Quantum RAM: Modelling the big questions with the very small

February 3, 2017, Griffith University
Quantum Optics and Information Lab, Joseph Ho. Credit: Griffith University

When it comes to studying transportation systems, stock markets and the weather, quantum mechanics is probably the last thing to come to mind. However, scientists at Australia's Griffith University and Singapore's Nanyang Technological University have just performed a 'proof of principle' experiment showing that when it comes to simulating such complex processes in the macroscopic world quantum mechanics can provide an unexpected advantage.

Griffith's Professor Geoff Pryde, who led the project, says that such processes could be simulated using a "quantum hard drive", much smaller than the required for conventional simulations.

"Stephen Hawking once stated that the 21st century is the 'century of complexity', as many of today's most pressing problems, such as understanding climate change or designing transportation system, involve huge networks of interacting components," he says.

"Their simulation is thus immensely challenging, requiring storage of unprecedented amounts of data. What our experiments demonstrate is a solution may come from , by encoding this data into a quantum system, such as the quantum states of light."

Einstein once said that "God does not play dice with the universe," voicing his disdain with the idea that contain intrinsic randomness.

"But theoretical studies showed that this intrinsic randomness is just the right ingredient needed to reduce the memory cost for modelling partially random statistics," says Dr Mile Gu, a member of the team who developed the initial theory.

In contrast with the usual binary storage system - the zeroes and ones of bits - quantum bits can be simultaneously 0 and 1, a phenomenon known as .

The researchers, in their paper published in Science Advances, say this freedom allows quantum computers to store many different states of the system being simulated in different superpositions, using less memory overall than in a classical computer.

The team constructed a proof-of-principle quantum simulator using a photon - a single particle of light - interacting with another photon.

They measured the memory requirements of this simulator, and compared it with the fundamental memory requirements of a classical simulator, when used to simulate specified partly random processes.

The data showed that the quantum system could complete the task with much less information stored than the classical computer- a factor of 20 improvements at the best point.

"Although the system was very small - even the ordinary simulation required only a single bit of memory - it proved that advantages can be achieved," Pryde says.

"Theoretically, large improvements can also be realized for much more complex simulations, and one of the goals of this research program is to advance the demonstrations to more complex problems."

Explore further: Quantum holograms as atomic scale memory keepsake

More information: "Experimentally modeling stochastic processes with less memory by the use of a quantum processor" Science Advances, advances.sciencemag.org/content/3/2/e1601302

Related Stories

Quantum holograms as atomic scale memory keepsake

October 21, 2014

Russian scientists have developed a theoretical model of quantum memory for light, adapting the concept of a hologram to a quantum system. These findings from Anton Vetlugin and Ivan Sokolov from St. Petersburg State University ...

How quantum physics could make 'The Matrix' more efficient

March 29, 2012

Researchers have discovered a new way in which computers based on quantum physics could beat the performance of classical computers. The work, by researchers based in Singapore and the UK, implies that a Matrix-like simulation ...

All quantum communication involves nonlocality

April 1, 2016

Researchers of CWI, University of Gdansk, Gdansk University of Technology, Adam Mickiewicz University and the University of Cambridge have proven that quantum communication is based on nonlocality. They show that whenever ...

Physicists demonstrate a quantum Fredkin gate

March 25, 2016

Researchers from Griffith University and the University of Queensland have overcome one of the key challenges to quantum computing by simplifying a complex quantum logic operation. They demonstrated this by experimentally ...

Recommended for you

Neutron stars may hold an answer to neutron puzzle on Earth

August 15, 2018

According to University of Illinois physicist Douglas H. Beck, "Neutrons play some unusual roles in our world. Free neutrons decay in about 900 s but, bound in nuclei, they are stable and make up somewhat more than half the ...

When mixing granular matter, order among disorder

August 14, 2018

Mixing liquids is easy, or at least scientifically understood: a drop of food coloring will eventually mix into a cup of water through diffusion, and a dollop of cream can be mixed into coffee with a spoon through what is ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.