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Primeur weekly 2018-03-05

Quantum computing

Want more efficient simulators? Store time in a quantum superposition ...

Experimentally demonstrated a toffoli gate in a semiconductor three-qubit system ...

Individual quantum dots imaged in 3D for first time ...

Artificial intelligence techniques reconstruct mysteries of quantum systems ...

Majorana runners go long range: New topological phases of matter unveiled ...

Focus on Europe

University of Groningen to organize Second Information Universe Conference ...

IEEE eScience 2018 calls for contributions ...

Harvey Meyer is awarded an ERC Consolidator Grant for fundamental calculations on strong interaction effects ...

BSC presents SuperGeek, a mascot to bring supercomputers closer to the youngest ...

Call for Participation to European Forum about "Shaping Europe's Digital Future - HPC for Extreme Scale Scientific and Industrial Applications" ...

Data management and computing infrastructure procurement broadly serves Finnish research ...

Hardware

High demand from commercial customers to boost growth in global supercomputer market ...

OCF deploys UK academia's first IBM POWER9 systems ...

Niagara is Canada's most powerful research supercomputer fuelling Canadian innovation and discovery ...

CENIC recognizes UCSC's Hyades supercomputer cluster connection ...

CoolIT Systems reports 60% revenue growth in 2017 ...

SPEC offers HPG benchmarks free of charge to qualified non-profit organisations worldwide ...

Applications

Supercomputer model reveals how sticky tape makes graphene ...

Concertio launches Optimizer Studio to help performance engineers and IT professionals achieve peak system performance ...

Sandia researcher Jacqueline Chen elected to National Academy of Engineering ...

Oak Ridge National Laboratory uses supercomputers to simulate radiation transport and to understand the dynamic interactions among ions, solids and liquids ...

Mining hardware helps scientists gain insight into silicon nanoparticles ...

Can strongly lensed type 1a supernovae resolve cosmology's biggest controversy? ...

Give your research a boost at the SURF Research Bootcamp ...

TOP500

Supercomputing under a new lens: A Sandia-developed benchmark re-ranks top computers ...

The Cloud

Alibaba Cloud launches Cloud and AI solutions in Europe including bare metal HPC services ...

KIT helps build the European Open Science Cloud ...

Want more efficient simulators? Store time in a quantum superposition


This is an artist's render of a quantum timekeeper, in which time is tracked through superposition states. Credit: Mile Gu / Centre for Quantum Technologies.
2 Mar 2018 Singapore - Computer models of systems such as a city's traffic flow or neural firing in the brain tends to use up a lot of memory. But a new approach with quantum simulators could significantly cut that memory use by taking a quantum approach to time, suggest researchers in Singapore.

The suggestion comes from researchers Mile Gu and Thomas Elliott in Singapore, who describe their proposal in a paper published 1 March innpj Quantum Information. Mile Gu works at the Centre for Quantum Technologies and Nanyang Technological University (NTU) in Singapore, and Thomas Elliott is at NTU.

To perform a simulation, a classical computer must cut time into discrete steps. Mile Gu draws analogy with an ancient way of measuring time: the hourglass. "Zoom in on an hourglass and one can see the individual grains of sand falling one by one. It's a granular flow", stated Mile Gu.

Just as the hourglass needs finer sand to make a more precise measurement of time, a computer needs finer time-steps to make more accurate simulations. In fact, the ideal would be to simulate time continuously because, to the best of our observations, time appears to be continuous. But that implies a truly accurate classical simulation would need infinite memory to run such a programme.

While that's impossible with a classical computer, quantum effects provide a work-around. "With a quantum simulator, you can avoid the precision versus storage trade-off that you have to suffer with a classical device", explained Thomas Elliott.

To explain how it works, imagine you need to catch a bus. If you arrive at the stop just in time to see a bus leaving, you now expect the next bus to take longer to arrive than if you hadn't just seen one leave. That's because the probability of a bus coming isn't always constant, but depends on how long it has been since the last bus.

To simulate similar processes where probability changes over time, a regular computer calculates outcomes at set time intervals. It might, for example, divide the probabilities for bus arrival times into 30 second intervals, updating those probabilities after each interval depending on whether a bus arrived (or didn't). To be more precise about when a bus will come, or to accurately model bigger, more complicated traffic networks, needs smaller time steps and thus more memory.

In this classical approach, one makes predictions by counting how much time has elapsed since the previous bus. This seems logical, and it turns out to be the best classical method. Quantum physics, however, allows a completely different approach.

A quantum simulator can be in many different states at the same time, each with its own probability of being realised. This is a phenomenon known as quantum superposition. Mile Gu and Thomas Elliott's proposal is to encode the temporal probability distribution for the event they want to simulate into the probability weighting of the different states. If the superposition is created in a property such as the position of a particle, which can itself evolve continuously, time can then be tracked continuously too. So it is possible to discard some information about the elapsed time - achieving superior memory-efficiency - without sacrificing predictive accuracy.

The gain does come at the expense of losing knowledge of the past. The elapsed time - a record of the past, in other words - cannot be recovered exactly from the superposition, but all forecasting ability is retained nonetheless.

"Ultimately, when making predictions we don't care about what we have already seen. Rather, we care only for what these observations tell us about what we expect to see next. Quantum physics allows us to efficiently isolate this information", stated Thomas Elliott.

The paper titled " Superior memory efficiency of quantum devices for the simulation of continuous-time stochastic processes " has appeared innpj Quantum Information4, 18 (2018).

Source: Centre for Quantum Technologies at the National University of Singapore

Back to Table of contents

Primeur weekly 2018-03-05

Quantum computing

Want more efficient simulators? Store time in a quantum superposition ...

Experimentally demonstrated a toffoli gate in a semiconductor three-qubit system ...

Individual quantum dots imaged in 3D for first time ...

Artificial intelligence techniques reconstruct mysteries of quantum systems ...

Majorana runners go long range: New topological phases of matter unveiled ...

Focus on Europe

University of Groningen to organize Second Information Universe Conference ...

IEEE eScience 2018 calls for contributions ...

Harvey Meyer is awarded an ERC Consolidator Grant for fundamental calculations on strong interaction effects ...

BSC presents SuperGeek, a mascot to bring supercomputers closer to the youngest ...

Call for Participation to European Forum about "Shaping Europe's Digital Future - HPC for Extreme Scale Scientific and Industrial Applications" ...

Data management and computing infrastructure procurement broadly serves Finnish research ...

Hardware

High demand from commercial customers to boost growth in global supercomputer market ...

OCF deploys UK academia's first IBM POWER9 systems ...

Niagara is Canada's most powerful research supercomputer fuelling Canadian innovation and discovery ...

CENIC recognizes UCSC's Hyades supercomputer cluster connection ...

CoolIT Systems reports 60% revenue growth in 2017 ...

SPEC offers HPG benchmarks free of charge to qualified non-profit organisations worldwide ...

Applications

Supercomputer model reveals how sticky tape makes graphene ...

Concertio launches Optimizer Studio to help performance engineers and IT professionals achieve peak system performance ...

Sandia researcher Jacqueline Chen elected to National Academy of Engineering ...

Oak Ridge National Laboratory uses supercomputers to simulate radiation transport and to understand the dynamic interactions among ions, solids and liquids ...

Mining hardware helps scientists gain insight into silicon nanoparticles ...

Can strongly lensed type 1a supernovae resolve cosmology's biggest controversy? ...

Give your research a boost at the SURF Research Bootcamp ...

TOP500

Supercomputing under a new lens: A Sandia-developed benchmark re-ranks top computers ...

The Cloud

Alibaba Cloud launches Cloud and AI solutions in Europe including bare metal HPC services ...

KIT helps build the European Open Science Cloud ...