Mediaboss Marketing

Doing calculations with a quantum computer is a race against time, thanks to the fragility of the quantum states at their heart. And new research suggests we may soon hit a wall in how long we can hold them together thanks to interference from natural background radiation.

While quantum computing could one day enable us to carry out calculations beyond even the most powerful supercomputer imaginable, were still a long way from that point. And a big reason for that is a phenomenon known as decoherence.

The superpowers of quantum computers rely on holding the qubitsquantum bitsthat make them up in exotic quantum states like superposition and entanglement. Decoherence is the process by which interference from the environment causes them to gradually lose their quantum behavior and any information that was encoded in them.

It can be caused by heat, vibrations, magnetic fluctuations, or any host of environmental factors that are hard to control. Currently we can keep superconducting qubits (the technology favored by the fields leaders like Google and IBM) stable for up to 200 microseconds in the best devices, which is still far too short to do any truly meaningful computations.

But new research from scientists at Massachusetts Institute of Technology (MIT) and Pacific Northwest National Laboratory (PNNL), published last week in Nature, suggests we may struggle to get much further. They found that background radiation from cosmic rays and more prosaic sources like trace elements in concrete walls is enough to put a hard four-millisecond limit on the coherence time of superconducting qubits.

These decoherence mechanisms are like an onion, and weve been peeling back the layers for the past 20 years, but theres another layer that left unabated is going to limit us in a couple years, which is environmental radiation, William Oliver from MIT said in a press release. This is an exciting result, because it motivates us to think of other ways to design qubits to get around this problem.

Superconducting qubits rely on pairs of electrons flowing through a resistance-free circuit. But radiation can knock these pairs out of alignment, causing them to split apart, which is what eventually results in the qubit decohering.

To determine how significant of an impact background levels of radiation could have on qubits, the researchers first tried to work out the relationship between coherence times and radiation levels. They exposed qubits to irradiated copper whose emissions dropped over time in a predictable way, which showed them that coherence times rose as radiation levels fell up to a maximum of four milliseconds, after which background effects kicked in.

To check if this coherence time was really caused by the natural radiation, they built a giant shield out of lead brick that could block background radiation to see what happened when the qubits were isolated. The experiments clearly showed that blocking the background emissions could boost coherence times further.

At the minute, a host of other problems like material impurities and electronic disturbances cause qubits to decohere before these effects kick in, but given the rate at which the technology has been improving, we may hit this new wall in just a few years.

Without mitigation, radiation will limit the coherence time of superconducting qubits to a few milliseconds, which is insufficient for practical quantum computing, Brent VanDevender from PNNL said in a press release.

Potential solutions to the problem include building radiation shielding around quantum computers or locating them underground, where cosmic rays arent able to penetrate so easily. But if you need a few tons of lead or a large cavern in order to install a quantum computer, thats going to make it considerably harder to roll them out widely.

Its important to remember, though, that this problem has only been observed in superconducting qubits so far. In July, researchers showed they could get a spin-orbit qubit implemented in silicon to last for about 10 milliseconds, while trapped ion qubits can stay stable for as long as 10 minutes. And MITs Oliver says theres still plenty of room for building more robust superconducting qubits.

We can think about designing qubits in a way that makes them rad-hard, he said. So its definitely not game-over, its just the next layer of the onion we need to address.

Image Credit: Shutterstock

See the rest here:
Could Quantum Computing Progress Be Halted by Background Radiation? - Singularity Hub

Sept. 1, 2020 A well-known quantum algorithm that is useful in studying and solving problems in quantum physics can be applied to problems in classical physics, according to a new study in the journal Physical Review Afrom University of WisconsinMadison assistant professor of physicsJeff Parker.

Quantum algorithms a set of calculations that are run on a quantum computer as opposed to a classical computer used for solving problems in physics have mainly focused on questions in quantum physics. The new applications include a range of problems common to physics and engineering, and expands on the types of questions that can be asked in those fields.

The reason we like quantum computers is that we think there are quantum algorithms that can solve certain kinds of problems very efficiently in ways that classical computers cannot, Parker says. This paper presents a new idea for a type of problem that has not been addressed directly in the literature before, but it can be solved efficiently using these same quantum computer types of algorithms.

The type of problem Parker was investigating is known as generalized eigenvalue problems, which broadly describe trying to find the fundamental frequencies or modes of a system. Solving them is crucial to understanding common physics and engineering questions, such as the stability of a bridges design or, more in line with Parkers research interests, the stability and efficiency of nuclear fusion reactors.

As the system being studied becomes more and more complex more components moving throughout three-dimensional space so does the numerical matrix that describes the problem. A simple eigenvalue problem can be solved with a pencil and paper, but researchers have developed computer algorithms to tackle increasingly complex ones. With the supercomputers available today, more and more difficult physics problems are finding solutions.

If you want to solve a three-dimensional problem, it can be very complex, with a very complicated geometry, Parker says. You can do a lot on todays supercomputers, but there tends to be a limit. Quantum algorithms may be able to break that limit.

The specific quantum algorithm that Parker studied in this paper, known as quantum phase estimation, had been previously applied to so-called standard eigenvalue problems. However, no one had shown that they could be applied to the generalized eigenvalue problems that are also common in physics. Generalized eigenvalue problems introduce a second matrix that ups the mathematical complexity.

Parker took the quantum algorithm and extended it to generalized eigenvalue problems. He then looked to see what types of matrices could be used in this problem. If the matrix is sparse meaning, if most of the numerical components that make it up are zero it means this problem could be solved efficiently on a quantum computer.

What I showed is that there are certain types of generalized eigenvalue problems that do lead to a sparse matrix and therefore could be efficiently solved on a quantum computer, Parker says. This type includes the very natural problems that often occur in physics and engineering, so this study provides motivation for applying these quantum algorithms more to generalized eigenvalue problems, because it hasnt been a big focus so far.

Parker emphasizes that quantum computers are in their infancy, and these classical physics problems are still best approached through classical computer algorithms.

This study provides a step in showing that the application of a quantum algorithm to classical physics problems can be useful in the future, and the main advance here is it shows very clearly another type of problem to which quantum algorithms can be applied, Parker says.

The study was completed in collaboration with Ilon Joseph at Lawrence Livermore National Laboratory. Funding support was provided by the U.S. Department of Energy to Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344 and U.S. DOE Office of Fusion Energy Sciences Quantum Leap for Fusion Energy Sciences (FWP SCW1680).

For additional images, visit https://www.physics.wisc.edu/2020/08/25/new-study-expands-types-of-physics-engineering-problems-that-can-be-solved-by-quantum-computers/

Source: University of WisconsinMadison

Continue reading here:
Study Expands Types of Physics, Engineering Problems That Can Be Solved by Quantum Computers - HPCwire

A

ndersen Cheng has a way with striking and memorable analogies. Boris Johnsons government is committing 1bn to building a Frankensteins monster, he says. Im trying to build a cage without any government funding to stop it running wild. The monster in question is the quantum computer, which is a hackers dream. The cage is what Post-Quantum was set up last year to create.

Cheng was born in Hong Kong but came to England to do his O-levels and A-levels. His parents sent him to a school in Devon. They wanted me to be as far from London as possible, he says. He duly learned to drive a tractor and milk cows, but went on to study engineering at Imperial College and do an MBA. When he started working in the City at the end of the Eighties as a computer auditor, there were only six portable compact computers in the whole company and disdain for the techies from people still using calculators.

Cheng became head of credit risk at JP Morgan in the midst of the dotcom bubble. He recalls how Boo.com burnt through $150m in 18 months. There just wasnt enough broadband speed for all those virtual mannequins spinning around, he says. After a spell in private equity, Cheng decided to break away and set up on his own as a consultant in the fast-growing realm of cryptography, working on top secret projects for the British government. It was so classified even the project name was secret, he says.

See the original post:
How Andersen Cheng plans to defend against the quantum computer - The Independent

It might all sound like a sci-fi concept, but building quantum networks is a key ambition for many countries around the world. Recently the US Department of Defense (DoE) published the first blueprint of its kind, laying out a step-by-step strategy to make the quantum internet dream come true, at least in a very preliminary form, over the next few years.

The US joined the EU and China in showing a keen interest in the concept of quantum communications. But what is the quantum internet exactly, how does it work, and what are the wonders that it can accomplish?

WHAT IS THE QUANTUM INTERNET?

The quantum internet is a network that will let quantum devices exchange some information within an environment that harnesses the weird laws of quantum mechanics. In theory, this would lend the quantum internet unprecedented capabilities that are impossible to carry out with today's web applications.

SEE: Managing AI and ML in the enterprise 2020: Tech leaders increase project development and implementation (TechRepublic Premium)

In the quantum world, data can be encoded in the state of qubits, which can be created in quantum devices like a quantum computer or a quantum processor. And the quantum internet, in simple terms, will involve sending qubits across a network of multiple quantum devices that are physically separated. Crucially, all of this would happen thanks to the whacky properties that are unique to quantum states.

That might sound similar to the standard internet. But sending qubits around through a quantum channel, rather than a classical one, effectively means leveraging the behavior of particles when taken at their smallest scale so-called "quantum states", which have caused delight and dismay among scientists for decades.

And the laws of quantum physics, which underpin the way information will be transmitted in the quantum internet, are nothing short of unfamiliar. In fact, they are strange, counter-intuitive, and at times even seemingly supernatural.

And so to understand how the quantum ecosystem of the internet 2.0 works, you might want to forget everything you know about classical computing. Because not much of the quantum internet will remind you of your favorite web browser.

WHAT TYPE OF INFORMATION CAN WE EXCHANGE WITH QUANTUM?

In short, not much that most users are accustomed to. At least for the next few decades, therefore, you shouldn't expect to one day be able to jump onto quantum Zoom meetings.

Central to quantum communication is the fact that qubits, which harness the fundamental laws of quantum mechanics, behave very differently to classical bits.

As it encodes data, a classical bit can effectively only be one of two states. Just like a light switch has to be either on or off, and just like a cat has to be either dead or alive, so does a bit have to be either 0 or 1.

Not so much with qubits. Instead, qubits are superposed: they can be 0 and 1 simultaneously, in a special quantum state that doesn't exist in the classical world. It's a little bit as if you could be both on the left-hand side and the right-hand side of your sofa, in the same moment.

The paradox is that the mere act of measuring a qubit means that it is assigned a state. A measured qubit automatically falls from its dual state, and is relegated to 0 or 1, just like a classical bit.

The whole phenomenon is called superposition, and lies at the core of quantum mechanics.

Unsurprisingly, qubits cannot be used to send the kind of data we are familiar with, like emails and WhatsApp messages. But the strange behavior of qubits is opening up huge opportunities in other, more niche applications.

QUANTUM (SAFER) COMMUNICATIONS

One of the most exciting avenues that researchers, armed with qubits, are exploring, is security.

When it comes to classical communications, most data is secured by distributing a shared key to the sender and receiver, and then using this common key to encrypt the message. The receiver can then use their key to decode the data at their end.

The security of most classical communication today is based on an algorithm for creating keys that is difficult for hackers to break, but not impossible. That's why researchers are looking at making this communication process "quantum". The concept is at the core of an emerging field of cybersecurity called quantum key distribution (QKD).

QKD works by having one of the two parties encrypt a piece of classical data by encoding the cryptography key onto qubits. The sender then transmits those qubits to the other person, who measures the qubits in order to obtain the key values.

SEE: The UK is building its first commercial quantum computer

Measuring causes the state of the qubit to collapse; but it is the value that is read out during the measurement process that is important. The qubit, in a way, is only there to transport the key value.

More importantly, QKD means that it is easy to find out whether a third party has eavesdropped on the qubits during the transmission, since the intruder would have caused the key to collapse simply by looking at it.

If a hacker looked at the qubits at any point while they were being sent, this would automatically change the state of the qubits. A spy would inevitably leave behind a sign of eavesdropping which is why cryptographers maintain that QKD is "provably" secure.

SO, WHY A QUANTUM INTERNET?

QKD technology is in its very early stages. The "usual" way to create QKD at the moment consists of sending qubits in a one-directional way to the receiver, through optic-fibre cables; but those significantly limit the effectiveness of the protocol.

Qubits can easily get lost or scattered in a fibre-optic cable, which means that quantum signals are very much error-prone, and struggle to travel long distances. Current experiments, in fact, are limited to a range of hundreds of kilometers.

There is another solution, and it is the one that underpins the quantum internet: to leverage another property of quantum, called entanglement, to communicate between two devices.

When two qubits interact and become entangled, they share particular properties that depend on each other. While the qubits are in an entangled state, any change to one particle in the pair will result in changes to the other, even if they are physically separated.The state of the first qubit, therefore, can be "read" by looking at the behavior of its entangled counterpart. That's right: even Albert Einstein called the whole thing "spooky action at a distance".

And in the context of quantum communication, entanglement could in effect, teleport some information from one qubit to its entangled other half, without the need for a physical channel bridging the two during the transmission.

HOW DOES ENTANGLEMENT WORK?

The very concept of teleportation entails, by definition, the lack of a physical network bridging between communicating devices. But it remains that entanglement needs to be created in the first place, and then maintained.

To carry out QKD using entanglement, it is necessary to build the appropriate infrastructure to first create pairs of entangled qubits, and then distribute them between a sender and a receiver. This creates the "teleportation" channel over which cryptography keys can be exchanged.

Specifically, once the entangled qubits have been generated, you have to send one half of the pair to the receiver of the key. An entangled qubit can travel through networks of optical fibre, for example; but those are unable to maintain entanglement after about 60 miles.

Qubits can also be kept entangled over large distances via satellite, but covering the planet with outer-space quantum devices is expensive.

There are still huge engineering challenges, therefore, to building large-scale "teleportation networks" that could effectively link up qubits across the world. Once the entanglement network is in place, the magic can start: linked qubits won't need to run through any form of physical infrastructure anymore to deliver their message.

During transmission, therefore, the quantum key would virtually be invisible to third parties, impossible to intercept, and reliably "teleported" from one endpoint to the next. The idea will resonate well with industries that deal with sensitive data, such as banking, health services or aircraft communications. And it is likely that governments sitting on top secret information will also be early adopters of the technology.

WHAT ELSE COULD WE DO WITH THE QUANTUM INTERNET?

'Why bother with entanglement?' you may ask. After all, researchers could simply find ways to improve the "usual" form of QKD. Quantum repeaters, for example, could go a long way in increasing communication distance in fibre-optic cables, without having to go so far as to entangle qubits.

That is without accounting for the immense potential that entanglement could have for other applications. QKD is the most frequently discussed example of what the quantum internet could achieve, because it is the most accessible application of the technology. But security is far from being the only field that is causing excitement among researchers.

The entanglement network used for QKD could also be used, for example, to provide a reliable way to build up quantum clusters made of entangled qubits located in different quantum devices.

Researchers won't need a particularly powerful piece of quantum hardware to connect to the quantum internet in fact, even a single-qubit processor could do the job. But by linking together quantum devices that, as they stand, have limited capabilities, scientists expect that they could create a quantum supercomputer to surpass them all.

SEE: Guide to Becoming a Digital Transformation Champion (TechRepublic Premium)

By connecting many smaller quantum devices together, therefore, the quantum internet could start solving the problems that are currently impossible to achieve in a single quantum computer. This includes expediting the exchange of vast amounts of data, and carrying out large-scale sensing experiments in astronomy, materials discovery and life sciences.

For this reason, scientists are convinced that we could reap the benefits of the quantum internet before tech giants such as Google and IBM even achieve quantum supremacy the moment when a single quantum computer will solve a problem that is intractable for a classical computer.

Google and IBM's most advanced quantum computers currently sit around 50 qubits, which, on its own, is much less than is needed to carry out the phenomenal calculations needed to solve the problems that quantum research hopes to address.

On the other hand, linking such devices together via quantum entanglement could result in clusters worth several thousands of qubits. For many scientists, creating such computing strength is in fact the ultimate goal of the quantum internet project.

WHAT COULDN'T WE DO WITH THE QUANTUM INTERNET?

For the foreseeable future, the quantum internet could not be used to exchange data in the way that we currently do on our laptops.

Imagining a generalized, mainstream quantum internet would require anticipating a few decades (or more) of technological advancements. As much as scientists dream of the future of the quantum internet, therefore, it is impossible to draw parallels between the project as it currently stands, and the way we browse the web every day.

A lot of quantum communication research today is dedicated to finding out how to best encode, compress and transmit information thanks to quantum states. Quantum states, of course, are known for their extraordinary densities, and scientists are confident that one node could teleport a great deal of data.

But the type of information that scientists are looking at sending over the quantum internet has little to do with opening up an inbox and scrolling through emails. And in fact, replacing the classical internet is not what the technology has set out to do.

Rather, researchers are hoping that the quantum internet will sit next to the classical internet, and would be used for more specialized applications. The quantum internet will perform tasks that can be done faster on a quantum computer than on classical computers, or which are too difficult to perform even on the best supercomputers that exist today.

SO, WHAT ARE WE WAITING FOR?

Scientists already know how to create entanglement between qubits, and they have even been successfully leveraging entanglement for QKD.

China, a long-time investor in quantum networks, has broken records on satellite-induced entanglement. Chinese scientists recently established entanglement and achieved QKD over a record-breaking 745 miles.

The next stage, however, is scaling up the infrastructure. All experiments so far have only connected two end-points. Now that point-to-point communication has been achieved, scientists are working on creating a network in which multiple senders and multiple receivers could exchange over the quantum internet on a global scale.

The idea, essentially, is to find the best ways to churn out lots of entangled qubits on demand, over long distances, and between many different points at the same time. This is much easier said than done: for example, maintaining the entanglement between a device in China and one in the US would probably require an intermediate node, on top of new routing protocols.

And countries are opting for different technologies when it comes to establishing entanglement in the first place. While China is picking satellite technology, optical fibre is the method favored by the US DoE, which is now trying to create a network of quantum repeaters that can augment the distance that separates entangled qubits.

In the US, particles have remained entangled through optical fibre over a 52-mile "quantum loop" in the suburbs of Chicago, without the need for quantum repeaters. The network will soon be connected to one of the DoE's laboratories to establish an 80-mile quantum testbed.

In the EU, the Quantum Internet Alliance was formed in 2018 to develop a strategy for a quantum internet, and demonstrated entanglement over 31 miles last year.

For quantum researchers, the goal is to scale the networks up to a national level first, and one day even internationally. The vast majority of scientists agree that this is unlikely to happen before a couple of decades. The quantum internet is without doubt a very long-term project, with many technical obstacles still standing in the way. But the unexpected outcomes that the technology will inevitably bring about on the way will make for an invaluable scientific journey, complete with a plethora of outlandish quantum applications that, for now, cannot even be predicted.

See more here:
What is the quantum internet? Everything you need to know about the weird future of quantum networks - ZDNet

The UK government has announced that it is backing the nation's first commercially available quantum computer to the tune of millions of pounds.

Quantum technology is estimated to offer 4 billion of economic opportunities globally by 2024 (and 341 billion through productivity gains in coming decades) - which will result in creation of new jobs, knowledge and skills in the United Kingdom, the government claims.

A Rigetti superconducting quantum computer is already commercially available in the Amazon Web Service (AWS) Bracket cloud, alongside other US-based systems using different approaches from D-Wave and IonQ. "This a key part of our plan to build back better using the latest technology, attract the brightest and best talent to the United Kingdom and encourage world-leading companies to invest here".

Pharmaceuticals, aerospace and transport are thought to be among the industries that will get maximum benefits from quantum computers. A recent BCG report projected the global quantum industry to reach 4B by 2024.

The University of Edinburgh will develop new techniques to test the hardware and the performance of the programmes that will run on the computer. Phasecraft will develop algorithms for energy, materials design and pharmaceutical purposes, while Standard Chartered Bank will look at financial applications.

It still sounds like early days in the development of a UK-based quantum computer - yesterday's investment kicked-off a three year development program.

"Oxford Instruments" new Proteox dilution refrigerator will be used as the cryogenic platform. "I am sure this collaboration will open a new future for many more innovative applications, and these applications will require an ecosystem where skills development, design & engineering excellence, and technology partners all combine to enable new discoveries and solutions', Simon added".

"We are excited to deliver the UK's first quantum computer and help accelerate the development of practical algorithms and applications", affirmed Rigetti Computing CEO Chad Rigetti. By providing access to quantum hardware, the collaboration aims to unlock new capabilities within the thriving United Kingdom ecosystem of quantum information science researchers, start-ups, and enterprises who have already begun to explore the potential impact of quantum computing.

The funding for the project forms part of the government's Quantum Technologies Challenge, which itself is led by the UK Research and Innovation public body, according to the press release.

Oxford Instruments plc published this content on 02 September 2020 and is exclusively responsible for the information contained therein. And more research should bring us closer to advanced quantum technologies and the grandest goal of quantum information science, creating a fault-tolerant quantum computer that can indefinitely compute without errors. The company's contributions range from underpinning mathematics through to developing software on real or emulated quantum hardware. It is hoped the quantum computer will provide better or quicker ways to solve problems in complex United Kingdom industries like pharmaceuticals, aerospace, and transport.

With over 100 academics, 120 research staff and over 1,600 students from over 80 countries worldwide the University of Edinburgh's School of Informatics is the largest European centre of its kind. It will also provide access to quantum computers for both research institutions and businesses.It is based at the Harwell Science and Innovation Campus in Oxfordshire. Standard Chartered's Data Science & Innovation group, with a proven research track record in quantum computing and machine learning/AI, has been active in quantum computing since 2017.

Read the original post:
Quantum computer to be hosted in Abingdon - ClickLancashire