One Quantum Step for Man, One Giant Leap for Computing... Vol 8 rel 1

Quantum computing is computing using quantum-mechanical phenomena, such as superposition and entanglement. What? Yes, not everyone has taken the Physics 101 class concerning quantum entanglements. Hence, we thought as this quantum computing age has begun to introduce itself to our lives (not mentioning the "Mandela effect") in addressing the world's impenetrable computing challenges, we wanted to introduce the concepts in the digestible ways.

How powerful are quantum computers?

At 100 qubits a single quantum computer processor would, theoretically, be more powerful than all the supercomputers on the planet combined. ... Quantum computers are spooky devices that don't follow the normal rules of physics. Instead of bits, like classical computers, they use qubits.

Why would quantum computers be important?

Quantum computing takes advantage of the strange ability of subatomic particles to exist in more than one state at any time. Due to the way the tiniest of particles behave, operations can be done much more quickly and use less energy than classical computers. ... Quantum computing uses quantum bits, or 'qubits' instead.

What is a qubit made of?

Until now, most silicon-based qubits have been made from the electron or the nucleus of a single phosphorus atom. However, Andrea Morello at the University of New South Wales in Australia and his colleagues have a design for a qubit – the smallest unit of quantum information – that could help get round some of the difficulties of manufacturing quantum computers at an atomic scale.

At the moment, making quantum systems using silicon is difficult because the qubits have to be very close to each other, about 10 to 20 nanometres apart, in order to communicate. This leaves little room to place the electronics needed to make a quantum computer work.

But by combining an electron and nucleus into one qubit, Morello and his team think they’ve found a way to let qubits communicate over distances of up to 500 nanometres. “This would allow you to cram other things between qubits,” says Morello.

The team’s design uses both the nucleus and the electron of a phosphorus atom to create a single qubit inside a layer of silicon.

Qubits in silicon systems interact through electric fields, and Morello’s team shows that it’s possible to extend the reach of those electric fields by pulling the electron further away from the nucleus of each atom.

This overcomes a couple of the major hurdles that held back silicon-based quantum systems, says Simon Devitt at Macquarie University in Sydney, and could eventually make it possible to create quantum computers with millions of qubits that can simulate simple chemical reactions.

Silicon-based qubits aren’t the only candidates for quantum computers. Google is making superconductor-based quantum chips, and claims it is on track to build the first quantum computer capable of surpassing some of the abilities of ordinary computers later this year.

Open race

“Silicon is a bit further behind the pack,” says Devitt. But since the computer industry is already used to building chips out of silicon, silicon is well-placed to catch up or even surpass the performance of other quantum systems. Quantum computers made using silicon qubits might be less-error prone than other systems when it comes to building computers with thousands or millions of qubits, says Devitt.

However, silicon and superconducting quantum systems both only work in temperatures that are close to absolute zero, says Michele Reilly at Turing, a quantum start-up in California. She says diamond-based systems could be easier to scale-up because they use similar types of qubits to the silicon systems, but don’t need to be cooled to such extreme temperatures.

“The path is pretty open,” says Barbara Terhal at RWTH Aachen University in Germany. She says it’s still too early to know which system will end up powering the quantum computers of the future.

We’ll have to wait and see whether this new way of defining a qubit really does unleash the potential of silicon-based quantum computers, says Devitt. “This could be a potential solution that is kind of staring us in the face,” he says. “But they’re going to have to go into the lab and make this work.”

Does Moore's Law apply quantum computing?

Applying Moore's Law to Quantum Qubits. In 1965, Gordon Moore predicted that the number of transistors on a silicon chip would double every year. ... So the question comes up whether Moore’s Law can also be applied to quantum qubits. And early evidence suggests that indeed it may. If we take this as an assumption we can make rough forecasts for qubit capacities in the coming years and show when a quantum computer can be used to solve certain meaningful problems. The resulting graph is shown below:

How much does a quantum computer cost?

Quantum computers are indeed currently out of the price range of the average consumer, and will likely stay that way for a few years at least. The $15 million price tag for the D-Wave 2000Q has a long way to drop before it makes it to a Black Friday sale.Jul 31, 2017

How will quantum computers work?

The Turing machine, developed by Alan Turing in the 1930s, is a theoretical device that consists of tape of unlimited length that is divided into little squares. Each square can either hold a symbol (1 or 0) or be left blank. A read-write device reads these symbols and blanks, which gives the machine its instructions to perform a certain program. Does this sound familiar? Well, in a quantum Turing machine, the difference is that the tape exists in a quantum state, as does the read-write head. This means that the symbols on the tape can be either 0 or 1 or a superposition of 0 and 1; in other words the symbols are both 0 and 1 (and all points in between) at the same time. While a normal Turing machine can only perform one calculation at a time, a quantum Turing machine can perform many calculations at once.

Today's computers, like a Turing machine, work by manipulating bits that exist in one of two states: a 0 or a 1. Quantum computers aren't limited to two states; they encode information as quantum bits, or qubits, which can exist in superposition. Qubits represent atoms, ions, photons or electrons and their respective control devices that are working together to act as computer memory and a processor. Because a quantum computer can contain these multiple states simultaneously, it has the potential to be millions of times more powerful than today's most powerful supercomputers.　

You might object that something like superposition could perhaps be achieved using only ordinary classical physics — perhaps by processing two ordinary bits at the same time or something like that — in which case quantum computing wouldn't be that much more amazing than classical computing. But there is more to quantum physics than just superposition. If you look at a system of more than one qubit, then the individual components aren't generally independent of each other. Instead, they can be entangled. When you measure one of the qubits in an entangled system of two qubits, for example, then the outcome — whether you see a 0 or a 1 — immediately tells you what you will see when you measure the other qubit. Particles can be entangled even if they are separated in space, a fact that caused Einstein to call entanglement "spooky action at a distance".

Entanglement means that describing a system of several qubits using ordinary classical information, such as bits or numbers, isn't simply about stringing together the descriptions of the individual qubits. Instead, you need to describe all the correlations between the different qubits. As you increase the number of qubits, the number of those correlations grows exponentially: for n qubits there are 2ncorrelations. This number quickly explodes: to describe a system of 300 qubits you'd already need more numbers than there are atoms in the visible Universe. The idea is that, since you can't hope to write down the information contained in system of just a few hundred qubits using classical bits, perhaps a computer running on qubits, rather than classical bits, can perform tasks a classical computer can never hope to achieve. This is the real reason why physicists think quantum computing holds such promise.

There's a hitch however. While a quantum algorithm can take entangled qubits in superposition as input, the output will also usually be a quantum state — and such a state will generally change as soon as you try to observe it. "Nature pulls a trick here," says Jozsa. "She updates a quantum state, but then she doesn't allow you to get all the information." The art of quantum computing is to find ways of gaining as much information as possible from the unobservable.

What could a quantum computer do?

Jeremy O’Brien, physicist and professorial research fellow at the University of Bristol: “In less than 10 years quantum computers will begin to outperform everyday computers, leading to breakthroughs in artificial intelligence, the discovery of new pharmaceuticals and beyond. The very fast computing power given by quantum computers has the potential to disrupt traditional businesses and challenge our cyber security.”

Will quantum computers replace?

Quantum Computers Are Imminent But Will Not Replace Classical Computers. Initially, quantum computers were associated with cryptography, Modelling, mathematical challenges. Quantum computers have now moving beyond theoretical possibility and are entering commercial space. However they remain bulky and expensive. The reason is that most common methods e.g. using superconducting circuits, quantum annealing etc. need help of cryogenics to function. This also has energy implications in terms of maintaining such low temperatures. Hence they contain large cylindrical freezers, wires etc. while processor is a relatively small part of it. Secondly, initially the tasks where quantum computers prevail will be contrived problems set up to be difficult for a classical computer but easy for a quantum one. Besides, quantum computers still use classical sequencing and classical control of the operations. There are lots of areas where quantum algorithms that show any improvement over classical areas do not exist. In particular the end user experience for an average user will not change.

The next decade will see quantum leap in commercial use of quantum computers but the classical computers will continue to remain the dominant form of computing machines. And average end users will continue to identify computing power with the latter.

How hot do quantum computers get?

Quantum computing requires extremely cold temperatures, as sub-atomic particles must be as close as possible to a stationary state to be measured. The cores of D-Wave quantum computers operate at -460 degrees f, or -273 degrees c, which is 0.02 degrees away from absolute zero.

So “Once more unto the breach, dear friends, once more;”

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About Rick Ricker

An IT professional with over 23 years experience in Information Security, wireless broadband, network and Infrastructure design, development, and support.
For more information, contact Rick at (800) 399-6085 x502

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Source(s)

• https://plus.maths.org/content/how-does-quantum-commuting-work
• https://computer.howstuffworks.com/quantum-computer1.htm
• http://www.businessworld.in/article/Quantum-Computers-Are-Imminent-But-Will-Not-Replace-Classical-Computers/26-11-2017-132515/
• https://www.wired.co.uk/article/quantum-computing-explained
• https://www.newscientist.com/article/2146503-this-qubit-redesign-may-make-it-easier-to-make-quantum-computers/
• https://quantumcomputingreport.com/our-take/applying-moores-law-to-quantum-qubits/

____________________________________________________________
About Rick Ricker

An IT professional with over 23 years experience in Information Security, wireless broadband, network and Infrastructure design, development, and support.

For more information, contact Rick at (800) 399-6085 x502