Quantum Physics  

Michael J. Biercuk is a physicist working to harness the strangest rules of quantum mechanics as a resource powering a new generation of quantum technologies. These technologies may even allow us to see into the future. 

The software platforms we use every day operate on hardware that takes decades of research to develop. But what if we could build that technology faster and smarter? Michael J. Biercuk is a technologist and physicist working at the forefront of quantum science, He believes that quantum computing may provide a profound transformative swing to that way that we build technology, atom by atom, electron by electron.

According to Biercuk, as remarkable as our present microprocessor technology is, it is still just the result of the processes that is still akin to machining the tooth of a gear out of brass. The precision of this top-down fabrication, while impressive is about to be blown away.

"We now stand at the precipice of a radical change in the way we build technology."

"We now stand at the precipice of a radical change in the way we build technology," stated Biercuk in a recent TEDx Talk in Sydney, Australia. "Instead of starting at the top, and working our way down, we're now looking to build technology from the bottom up, atom by atom, electron by electron."

Individual atom construction will be the building blocks of new technologies that are not only smaller and more compact, but behave according to the laws of quantum physics. In simplistic terms this means that materials will no longer be able to be considered as being made up of atomic billiard balls, but of waves.

"Now we are learning how we can control and harness these phenomena as resources powering a new generation of technologies, much the way we use the flow of electricity to power our technology today," he states.

He briefly explains how his experiments in quantum simulation using 300 atoms of beryllium, occupying less than a square millimeter can yield the equivalent computational power as a Turing machine that were constructed out of all the matter in the known universe.

Such technology is even pushing us farther into the realm of science fiction.

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In a recently published paper in the journal Nature Communications, Biercuk and his colleagues have demonstrated the ability to "see" the future of quantum systems, and used that knowledge to preempt their demise, in a major achievement that could help bring the strange and powerful world of quantum technology closer to reality.

The physicists have taken a technical quantum leap in addressing a major obstacle to building reliable quantum technologies—decoherence, or the randomisation of quantum systems by their environments— which effectively destroys the useful quantum character. The researchers used machine learning techniques to predict how quantum systems will change and then preventing the system's breakdown from occurring.

Biercuk is a quantum physicist and technologist at the University of Sydney, and a Chief Investigator in the Australian Research Council Centre of Excellence for Engineered Quantum Systems (EQuS). His own group – the Quantum Control Laboratory – is discovering how to power a new generation of advanced technologies using the strangest rules of quantum physics.

Biercuk highlighted the challenges of making predictions in a quantum world: "Humans routinely employ predictive techniques in our daily experience; for instance, when we play tennis we predict where the ball will end up based on observations of the airborne ball," he said.

"This works because the rules that govern how the ball will move, like gravity, are regular and known. But what if the rules changed randomly while the ball was on its way to you? In that case it's next to impossible to predict the future behavior of that ball.

"And yet this situation is exactly what we had to deal with because the disintegration of quantum systems is random. Moreover, in the quantum realm observation erases quantumness, so our team needed to be able to guess how and when the system would randomly break.

"We effectively needed to swing at the randomly moving tennis ball while blindfolded."

What might look like random behavior actually contained enough information for a computer program to guess how the system would change in the future. It could then predict the future without direct observation, which would otherwise erase the system's useful characteristics.

The predictions were remarkably accurate, allowing the team to use their guesses preemptively to compensate for the anticipated changes.

Doing this in real time allowed the team to prevent the disintegration of the quantum character, extending the useful lifetime of the qubits.

"We know that building real quantum technologies will require major advances in our ability to control and stabilise qubits - to make them useful in applications,"  Biercuk said.

"We're excited to be developing new capabilities that turn quantum systems from novelties into useful technologies. The quantum future is looking better all the time," Professor Biercuk said.

SOURCES  TEDx Talks, EurekAlert

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Quantum Physics  

Scientists have unraveled a new method of heat conduction that improves earlier attempts by ten thousand times. The invention could be a major step in the creation of super-cooled quantum computers.

Scientists at Aalto University, Finland, have succeeded in transporting heat maximally effectively ten thousand times further than ever before. The discovery may lead to a giant leap in the development of quantum computers.

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Heat conduction is a fundamental physical phenomenon utilized in clothing, housing, car industry, and electronics. The research group, led by quantum physicist Mikko Möttönen has now made one of these groundbreaking discoveries. This new invention revolutionizes quantum-limited heat conduction which means as efficient heat transport as possible from point A to point B.

"This work establishes the integration of normal-metal components into the framework of circuit quantum electrodynamics which provides a basis for the superconducting quantum computer," write the authors of the study, which was recently published in the journal, Nature Physics.

Quantum technology is still a developing research field, but its most promising application is the super-efficient quantum computer. In the future, it can solve problems that a normal computer would never be able to solve. The efficient operation of a quantum computer requires that it can be cooled down efficiently. At the same time, a quantum computer is prone to errors due to external noise.

Möttönen's invention could be applied to cooling quantum processors very efficiently and so cleverly that the operation of the computer is not disturbed.  To see the importance of cooling for quantum computers, consider the steps that D-Wave has to take with its machines.

"Our research started already in 2011 and advanced little by little. It feels really great to achieve a fundamental scientific discovery that has real practical applications", says Möttönen.

In the QCD Labs in Finland, Möttönen's research group succeeded in measuring quantum-limited heat transport over distances up to a meter. A meter doesn't sound very long at first, but previously scientists have been able to measure such heat transport only up to distances comparable to the thickness of a human hair.

"For computer processors, a meter is an extremely long distance. Nobody wants to build a larger processor than that", stresses Möttönen.

The team came up with the idea to use a transmission line with no electrical resistance to transport photons. A superconducting line was built on a silicon chip with the size of a square centimeter. Tiny resistors were placed at the ends of the transmission line. The research results were obtained by measuring induced changes in the temperatures of these resistors.

"For computer processors, a meter is an extremely long distance. Nobody wants to build a larger processor than that."

Although in previous experiments quantum-limited heat transport has been observed for lattice vibrations, or phonons, electrons, and electromagnetic fluctuations, the achieved distances have been very short compared to our macroscopic world. "We used microwave photons flying in a superconducting transmission line as the heat carriers. Photons are generally know to be good heat carriers over long distances," explains Möttönen.

The Quantum Computing and Devices (QCD) group led by Möttönen was able to show that quantum-limited heat conduction is possible over long distances. The result enables the application of this phenomenon outside laboratories. Essentially, the device built by the team fundamentally changes how heat conduction can be utilized in practice.

SOURCE  Phys Org

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Ideas  

Where does the beauty and complexity of life come from? Darwin's "natural selection" explains survival of the fittest, but doesn't explain why life gravitates towards beauty or complexity. Watch this video from Upriser to see where life's majesty may really be coming from, and how this knowledge could change the world... 42?

Some people recognize that the ultimate answer to life, the universe and everything is quite simply and elegantly the number 42, (that is, according to the writings of Douglas Adams), and that our entire existence on this planet is a pan-galactic effort to discover the actual question to make sense of that answer. In those terms, then, the video below from UPRISER's Garret John LoPorto is designed to further reveal the mysterious hyper-dimensional reality of life and how it affects the universe and everything.

SOURCE  Upriser This video is part of UPRISER's From the Future video series.

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Quantum Computers  

The promise of quantum computers has a big obstacle to overcome—the environments of the devices easily introduce error to the system. Now researchers have created a small quantum computing array that for the first time performs with a Sudoku-like error correction method that might pave the way toward practical devices. The team behind the breakthrough have also just joined Google, to further their research.

R
esearchers in the UC Santa Barbara’s physics professor John Martinis’ lab have developed quantum circuitry that self-checks for errors and suppresses them, preserving a qubits’ state(s) and imbuing the system with the highly sought-after reliability that may be the long sought after foundation for the building large-scale superconducting quantum computers.

Keeping qubits error-free, or stable enough to reproduce the same result time and time again, is one of the major hurdles scientists on the forefront of quantum computing face.

“One of the biggest challenges in quantum computing is that qubits are inherently faulty,” said Julian Kelly, graduate student researcher and co-lead author of a research paper that was published in the journal Nature. “So if you store some information in them, they’ll forget it.”

Unlike classical computing, in which the computer bits exist on one of two binary (“yes/no”, or “true/false”) positions, qubits can exist at any and all positions simultaneously, in various dimensions. It is this property, called “superpositioning,” that gives quantum computers their phenomenal computational power, but it is also this characteristic which makes qubits prone to “flipping,” especially when in unstable environments, and thus difficult to work with.

 “It’s hard to process information if it disappears,” said Kelly.

However, that obstacle may just have been cleared by Kelly, postdoctoral researcher Rami Barends, staff scientist Austin Fowler and others in the Martinis Group.

The error process involves creating a scheme in which several qubits work together to preserve the information, said Kelly. To do this, information is stored across several qubits.

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“And the idea is that we build this system of nine qubits, which can then look for errors,” he said. Qubits in the grid are responsible for safeguarding the information contained in their neighbors, he explained, in a repetitive error detection and correction system that can protect the appropriate information and store it longer than any individual qubit can.

“This is the first time a quantum device has been built that is capable of correcting its own errors,” said Fowler. For the kind of complex calculations the researchers envision for an actual quantum computer, something up to a hundred million qubits would be needed, but before that a robust self-check and error prevention system is necessary.

Key to this quantum error detection and correction system is a scheme developed by Fowler, called the surface code. It uses parity information — the measurement of change from the original data (if any) — as opposed to the duplication of the original information that is part of the process of error detection in classical computing. That way, the actual original information that is being preserved in the qubits remains unobserved as follows quantum physics.

"This is the first time a quantum device has been built that is capable of correcting its own errors."

“You can’t measure a quantum state, and expect it to still be quantum,” explained Barends. The very act of measurement locks the qubit into a single state and it then loses its superpositioning power, he said. Therefore, in something akin to a Sudoku puzzle, the parity values of data qubits in a qubit array are taken by adjacent measurement qubits, which essentially assess the information in the data qubits by measuring around them.

“So you pull out just enough information to detect errors, but not enough to peek under the hood and destroy the quantum-ness,” said Kelly.

This development represents a meeting of the best in the science behind the physical and the theoretical in quantum computing — the latest in qubit stabilization and advances in the algorithms behind the logic of quantum computing.

“It’s a major milestone,” said Barends. “Because it means that the ideas people have had for decades are actually doable in a real system.”

The Martinis Group continues to refine its research to develop this important new tool. This particular quantum error correction has been proved to protect against the “bit-flip” error, however the researchers have their eye on correcting the complimentary error called a “phase-flip,” as well as running the error correction cycles for longer periods to see what behaviors might emerge.

Martinis and the senior members of his research group have, since this research was performed, entered into a partnership with Google.

The recruitment of the Martinis group signals Google's intent to recruit or tap into talent with wide-ranging expertise at the Google Quantum Artificial Intelligence Lab which also involves NASA. The move also inaugurates a new era of cooperation between academic researchers and D-Wave (under the Google umbrella). The scenario would have seemed unbelievable just several years ago because of the skepticism and heated debates surrounding D-Wave's machines.

SOURCE  UCSB

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 Quantum Physics  

Quantum entanglement is weird enough, but it might get weirder still through a possible association with hypothetical wormholes. Over the past year, theorists have been hard at work exploring the entanglement of two black holes. New research advances the story by showing that a string-based representation of two entangled quarks is equivalent to the spacetime contortions of a wormhole.

Physicists at the University of Washington and Stony Brook University in New York have found that quantum entanglement, a perplexing phenomenon of quantum mechanics that Albert Einstein once referred to as spooky action at a distance, could be even spookier than Einstein perceived.

The researchers believe the phenomenon might be intrinsically linked with wormholes, hypothetical features of space-time that in popular science fiction can provide a much-faster-than-light shortcut from one part of the universe to another.

But here’s the catch: One couldn’t actually travel, or even communicate, through these wormholes, said Andreas Karch, a UW physics professor.

The work has been published in Physical Review Letters.

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Quantum entanglement occurs when a pair or a group of particles interact in ways that dictate that each particle’s behavior is relative to the behavior of the others. In a pair of entangled particles, if one particle is observed to have a specific spin, for example, the other particle observed at the same time will have the opposite spin.

The “spooky” part is that, as past research has confirmed, the relationship holds true no matter how far apart the particles are – across the room or across several galaxies. If the behavior of one particle changes, the behavior of both entangled particles changes simultaneously, no matter how far away they are.

Recent research indicated that the characteristics of a wormhole are the same as if two black holes were entangled, then pulled apart. Even if the black holes were on opposite sides of the universe, the wormhole would connect them.

Black holes, which can be as small as a single atom or many times larger than the sun, exist throughout the universe, but their gravitational pull is so strong that not even light can escape from them.

If two black holes were entangled, Karch said, a person outside the opening of one would not be able to see or communicate with someone just outside the opening of the other.

“The way you can communicate with each other is if you jump into your black hole, then the other person must jump into his black hole, and the interior world would be the same,” he said.

The work demonstrates an equivalence between quantum mechanics, which deals with physical phenomena at very tiny scales, and classical geometry – “two different mathematical machineries to go after the same physical process,” Karch said. The result is a tool scientists can use to develop broader understanding of entangled quantum systems.

“We’ve just followed well-established rules people have known for 15 years and asked ourselves, ‘What is the consequence of quantum entanglement?’”


SOURCE  University of Washington

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 Quantum Computing  

A normally fragile quantum state has been shown to survive at room temperature for a world record 39 minutes, overcoming a key barrier towards building ultrafast quantum computers.

An international team including Stephanie Simmons of Oxford University report in this week's Science a test performed as part of a project led by Mike Thewalt of Simon Fraser University, Canada, and colleagues. In conventional computers, data is stored as a string of 1s and 0s. In the experiment, quantum bits of information, 'qubits', were put into a 'superposition' state in which they can be both 1s and 0 at the same time – enabling them to perform multiple calculations simultaneously.

In the experiment, the team raised the temperature of a system, in which information is encoded in the nuclei of phosphorus atoms in silicon, from -269°C to 25°C and demonstrated that the superposition states survived at this balmy temperature for 39 minutes – outside of silicon the previous record for such a state's survival at room temperature was around two seconds. The team even found that they could manipulate the qubits as the temperature of the system rose, and that they were robust enough for this information to survive being 'refrozen' (the optical technique used to read the qubits only works at very low temperatures).

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'Thirty-nine minutes may not seem very long but as it only takes one-hundred-thousandth of a second to flip the nuclear spin of a phosphorus ion – the type of operation used to run quantum calculations – in theory over two million operations could be applied in the time it takes for the superposition to naturally decay by 1%. Having such robust, as well as long-lived, qubits could prove very helpful for anyone trying to build a quantum computer,' said Stephanie Simmons of Oxford University's Department of Materials, an author of the paper.

'This opens up the possibility of truly long-term coherent information storage at room temperature,' said Mike Thewalt, who performed the test at Simon Fraser University in Burnaby, British Columbia, Canada, with colleagues.

The team began with a sliver of silicon doped with small amounts of other elements, including phosphorus. Quantum information was encoded in the nuclei of the phosphorus atoms: each nucleus has an intrinsic quantum property called 'spin', which acts like a tiny bar magnet when placed in a magnetic field. Spins can be manipulated to point up (0), down (1), or any angle in between, representing a superposition of the two other states.

The team prepared their sample at just 4°C above absolute zero (-269°C) and placed it in a magnetic field. Additional magnetic field pulses were used to tilt the direction of the nuclear spin and create the superposition states. When the sample was held at this cryogenic temperature, the nuclear spins of about 37% of the ions – a typical benchmark to measure quantum coherence – remained in their superposition state for three hours. The same fraction survived for 39 minutes when the temperature of the system was raised to 25°C.

'These lifetimes are at least ten times longer than those measured in previous experiments,' said Stephanie Simmons. 'We've managed to identify a system that seems to have basically no noise. They're high-performance qubits.'

There is still some work ahead before the team can carry out large-scale quantum computations. The nuclear spins of the 10 billion or so phosphorus ions used in this experiment were all placed in the same quantum state. To run calculations, however, physicists will need to place different qubits in different states. 'To have them controllably talking to one another – that would address the last big remaining challenge,' said Simmons.

A report of the research, entitled 'Room-Temperature Quantum Bit Storage Exceeding 39 Minutes Using Ionized Donors in Silicon-28', is published in this week's Science.



SOURCE  University of Oxford

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 Physics  

Physicists have discovered the amplituhedron — a geometric object that dramatically simplifies calculations of particle interactions and does not require space and time as part of the inherent calculations.

Physicists have discovered the
amplituhedron — a geometric object that dramatically simplifies calculations of particle interactions and does not require space and time as part of the inherent calculations.

The amplituhedron makes quantum physics calculations much simpler than anything that has been done before, replacing hundreds of pages of Feynman diagrams in some cases.

The revelation that particle interactions, the most basic events in nature, may be consequences of geometry significantly advances a decades-long effort to reformulate quantum field theory, the body of laws describing elementary particles and their interactions.

“The degree of efficiency is mind-boggling,” said Jacob Bourjaily, a theoretical physicist at Harvard University and one of the researchers who developed the new idea. “You can easily do, on paper, computations that were infeasible even with a computer before.”

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The new geometric version of quantum field theory could also aid the search for a theory of quantum gravity that would seamlessly connect the large- and small-scale pictures of the universe. Attempts thus far to incorporate gravity into the laws of physics at the quantum scale have run up against nonsensical infinities and deep paradoxes. The amplituhedron, or a similar geometric object, could help by removing two deeply rooted principles of physics: locality and unitarity.

“Both are hard-wired in the usual way we think about things,” said Nima Arkani-Hamed, a professor of physics at the Institute for Advanced Study in Princeton, N.J., and the lead author of the new work, which he is presenting in talks (see below) and in a forthcoming paper. “Both are suspect.”

Locality is the notion that particles can interact only from adjoining positions in space and time. And unitarity holds that the probabilities of all possible outcomes of a quantum mechanical interaction must add up to one. The concepts are the central pillars of quantum field theory in its original form, but in certain situations involving gravity, both break down, suggesting neither is a fundamental aspect of nature.

In keeping with this idea, the new geometric approach to particle interactions removes locality and unitarity from its starting assumptions. The amplituhedron is not built out of space-time and probabilities; these properties merely arise as consequences of the jewel’s geometry. The usual picture of space and time, and particles moving around in them, is a construct.

“It’s a better formulation that makes you think about everything in a completely different way,” said David Skinner, a theoretical physicist at Cambridge University.

The amplituhedron itself does not describe gravity. But Arkani-Hamed and his collaborators think there might be a related geometric object that does. Its properties would make it clear why particles appear to exist, and why they appear to move in three dimensions of space and to change over time.

Because “we know that ultimately, we need to find a theory that doesn’t have” unitarity and locality, Bourjaily said, “it’s a starting point to ultimately describing a quantum theory of gravity.”

SOURCE  Simons Foundation

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 Artificial Intelligence  

University of Calgary physicist Barry Sanders and his research team employed artificial intelligence to devise a strategy that avoids limits of measurement imposed by the quantum world.

Is it possible to measure something very precisely – an atomic clock driven by oscillating electrons, for example – when we live in a quantum world of uncertainty?

University of Calgary physicist Barry Sanders and his research team employed artificial intelligence to devise a strategy that avoids limits of measurement imposed by the quantum world.

“The main ‘message’ in my work is that artificial intelligence methods work for quantum-related problems and work very well,” says Sanders, professor of Physics and Astronomy, iCORE Chair of Quantum Information Science, and director of the university’s Institute for Quantum Science and Technology.

He and his research team, which included post-doctoral researcher Neil Lovett and European undergraduate students Cécile Crosnier and Martí Perarnau-Llobet, published their new approach as the cover story in Physical Review Letters, a top-ranked physics journal.

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Quantum physics is a branch of science that deals with discrete, indivisible units of energy called “quanta” as described by the Quantum Theory.

We live in a quantum world. Or, as Sanders puts it: “The universe is quantum.”

His team’s new paper involves “metrology,” the science of measurement. More specifically, the work involves quantum metrology: making the best use of quantum properties to measure things as precisely as possible, and to surpass the quantum limit imposed by the “uncertainty principle.”

This principle says that in the quantum world, it is impossible to measure both the momentum and the position of a particle perfectly precisely. So there is a limit or an uncertainty to measurement.

To “beat the limit,” Sanders and his team used an approach called adaptive quantum metrology. The challenge is that this approach requires measurement, feedback and control sequences that are beyond human ability to devise.

http://orma.com/

The team turned to artificial intelligence for a solution. Using western Canada’s WestGrid supercomputer system, they ‘taught’ the machine how to use each measurement of a particle in order to measure the next particle, and to adapt this succession of measurements to be “infinitely precise.”

This “reinforcement learning” method is similar to how a computer learns to play chess, Sanders explains. “Each time it plays, it is effectively rewarded or punished, depending on whether it wins or loses. And it then gets better and better.”

The work may lead to ultra-precise atomic clocks, extremely accurate Global Positioning System instruments or a way to measure “gravitational waves” – ripples in the curvature of spacetime for which there’s indirect evidence but which have yet to be detected.

“This research will matter down the road,” Sanders says. “As usual in physics (the discovery of the laser, for example), the most important implications are unforeseeable.”


SOURCE  University of Calgary, Top Image WestGrid animation of Solar Wind

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Scientists at IBM Research have achieved major advances in quantum computing device performance that they say may accelerate the realization of a practical, full-scale quantum computer, with quantum states lasting up to 100 microseconds — a 2 to 4 times improvement over previous results. Thes major advances in device performance that may accelerate the realization of a practical, full-scale quantum computer. For specific applications, quantum computing, which exploits the underlying quantum mechanical behavior of matter, has the potential to deliver computational power that is unrivaled by any supercomputer today.

The scientists have established three new records for reducing errors in elementary computations and retaining the integrity of quantum mechanical properties in quantum bits (qubits) — the basic units that carry information within quantum computing.

IBM has employed superconducting qubits, which use established microfabrication techniques developed for silicon technology, providing the potential to one day scale up to and manufacture thousands or millions of qubits.

IBM researchers will be presenting their latest results at the annual American Physical Society meeting taking place February 27-March 2, 2012 in Boston.
The Possibilities of Quantum Computing

The special properties of qubits will allow quantum computers to work on millions of computations at once, while desktop PCs can typically handle minimal simultaneous computations. For example, a single 250-qubit state contains more bits of information than there are atoms in the universe.

These properties will have widespread implications foremost for the field of data encryption where quantum computers could factor very large numbers like those used to decode and encode sensitive information. Other potential applications for quantum computing may include searching databases of unstructured information, performing a range of optimization tasks and solving previously unsolvable mathematical problems.

Quantum states up to 100 microseconds

One of the great challenges for scientists seeking to harness the power of quantum computing is controlling or removing quantum decoherence — the creation of errors in calculations caused by interference from factors such as heat, electromagnetic radiation, and materials defects. To deal with this problem, scientists have been experimenting for years to discover ways of reducing the number of errors and of lengthening the time periods over which the qubits retain their quantum mechanical properties. When this time is sufficiently long, error correction schemes become effective making it possible to perform long and complex calculations.

IBM has recently been experimenting with a unique “three dimensional” superconducting qubit (3D qubit), an approach that was initiated at Yale University. Among the results, the IBM team has used a 3D qubit to extend the amount of time that the qubits retain their quantum states up to 100 microseconds — a 2 to 4 times improvement over previously reported records. This value reaches just past the minimum threshold to enable effective error correction schemes and suggests that scientists can begin to focus on broader engineering aspects for scalability.

In separate experiments, the group at IBM also demonstrated a more traditional “two-dimensional” qubit (2D qubit) device and implemented a two-qubit logic operation — a controlled-NOT (CNOT) operation, which is a fundamental building block of a larger quantum computing system. Their operation showed a 95 percent success rate, enabled in part due to the long coherence time of nearly 10 microseconds. These numbers are on the cusp of effective error correction schemes and greatly facilitate future multi-qubit experiments.

Quantum computing progress

“The superconducting qubit research led by the IBM team has been progressing in a very focused way on the road to a reliable, scalable quantum computer. The device performance that they have now reported brings them nearly to the tipping point; we can now see the building blocks that will be used to prove that error correction can be effective, and that reliable logical qubits can be realized,” observes David DiVincenzo, professor at the Institute of Quantum Information, Aachen University and Forschungszentrum Juelich.

Based on this progress, optimism about superconducting qubits and the possibilities for a future quantum computer are rapidly growing. While most of the work in the field to date has focused on improvements in device performance, efforts in the community now must now include systems integration aspects, such as assessing the classical information processing demands for error correction, I/O issues, feasibility, and costs with scaling.

IBM envisions a practical quantum computing system as including a classical system intimately connected to the quantum computing hardware. Expertise in communications and packaging technology will be essential at and beyond the level presently practiced in the development of today’s most sophisticated digital computers.

IBM Press Release