Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International

Wikipedia Affiliate Button

Home > Press > Researchers reverse the flow of time on IBM's quantum computer

Image shows a time reversal procedure for a spreading wave packet that represents a quantum particle. The reversed state freely evolves into the original squeezed state, which is recovered with some precision -- in this case, 85 percent. (Image by Argonne National Laboratory.

CREDIT
Argonne National Laboratory
Image shows a time reversal procedure for a spreading wave packet that represents a quantum particle. The reversed state freely evolves into the original squeezed state, which is recovered with some precision -- in this case, 85 percent. (Image by Argonne National Laboratory. CREDIT Argonne National Laboratory

Abstract:
We all mark days with clocks and calendars, but perhaps no timepiece is more immediate than a mirror. The changes we notice over the years vividly illustrate science's "arrow of time" -- the likely progression from order to disorder. We cannot reverse this arrow any more than we can erase all our wrinkles or restore a shattered teacup to its original form.

Researchers reverse the flow of time on IBM's quantum computer

Argonne, IL | Posted on March 14th, 2019

Or can we?

An international team of scientists led by the U.S. Department of Energy's (DOE) Argonne National Laboratory explored this question in a first-of-its-kind experiment, managing to return a computer briefly to the past. The results, published March 13 in the journal Scientific Reports, suggest new paths for exploring the backward flow of time in quantum systems. They also open new possibilities for quantum computer program testing and error correction.

A quantum computer able to effectively jump back and clean up errors as it works could operate far more efficiently.

To achieve the time reversal, the research team developed an algorithm for IBM's public quantum computer that simulates the scattering of a particle. In classical physics, this might appear as a billiard ball struck by a cue, traveling in a line. But in the quantum world, one scattered particle takes on a fractured quality, spreading in multiple directions. To reverse its quantum evolution is like reversing the rings created when a stone is thrown into a pond.

In nature, restoring this particle back to its original state -- in essence, putting the broken teacup back together -- is impossible.

The main problem is that you would need a "supersystem," or external force, to manipulate the particle's quantum waves at every point. But, the researchers note, the timeline required for this supersystem to spontaneously appear and properly manipulate the quantum waves would extend longer than that of the universe itself.

Undeterred, the team set out to determine how this complexity might be overcome, at least in principle. Their algorithm simulated an electron scattering by a two-level quantum system, "impersonated" by a quantum computer qubit -- the basic unit of quantum information -- and its related evolution in time. The electron goes from a localized, or "seen," state, to a scattered one. Then the algorithm throws the process in reverse, and the particle returns to its initial state -- in other words, it moves back in time, if only by a tiny fraction of a second.

Given that quantum mechanics is governed by probability rather than certainty, the odds for achieving this time-travel feat were pretty good: The algorithm delivered the same result 85 percent of the time in a two-qubit quantum computer.

"We did what was considered impossible before," said Argonne senior scientist Valerii Vinokur, who led the research.

The result deepens our understanding of how the second law of thermodynamics -- that a system will always move from order to entropy and not the other way around -- acts in the quantum world. The researchers demonstrated in previous work that, by teleportating information, a local violation of the second law was possible in a quantum system separated into remote parts that could balance each other out.

"The results also give a nod to the idea that irreversibility results from measurement, highlighting the role that the concept of "measurement" plays in the very foundation of quantum physics," said article coauthor Gordey Lesovik of the Moscow Institute of Physics and Technology.

This is the same notion Austrian physicist Erwin Schrödinger captured with his famous thought experiment, in which a cat sealed in a box might remain both dead and alive until its status is monitored somehow. The researchers suspended their particle in this superposition, or form of quantum limbo, by limiting their measurements.

"This was the essential part of our algorithm," Vinokur said. "We measured the state of the system in the very beginning and at the very end, but did not interfere in the middle."

The finding may eventually enable better methods of error correction on quantum computers, where accumulated glitches generate heat and beget new ones. A quantum computer able to effectively jump back and clean up errors as it works could operate far more efficiently.

"At this moment, it's very hard to imagine all the implications this can have," Vinokur said. "I am optimistic, and I believe that it will be many."

The study also begs the question, can the researchers now figure out a way to make older folks young again? "Maybe," Vinokur jokes, "with the proper funding."

###

The work was done by international team including researchers from the Moscow Institute of Physics and Technology (Gordey Lesovik, Andrey Lebedev, Mikhail Suslov), ETH Zurich (Andrey Lebedev) and Argonne National Laboratory, U.S. (Valerii Vinokur, Ivan Sadovskyy).

Funding for this research was provided by the DOE Office of Science and Strategic Partnership Projects (Swiss National Foundation and the Foundation for the Advancement of Theoretical Physics "BASIS").

####

About Argonne National Laboratory
Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation's first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America's scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy's Office of Science.

The U.S. Department of Energy's Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit the Office of Science website.

For more information, please click here

Contacts:
Chris Kramer

630-252-5580

Copyright © Argonne National Laboratory

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

RELATED JOURNAL ARTICLE:

Related News Press

Quantum Physics

Data science helps engineers discover new materials for solar cells and LEDs May 24th, 2019

News and information

Big energy savings for tiny machines May 24th, 2019

Light and nanotechnology combined to prevent biofilms on medical implants May 24th, 2019

Scientists break record for highest-temperature superconductor: Experiment produces new material that can conduct electricity perfectly May 24th, 2019

Good vibrations: Using piezoelectricity to ensure hydrogen sensor sensitivity May 24th, 2019

Rice U. lab grows stable, ultrathin magnets: Rare iron oxide could be combined with 2D materials for electronic, spintronic devices May 24th, 2019

Laboratories

Rice U. lab grows stable, ultrathin magnets: Rare iron oxide could be combined with 2D materials for electronic, spintronic devices May 24th, 2019

Machine learning speeds modeling of experiments aimed at capturing fusion energy on Earth May 17th, 2019

Physics

New data on ultrafast electron photoemission from metallic nanostructures obtained: The results of the Russian-Japanese experiment explain the mechanism of electron photoemission by metallic nanostructures under ultrafast laser excitation May 23rd, 2019

Neutrons unlock the secrets of limoncello May 21st, 2019

Machine learning speeds modeling of experiments aimed at capturing fusion energy on Earth May 17th, 2019

Govt.-Legislation/Regulation/Funding/Policy

Data science helps engineers discover new materials for solar cells and LEDs May 24th, 2019

Scientists break record for highest-temperature superconductor: Experiment produces new material that can conduct electricity perfectly May 24th, 2019

Good vibrations: Using piezoelectricity to ensure hydrogen sensor sensitivity May 24th, 2019

Rice U. lab grows stable, ultrathin magnets: Rare iron oxide could be combined with 2D materials for electronic, spintronic devices May 24th, 2019

Quantum Computing

Manipulating atoms one at a time with an electron beam: New method could be useful for building quantum sensors and computers May 17th, 2019

Generating high-quality single photons for quantum computing: New dual-cavity design emits more single photons that can carry quantum information at room temperature May 17th, 2019

Computing faster with quasi-particles May 10th, 2019

Coincidence helps with quantum measurements: New method enables quantum simulations on larger systems April 22nd, 2019

Discoveries

Big energy savings for tiny machines May 24th, 2019

Light and nanotechnology combined to prevent biofilms on medical implants May 24th, 2019

Scientists break record for highest-temperature superconductor: Experiment produces new material that can conduct electricity perfectly May 24th, 2019

Good vibrations: Using piezoelectricity to ensure hydrogen sensor sensitivity May 24th, 2019

Announcements

Big energy savings for tiny machines May 24th, 2019

Light and nanotechnology combined to prevent biofilms on medical implants May 24th, 2019

Scientists break record for highest-temperature superconductor: Experiment produces new material that can conduct electricity perfectly May 24th, 2019

Good vibrations: Using piezoelectricity to ensure hydrogen sensor sensitivity May 24th, 2019

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

Data science helps engineers discover new materials for solar cells and LEDs May 24th, 2019

Quantum rebar: Quantum dots enhance stability of solar-harvesting perovskite crystals: Researchers demonstrate that perovskite crystals and quantum dots working together can increase stability of solar materials May 24th, 2019

Scientists break record for highest-temperature superconductor: Experiment produces new material that can conduct electricity perfectly May 24th, 2019

Good vibrations: Using piezoelectricity to ensure hydrogen sensor sensitivity May 24th, 2019

Grants/Sponsored Research/Awards/Scholarships/Gifts/Contests/Honors/Records

Data science helps engineers discover new materials for solar cells and LEDs May 24th, 2019

Rice U. lab grows stable, ultrathin magnets: Rare iron oxide could be combined with 2D materials for electronic, spintronic devices May 24th, 2019

Artificial photosynthesis transforms carbon dioxide into liquefiable fuels May 22nd, 2019

Manipulating atoms one at a time with an electron beam: New method could be useful for building quantum sensors and computers May 17th, 2019

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project