Nav: Home

Simulating quantum systems with neural networks

July 01, 2019

Even on the scale of everyday life, nature is governed by the laws of quantum physics. These laws explain common phenomena like light, sound, heat, or even the trajectories of balls on a pool table. But when applied to a large number of interacting particles, the laws of quantum physics actually predict a variety of phenomena that defy intuition.

In order to study quantum systems made of many particles, physicists must first be able to simulate them. This can be done by solving the equations describing their inner workings on supercomputers. But while Moore's Law predicts that the processing power of computers doubles every couple of years, this is a far cry from the power needed to tackle the challenges of quantum physics.

The reason is that predicting the properties of a quantum system is enormously complex, demanding a computational power that grows exponentially with the size of the quantum system - an "intrinsically complex" task, according to Professor Vincenzo Savona, who directs the Laboratory of Theoretical Physics of Nanosystems at EPFL.

"Things become even more complicated when the quantum system is open, meaning that it is subject to the disturbances of its surrounding environment," Savona adds. And yet, tools to efficiently simulate open quantum systems are much needed, as most modern experimental platforms for quantum science and technology are open systems, and physicists are constantly in search of new ways to simulate and benchmark them.

But significant progress has been made thanks to a new computational method that simulates quantum systems with neural networks. The method was developed by Savona and his PhD student Alexandra Nagy at EPFL - and independently by scientists at Université Paris Diderot, the Heriot-Watt University in Edinburgh, and the Flatiron Institute in New York. The total body of work is being published across three papers in Physical Review Letters.

"We basically combined advances in neural networks and machine-learning with quantum Monte Carlo tools," says Savona, referring to a large toolkit of computational methods that physicists use to study complex quantum systems. The scientists trained a neural network to represent simultaneously the many quantum states in which a quantum system can be cast by the influence of its environment.

The neural-network approach allowed the physicists to predict the properties of quantum systems of considerable size and arbitrary geometry. "This is a novel computational approach that addresses the problem of open quantum systems with versatility and a lot of potential for scaling up," says Savona. The method is set to become a tool of choice for the study of complex quantum systems, and, looking a bit more into the future, for assessing the effects of noise on quantum hardware.

Alexandra Nagy, Vincenzo Savona. Variational quantum Monte Carlo with neural network ansatz for open quantum systems. Physical Review Letters Phys. Rev. Lett. 122, 250501 (2019). DOI: 10.1103/PhysRevLett.122.250501

Ecole Polytechnique Fédérale de Lausanne

Related Quantum Physics Articles:

A new quantum data classification protocol brings us nearer to a future 'quantum internet'
A new protocol created by researchers at the Universitat Autònoma de Barcelona sorts and classifies quantum data by the state in which they were prepared, with more efficiency than the equivalent classical algorithm.
Quantum physics: Ménage à trois photon-style
When two photons become entangled, the quantum state of the first will correlate perfectly with the quantum state of the second.
Quantum physics -- Simulating fundamental interactions with ultracold atoms
An international team of physicists succeeded in precisely engineering key ingredients to simulate a specific lattice gauge theory using ultracold atoms in optical lattices.
A key piece to understanding how quantum gravity affects low-energy physics
In a new study, led by researchers from SISSA (Scuola Internazionale Superiore di Studi Avanzati), the Complutense University of Madrid and the University of Waterloo, a solid theoretical framework is provided to discuss modifications to the Unruh effect caused by the microstructure of space-time.
Helping physics teachers who don't know physics
A shortage of high school physics teachers has led to teachers with little-to-no training taking over physics classrooms, reports show.
Quantum physics and origami for the ultimate get-well card
The bizarre optical properties of tiny metal particles -- smaller than light waves -- can be captured on paper to detect even a single target molecule in a test sample.
Can artificial intelligence solve the mysteries of quantum physics?
A new study published in Physical Review Letters by Prof.
Brilliant glow of paint-on semiconductors comes from ornate quantum physics
A new wave of semiconductors that can be painted on is on the horizon.
New device could help answer fundamental questions about quantum physics
Researchers have developed a new device that can measure and control a nanoparticle trapped in a laser beam with unprecedented sensitivity.
Breakthrough in quantum physics
Researchers from Graz University of Technology have described for the first time the dynamics which takes place within a trillionth of a second after photoexcitation of a single atom inside a superfluid helium nanodroplet.
More Quantum Physics News and Quantum Physics Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

Why do we revere risk-takers, even when their actions terrify us? Why are some better at taking risks than others? This hour, TED speakers explore the alluring, dangerous, and calculated sides of risk. Guests include professional rock climber Alex Honnold, economist Mariana Mazzucato, psychology researcher Kashfia Rahman, structural engineer and bridge designer Ian Firth, and risk intelligence expert Dylan Evans.
Now Playing: Science for the People

#541 Wayfinding
These days when we want to know where we are or how to get where we want to go, most of us will pull out a smart phone with a built-in GPS and map app. Some of us old timers might still use an old school paper map from time to time. But we didn't always used to lean so heavily on maps and technology, and in some remote places of the world some people still navigate and wayfind their way without the aid of these tools... and in some cases do better without them. This week, host Rachelle Saunders...
Now Playing: Radiolab

Dolly Parton's America: Neon Moss
Today on Radiolab, we're bringing you the fourth episode of Jad's special series, Dolly Parton's America. In this episode, Jad goes back up the mountain to visit Dolly's actual Tennessee mountain home, where she tells stories about her first trips out of the holler. Back on the mountaintop, standing under the rain by the Little Pigeon River, the trip triggers memories of Jad's first visit to his father's childhood home, and opens the gateway to dizzying stories of music and migration. Support Radiolab today at