New design of primitive quantum computer finds application

May 10, 2016

Scientists and engineers from the Universities of Bristol and Western Australia have developed how to efficiently simulate a "quantum walk" on a new design for a primitive quantum computer.

Quantum computers have significant potential to open entirely new directions for processing information and to overhaul the way that we think about and use the science of computation. Modern computers already play a huge role in society -- they routinely handle and process vast amounts of data and solve calculations at an incredible rate. However, there are some problems that they just cannot solve in a useful amount of time, no matter how fast they become. The concept of a quantum computer aims to address this, exploring uncharted computation and solving at least some of these problems that classical computers cannot.

The study published today in Nature Communications, reports strong evidence that with this method something meaningful can already be seen with a primitive quantum computer that cannot be seen with a classical computer. The very first steps towards this have been implemented in the lab in Bristol.

Dr Ashley Montanaro, Lecturer in Applied Mathematics and EPSRC Fellow from the University of Bristol's School of Mathematics, said: "A quantum computer is a machine designed to use quantum mechanics to solve problems more efficiently than any possible classical computer.

"We know some algorithms that can run on such machines and it's an open and exciting challenge to find more. But most of the quantum algorithms we know need to be run on a large-scale quantum computer to see a speed up."

Building a large-scale quantum computer is one of the biggest engineering challenges today. There's a growing worldwide effort to develop one and it needs substantial effort from a wide range of expertise - including as part of the UK National Quantum Technologies Programme (UKNQT). The results could be tremendous, offering fast and cheap ways to design new materials and new pharmaceuticals.

But there is a field of research emerging now that can help accelerate understanding how quantum computers will work and how users can apply them. Examining the power of smaller, more primitive designs for quantum computers indicates that sooner than we thought, quantum machines could outperform the capabilities of classical computing for very specific tasks -- "Boson Sampling" is a recent example that is driven by what is experimentally available very soon.

Big questions researchers face include what can these primitive quantum processors do that is useful to someone and how sophisticated do they need to be. The results published in today's paper help to answer this question, by looking at how to simulate particular kinds of a phenomenon called the quantum walk.

The quantum walk at first glance is abstract. But it is the quantum mechanical version of very useful models such as Brownian motion and the "drunken sailor's random walk". The key difference is the particle in the quantum walk is endowed with the principle of quantum superposition. This has enabled other researchers to show they are a new way to think about how full-scale quantum computers might operate and to create useful quantum algorithms.

Xiaogang Qiang, PhD student in the School of Physics who implemented the experiment, said: "It's like the particle can explore space in parallel. This parallelism is key to quantum algorithms, based on quantum walks that search huge databases more efficiently than we can currently."

Dr Jonathan Matthews, EPSRC Early Career Fellow and Lecturer in the School of Physics and the Centre for Quantum Photonics, explained: "An exciting outcome of our work is that we may have found a new example of quantum walk physics that we can observe with a primitive quantum computer, that otherwise a classical computer could not see.

"These otherwise hidden properties have practical use, perhaps in helping to design more sophisticated quantum computers."
-end-
Paper

'Efficient quantum walk on a quantum processor' [open access] by Xiaogang Qiang, Thomas Loke, Ashley Montanaro, Kanin Aungskunsiri, Xiaoqi Zhou, Jeremy L. O'Brien, Jingbo Wang, Jonathan C. F. Matthews in Nature Communications

University of Bristol

Related Quantum Computers Articles from Brightsurf:

Optical wiring for large quantum computers
Researchers at ETH have demonstrated a new technique for carrying out sensitive quantum operations on atoms.

New algorithm could unleash the power of quantum computers
A new algorithm that fast forwards simulations could bring greater use ability to current and near-term quantum computers, opening the way for applications to run past strict time limits that hamper many quantum calculations.

A new technique prevents errors in quantum computers
A paper recently published in Nature presents a protocol allowing for the error detection and the protection of quantum processors in case of qubit loss.

New method prevents quantum computers from crashing
Quantum information is fragile, which is why quantum computers must be able to correct errors.

Natural radiation can interfere with quantum computers
Radiation from natural sources in the environment can limit the performance of superconducting quantum bits, known as qubits.

New model helps to describe defects and errors in quantum computers
A summer internship in Bilbao, Spain, has led to a paper in the journal Physical Review Letters for Jack Mayo, a Master's student at the University of Groningen, the Netherlands.

The first intuitive programming language for quantum computers
Several technical advances have been achieved recently in the pursuit of powerful quantum computers.

Hot qubits break one of the biggest constraints to practical quantum computers
A proof-of-concept published today in Nature promises warmer, cheaper and more robust quantum computing.

Future quantum computers may pose threat to today's most-secure communications
Quantum computers that are exponentially faster than any of our current classical computers and are capable of code-breaking applications could be available in 12 to 15 years, posing major risks to the security of current communications systems, according to a new RAND Corporation report.

Novel error-correction scheme developed for quantum computers
Experimental quantum computers are plagued with errors. Here Dr Arne Grimsmo from the University of Sydney and colleagues from RMIT and the University of Queensland offer a novel method to reduce errors in a scheme applicable across different types of quantum hardware.

Read More: Quantum Computers News and Quantum Computers Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.