The team of physicists at ANU and the University of Otago stored quantum information in atoms of the rare earth element europium embedded in a crystal.

Their solid-state technique is a promising alternative to using laser beams in optical fibres, an approach which is currently used to create quantum networks around 100 kilometres long.

“Our storage times are now so long that it means people need to rethink what is the best way to distribute quantum data,” Ms Zhong said.

“Even transporting our crystals at pedestrian speeds we have less loss than laser systems for a given distance.”

“We can now imagine storing entangled light in separate crystals and then transporting them to different parts of the network thousands of kilometres apart. So, we are thinking of our crystals as portable optical hard drives for quantum entanglement.”


Their research is published in Nature.

Nature have also published a review of the work.

News Release Source : Quantum hard drive breakthrough

Image Credit : Australian National University

Wednesday, January 7, 2015

Atoms Queue up for Quantum Computer Networks

Atoms Queue up for Quantum Computer Networks

QUANTUM NETWORKS - In order to develop future quantum computer networks, it is necessary to hold a known number of atoms and read them without them disappearing. To do this, researchers from the Niels Bohr Institute have developed a method with a trap that captures the atoms along an ultra thin glass fiber, where the atoms can be controlled. The results are published in the scientific journal, Physical Review Letters.

The research is carried out in the quantum optics laboratory in the basement of the Niels Bohr Institute in Copenhagen. The underground laboratory is set back from the road so there are no vibrations from traffic. Here, the researchers have designed experiments in which they can perform ultrasensitive trials with quantum optics.

[caption id="attachment_533" align="aligncenter" width="650"]Atoms Queue up for Quantum Computer Networks Jean Babtiste Béguin and Jürgen Appel in the quantum optics laboratory in the basement of the Niels Bohr Institute, where they did the experiments.[/caption]

“We have an ultra-thin glass fiber with a diameter of half a micrometer (a hundred times smaller than a strand of hair). Along this glass fiber we capture cesium atoms. They are cooled down to 100 micro Kelvin using a laser – this is almost absolute zero, which is equivalent to minus 273 degrees Celsius. This system acts like a trap that holds the atoms on the side of the glass fiber,” explains Jürgen Appel, Associate Professor in the research group Quantop at the Niels Bohr Institute, University of Copenhagen.

Atoms and light linked together

When light is transmitted through the glass fiber thread, the light will also move along the surface because the fiber is thinner than wavelength of the light. This creates strong interaction between the light and the atoms sitting securely above the surface of the fiber.

“We have developed a method where we can measure the number of atoms. We send two laser beams with different frequencies through the glass fiber. If there were no atoms on the fiber, the speed of light would be the same for both light beams. However, the atoms affect the two frequencies differently and by measuring the difference in the speed of light for the two light beams on each side of the atoms’ absorption lines, you can measure the number of atoms along the fiber. We have shown that we can hold 2,500 atoms with an uncertainty of just eight atoms,” says Jürgen Appel.

These are fantastic results. Without this method, you would have to use resonant light (light that the atoms absorb) and then you would scatter photons, which would kick the atoms out of the trap, says Jürgen Appel and explains that with this new method they can measure and control the atoms so that only 14 percent are kicked out of the trap and are lost.

“Our resolution is only limited by the natural quantum noise (the laser light’s own minimal fluctuations) so our method could be used for so-called entangled states of atoms along the fiber. Such an entangled system with strongly interacting atoms and light is of great interest for future quantum computer networks,” notes Jürgen Appel.

News Release Source :  Atoms Queue up for Quantum Computer Networks

Tuesday, January 6, 2015

FQHE: Experimental Progress and Quantum Computing Applications

Fractional quantum Hall effect: Experimental progress and quantum computing applications

The Hall effect, discovered in 1879, is observable when a Hall voltage perpendicular to the current is produced across a conductor under a magnetic field. Although the Hall effect was discovered in a sheet of gold leaf by Edwin Hall, this effect does not require a two-dimensional condition.

[caption id="attachment_528" align="aligncenter" width="615"]Fractional quantum Hall effect: Experimental progress and quantum computing applications This shows the first experimental observation of 5/2 FQHE state.[/caption]

A century later, in 1980, the quantum Hall effect (QHE) was observed in two-dimensional electron gas (2DEG) system. The QHE occurs when a two-dimensional electron gas is exposed to a very low temperature and a very high magnetic field. The classical Hall resistance becomes quantized numbers in QHE. Usually, electrons are confined in a GaAs-AlGaAs interface potential well, formed by the two semiconductors with band offset.

The fractional quantum Hall effect (FQHE) was discovered in 1982. FQHE has almost the same characteristic as the QHE, with the Hall resistance quantized as h/e2 over a fraction. The first fraction observed is 1/3.

Many theoretical and experimental efforts continue in the field of the FQHE. Scientists at Peking University's International Center for Quantum Materials outline previous research and recent discoveries and technical developments in the field in a new paper , "Recent Experimental Progress of Fractional Quantum Hall Effect: 5/2 Filling State and Graphene," published in the Beijing-based journal National Science Review.

The 5/2 filling factor state is special for being an even denominator state, since most of the previously observed fractional quantum Hall states have odd denominator fractions. The observation of the 5/2 state demands new theoretical concepts. This even denominator fractional quantum Hall state can be viewed as a new testing ground to study complicated many-body physics involving simple electrons.

Their paper covers the progress of the 5/2 state in terms of energy gap, spin polarization study, fractional charge and statistics. The relationship between the energy gap and other experimental parameters, such as electron density, mobility, sample quality, are outlined.

The confusing results of spin polarization and the interference experiments are also reviewed. The Peking University scientists acknowledge in the paper that the "5/2 state needs extra efforts to determine its ground state wave function."

The paper's co-authors likewise survey recent progress in researching FQHE in monolayer graphene. Graphene has gained increasing scientific attention due to its peculiar band structure, corresponding two-dimensional massless Dirac-like excitations and great application potential. The quantum Hall effect in graphene has even been found at room temperature, which makes QHE-based applications more attractive and likely to become a focus of research in the future.

The FQHE has been observed in graphene since 2009. Typically this effect has been studied in semiconductors and graphene as a new platform for two-dimensional electrons. FQHE in graphene provides an interesting platform for experiments in many-body physics.


This research received funding from the National Basic Research Program of China (2012CB821402 and 2012CB921301) and the National Natural Science Foundation of China (91221302, 11274020 and 11322435).

See the article: Xi Lin, Ruirui Du, Xincheng Xie. "Recent Experimental Progress of Fractional Quantum Hall Effect: 5/2 Filling State and Graphene". National Science Review, (December 2014) 1 (4): 564?579

The National Science Review is the first comprehensive scholarly journal released in English in China that is aimed at linking the country's rapidly advancing community of scientists with the global frontiers of science and technology. The journal also aims to shine a worldwide spotlight on scientific research advances across China.

News Release Source : Fractional quantum Hall effect: Experimental progress and quantum computing applications