# Quantum Computing: Recent Breakthroughs

Quantum computing has become quite a hot topic of late, with Canadian Prime Minister Justin Trudeau supposedly ‘schooling’ a snarky reporter who had broached the subject, or more recently, Australian Prime Minister Malcolm Turnbull, who addressed a 100-strong crowd of academics on the same during the opening of a new quantum computing lab complex at the University of New South Wales.

According to Professor O’Brien, Director of the Centre for Quantum Photonics at the University of Bristol and Visiting Fellow at Stanford University, quantum computing has the potential to revolutionize our lives, society and the economy on a whole, with a working system anticipated to be developed by 2020.

‘In less than ten 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. Businesses need to be ready for a quantum future because it’s coming,’ said O’Brien in January 2016.

The European Union has already announced funding worth EUR 1 billion (USD1.13 billion) to boost research and development efforts towards quantum computing, with the aim to turn scientific discoveries into practical applications.

**What is Quantum Computing?**

What is Quantum Computing, after all? Though it may sound like a term all grand and complex, quoted only by super-smart people and physicists, it is really a very interesting field that will possibly define our future. There are many tutorials and guides on the internet that can give you a pretty solid idea of what Quantum Computing is all about. Some good ones are by Science Alert, Explain That Stuff and The Guardian. The lecture below on Quantum Algorithms is particularly riveting and is a must-watch for all enthusiasts:

Following is an excerpt from a quantum computing course taught at the University of Amsterdam, which lucidly explains how quantum computation works:

‘Today’s computers—both in theory (Turing machines) and practice (PCs and smart phones)—are based on classical physics. However, modern quantum physics tells us that the world behaves quite differently. A quantum system can be in a superposition of many different states at the same time, and can exhibit interference effects during the course of its evolution.

Moreover, spatially separated quantum systems may be entangled with each other and operations may have ‘non-local” effects because of this. Quantum computation is the field that investigates the computational power and other properties of computers based on quantum-mechanical principles. Its main building block is the qubit which, unlike classical bits, can take both values 0 and 1 at the same time, and hence affords a certain kind of parallelism.

The laws of quantum mechanics constrain how we can perform computational operations on these qubits, and thus determine how efficiently we can solve a certain computational problem. Quantum computers generalize classical ones and hence are at least as efficient. However, the real aim is to find computational problems where a quantum computer is much more efficient than classical computers.’

Here is a lowdown on the recent breakthroughs and updates in the world of Quantum Computing:

**Creation of a quantum ‘Fredkin gate’**

On March 28, 2016, scientists at the Griffith University and the University of Queensland in Australia announced a crucial breakthrough in theĀ field of quantum computing with the creation of a quantum Fredkin gate- something that would make complicated logic operations a whole lot simpler. The research paper can be read here.

‘Much like our everyday computer, the brains of a quantum computer consist of chains of logic gates, although quantum logic gates harness quantum phenomena. Similar to building a huge wall out lots of small bricks, large quantum circuits require very many logic gates to function. However, if larger bricks are used the same wall could be built with far fewer bricks,’ said Raj Patel, who led the experiment with his team.

The experiment entailed using a specific type of quantum logic gate, known as the ‘Fredkin gate’, where two qubits are switched depending on the value of the third one. The experiment showed how larger quantum circuits could be build directly through photons, without requiring small logic gates

‘The quantum Fredkin gate can also be used to perform a direct comparison of two sets of qubits to determine whether they are the same or not. This is not only useful in computing but is an essential feature of some secure quantum communication protocols where the goal is to verify that two strings, or digital signatures, are the same,’ stated Timothy Ralph, co-author of the paper.

For long, computer scientists and physicists have aimed to develop quantum computers that are capable of performing operations several times faster than conventional computers. They have been mostly unsuccessful owing to the unstable nature of qubits. This new breakthrough certainly marks a step ahead in moving towards the technology of the future.

**Possibility of the first quantum data bus**

More recently on April 18, 2016, another major breakthrough was announced by scientists at RMIT University in Melbourne, Australia. The research group trialed a quantum processor that was capable of routing quantum information from different locations, thus demonstrating for the first time the perfect state transfer of an entangled qubit, on an integrated photonic device. This potentially paves the way towards the development of the ‘quantum data bus’, a key component of future quantum technologies.

‘The last 10 years has seen a wealth of theoretical proposals, but until now it has never been experimentally realized. Our device uses highly optimized quantum tunneling to relocate qubits between distant sites. It’s a breakthrough that has the potential to open up quantum computing in the near future,’ said Alberto Peruzzo, one of the researchers working on the project.

‘Quantum computers promise to solve vital tasks that are currently unmanageable on today’s standard computers and the need to delve deeper in this area has motivated a worldwide scientific and engineering effort to develop quantum technologies. It could make the critical difference for discovering new drugs, developing a perfectly secure quantum Internet and even improving facial recognition,’ added Peruzzo.

The latest findings, which show an experimental version of quantum tunneling to relocate qubits, could herald a radical change in quantum computing for future. With new findings and millions of investment in this field, we can look forward to living in a world that would possible alter our lifestyles with high speed dynamic processing power, saving time and money on various efforts.

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