Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Could a demon help to create a quantum computer? Physicists implement a version of Maxwell's famous thought experiment for reducing entropy

Reducing entropy in a randomly half-filled 5x5x5 lattice of atoms. Each row shows a snapshot of the 5 planes in the lattice. The top row shows the initial random distribution of atoms among the 3D array of 125 possible sites. The second row show the distributions of atoms after the first sort and the third row shows the distribution after the second sort, at which point the target 5x5x2 sublattice is completely filled. This process reduces the entropy in the system by a factor of about 2.4.

CREDIT
Weiss Laboratory, Penn State
Reducing entropy in a randomly half-filled 5x5x5 lattice of atoms. Each row shows a snapshot of the 5 planes in the lattice. The top row shows the initial random distribution of atoms among the 3D array of 125 possible sites. The second row show the distributions of atoms after the first sort and the third row shows the distribution after the second sort, at which point the target 5x5x2 sublattice is completely filled. This process reduces the entropy in the system by a factor of about 2.4. CREDIT Weiss Laboratory, Penn State

Abstract:
Reduced entropy in a three-dimensional lattice of super-cooled, laser-trapped atoms could help speed progress toward creating quantum computers. A team of researchers at Penn State can rearrange a randomly distributed array of atoms into neatly organized blocks, thus performing the function of a "Maxwell's demon"--a thought experiment from the 1870s that challenged the second law of thermodynamics. The organized blocks of atoms could form the basis for a quantum computer that uses uncharged atoms to encode data and perform calculations. A paper describing the research appears September 6, 2018 in the journal Nature.

Could a demon help to create a quantum computer? Physicists implement a version of Maxwell's famous thought experiment for reducing entropy

University Park, PA | Posted on September 5th, 2018

"Traditional computers use transistors to encode data as bits that can be in one of two states--zero or one," said David Weiss, professor of physics at Penn State and the leader of the research team. "We are devising quantum computers that use atoms as 'quantum bits' or 'qubits' that can encode data based on quantum mechanical phenomena that allow them to be in multiple states simultaneously. Organizing the atoms into a packed 3D grid allows us to fit a lot of atoms into a small area and makes computation easier and more efficient."

The second law of thermodynamics states that the entropy--sometimes thought of as disorder--of a system cannot decrease over time. One of the consequences of this law is that it precludes the possibility of a perpetual motion device. Around 1870, James Clerk Maxwell proposed a thought experiment in which a demon could open and close a gate between two chambers of gas, allowing warmer atoms to pass in one direction and cooler atoms to pass in the other. This sorting, which required no energy input, would result in a reduction of entropy in the system and a temperature difference between the two chambers that could be used as a heat pump to perform work, thus violating the second law.

"Later work has shown that the demon doesn't actually violate the second law and subsequently there have been many attempts to devise experimental systems that behave like the demon," said Weiss. "There have been some successes at very small scales, but we've created a system in which we can manipulate a large number of atoms, organizing them in a way that reduces the system's entropy, just like the demon."

The researchers use lasers to trap and cool atoms in a three-dimensional lattice with 125 positions arranged as a 5 by 5 by 5 cube. They then randomly fill about half of the positions in the lattice with atoms. By adjusting the polarization of the laser traps, the researchers can move atoms individually or in groups, reorganizing the randomly distributed atoms to fully fill either 5 by 5 by 2 or 4 by 4 by 3 subsets of the lattice.

"Because the atoms are cooled to almost as low a temperature as possible, the entropy of the system is almost entirely defined by the random configuration of the atoms within the lattice," said Weiss. "In systems where the atoms are not super-cooled, the vibration of the atoms makes up the majority of the system's entropy. In such a system, organizing the atoms does little to change the entropy, but in our experiment, we show that organizing the atoms lowers the entropy within the system by a factor of about 2.4."

###

In addition to Weiss, the research team at Penn State includes Aishwarya Kumar, Tsung-Yao Wu, and Felipe Giraldo Mejia. The research was funded by the U.S. National Science Foundation.

####

For more information, please click here

Contacts:
Sam Sholtis

814-865-1390

Copyright © Penn State

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 News Press

News and information

NUS researchers invent new test kit for quick, accurate and low-cost screening of diseases: Test results are denoted by a color change and could be further analyzed by a smartphone app, making it attractive as a point-of-care diagnostic device September 19th, 2018

Silver nanoparticles are toxic for aquatic organisms: A research team at the UPV/EHU-University of the Basque Country has analysed how zebrafish are affected in the long term by exposure to silver particles September 19th, 2018

Leti Announces EU Project to Develop Powerful, Inexpensive Sensors with Photonic Integrated Circuits: REDFINCH Members Initially Targeting Applications for Gas Detection and Analysis For Refineries & Petrochemical Industry and Protein Analysis for Dairy Industry September 19th, 2018

Researchers develop microbubble scrubber to destroy dangerous biofilms September 19th, 2018

Quantum Physics

Tiny camera lens may help link quantum computers to network September 14th, 2018

September 5th, 2018

A Novel Graphene Quantum Dot Structure Takes the Cake August 24th, 2018

How hot is Schrödinger's coffee? August 15th, 2018

Govt.-Legislation/Regulation/Funding/Policy

Researchers develop microbubble scrubber to destroy dangerous biofilms September 19th, 2018

Researchers managed to prevent the disappearing of quantum information September 14th, 2018

New photonic chip promises more robust quantum computers September 14th, 2018

Ultracold atoms used to verify 1963 prediction about 1D electrons: Rice University, University of Geneva study focuses on theory that's increasingly relevant to chipmakers September 5th, 2018

Possible Futures

NUS researchers invent new test kit for quick, accurate and low-cost screening of diseases: Test results are denoted by a color change and could be further analyzed by a smartphone app, making it attractive as a point-of-care diagnostic device September 19th, 2018

Silver nanoparticles are toxic for aquatic organisms: A research team at the UPV/EHU-University of the Basque Country has analysed how zebrafish are affected in the long term by exposure to silver particles September 19th, 2018

Leti Announces EU Project to Develop Powerful, Inexpensive Sensors with Photonic Integrated Circuits: REDFINCH Members Initially Targeting Applications for Gas Detection and Analysis For Refineries & Petrochemical Industry and Protein Analysis for Dairy Industry September 19th, 2018

Researchers develop microbubble scrubber to destroy dangerous biofilms September 19th, 2018

Chip Technology

Researchers managed to prevent the disappearing of quantum information September 14th, 2018

New devices based on rust could reduce excess heat in computers: Physicists explore long-distance information transmission in antiferromagnetic iron oxide September 14th, 2018

New photonic chip promises more robust quantum computers September 14th, 2018

How a tetrahedral substance can be more symmetrical than a spherical atom: A new type of symmetry September 14th, 2018

Quantum Computing

Researchers managed to prevent the disappearing of quantum information September 14th, 2018

Tiny camera lens may help link quantum computers to network September 14th, 2018

New photonic chip promises more robust quantum computers September 14th, 2018

A Novel Graphene Quantum Dot Structure Takes the Cake August 24th, 2018

Discoveries

NUS researchers invent new test kit for quick, accurate and low-cost screening of diseases: Test results are denoted by a color change and could be further analyzed by a smartphone app, making it attractive as a point-of-care diagnostic device September 19th, 2018

Silver nanoparticles are toxic for aquatic organisms: A research team at the UPV/EHU-University of the Basque Country has analysed how zebrafish are affected in the long term by exposure to silver particles September 19th, 2018

Researchers develop microbubble scrubber to destroy dangerous biofilms September 19th, 2018

New photonic chip promises more robust quantum computers September 14th, 2018

Announcements

NUS researchers invent new test kit for quick, accurate and low-cost screening of diseases: Test results are denoted by a color change and could be further analyzed by a smartphone app, making it attractive as a point-of-care diagnostic device September 19th, 2018

Silver nanoparticles are toxic for aquatic organisms: A research team at the UPV/EHU-University of the Basque Country has analysed how zebrafish are affected in the long term by exposure to silver particles September 19th, 2018

Leti Announces EU Project to Develop Powerful, Inexpensive Sensors with Photonic Integrated Circuits: REDFINCH Members Initially Targeting Applications for Gas Detection and Analysis For Refineries & Petrochemical Industry and Protein Analysis for Dairy Industry September 19th, 2018

Researchers develop microbubble scrubber to destroy dangerous biofilms September 19th, 2018

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

NUS researchers invent new test kit for quick, accurate and low-cost screening of diseases: Test results are denoted by a color change and could be further analyzed by a smartphone app, making it attractive as a point-of-care diagnostic device September 19th, 2018

Silver nanoparticles are toxic for aquatic organisms: A research team at the UPV/EHU-University of the Basque Country has analysed how zebrafish are affected in the long term by exposure to silver particles September 19th, 2018

Researchers develop microbubble scrubber to destroy dangerous biofilms September 19th, 2018

New devices based on rust could reduce excess heat in computers: Physicists explore long-distance information transmission in antiferromagnetic iron oxide September 14th, 2018

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