Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International

Wikipedia Affiliate Button

Home > Press > When superconductivity disappears in the core of a quantum tube: By replacing the electrons with ultra-cold atoms, a group of physicists has created a perfectly clean material, unveiling new states of matter at the quantum level

In a one-dimensional periodic potential, represented here by a Toblerone bar, there is no flow of electrons (represented by Gummy bears) when two of them occupy a hollow space. The research made it possible to observe similar behaviour with ultra-cold lithium-6 atoms.
CREDIT
© ETH Zurich
In a one-dimensional periodic potential, represented here by a Toblerone bar, there is no flow of electrons (represented by Gummy bears) when two of them occupy a hollow space. The research made it possible to observe similar behaviour with ultra-cold lithium-6 atoms. CREDIT © ETH Zurich

Abstract:
Predicting the behaviour of electrons in a material is not easily done. Physicists from the University of Geneva (UNIGE), ETH Zurich and EPFL replaced the electrons with ultra-cold neutral lithium atoms that they had circulated in a one-dimensional quantum tube. The scientists were then able to confirm an unusual state of matter that retains its insulation regardless of the level of attraction between the particles. This work, published in PRX, opens the way to the search for new materials with atypical properties.

When superconductivity disappears in the core of a quantum tube: By replacing the electrons with ultra-cold atoms, a group of physicists has created a perfectly clean material, unveiling new states of matter at the quantum level

Geneva, Switzerland | Posted on April 16th, 2018

The fact that a material is a metal or an insulator depends on a series of microscopic details, such as the strength of the interactions between electrons; the presence of impurities or obstacles; or the number of dimensions through which the charge carriers can propagate. This high degree of complexity means that predicting the electronic properties of a given material is a hard task. Even if we know perfectly how to model the trajectory of a particle in a vacuum, we struggle to do the same thing in a material (a crystal for example), where the electrons circulate between the nuclei of positively-charged atoms. The latter generate a periodic potential, much like a series of peaks that affect the motion of the electrons, thereby complicating predictions. Will the material be a metal? An insulator? Or a semiconductor? It will all depend on two parameters: the strength of the interaction between the electrons and the strength of the periodic potential. The answer to these questions was found in the ongoing discussions and debates between a group of theorists, led by Thierry Giamarchi, professor in the Department of Quantum Matter Physics (physics section) in UNIGE's Faculty of Sciences, and the experimental groups based in Zurich and Lausanne, led by Martin Lebrat, from the group headed by Professor Tilman Esslinger at ETH Zurich's Institute for Quantum Electronics; and by Jean-Philippe Brantut, professor at EPFL.

The coldest place in the Universe

The researchers tackled the problem by conducting their experiments on a perfectly clean artificial material, meaning they could control the interaction and the periodic potential. Instead of circulating electrons whose long-range interactions make predictions more difficult, the scientists used ultra-cold neutral lithium-6 atoms, which they stored using a laser in two borderless tanks, veritable «bowls of light». As Thierry Giamarchi explains: «The core of this experiment is the coldest place in the universe. The temperature there only reaches 70 billionths of a degree above absolute zero, which is much lower than in an interstellar vacuum.»

The atomic reservoirs were then connected by a one-dimensional quantum tube, in which a second laser was employed to simulate the «peaks» of the periodic potential. The researchers were able to measure the conductivity of the tube while varying the relevant parameters, including the length and height of the periodic potential together with the interactions between the particles passing through it. The scientists highlighted an unusual state of matter, predicted by the theory but which no one had been able to observe until then: a band insulator that is maintained regardless of the strength of the attractive interaction between the particles. The intuitive conclusion was that the greater the attraction between the particles, the more likely it was that the material would be a conductor or superconductor. «It's true,» continues Professor Giamarchi, «in a three-dimensional world but in the low-dimensional quantum world, it's an urban legend. When you manage to confine the material in a one-dimensional quantum tube with a periodic potential, it remains insulating, even if there is an infinite attraction.» The huge flexibility resulting from this research paves the way for creating complex structures. «We can see this system as a kind of simulator that will define the ingredients to be used to devise a material that does not yet exist, and that could meet the requirements for future electronic systems - in quantum computers, for example» says Giamarchi.

####

For more information, please click here

Contacts:
Thierry Giamarchi

41-223-796-363

Copyright © University of Geneva

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

News and information

Gold nanoparticles to facilitate in-situ detection of amplified DNA at room temperature March 21st, 2019

CEA-Leti Announces Prototype of Next-generation Photo-Acoustic Sensors for Gas Detection: REDFINCH Team Achieves These Capabilities in Mid-infrared Region, Where Many Important Chemical and Biological Species Have Strong Absorption Fingerprints March 21st, 2019

Fish-Inspired Material Changes Color Using Nanocolumns March 18th, 2019

New method to reduce uranium concentration in contaminated water March 18th, 2019

Quantum sensing method measures minuscule magnetic fields: MIT researchers find a new way to make nanoscale measurements of fields in more than one dimension March 15th, 2019

Quantum Physics

Quantum sensing method measures minuscule magnetic fields: MIT researchers find a new way to make nanoscale measurements of fields in more than one dimension March 15th, 2019

Researchers reverse the flow of time on IBM's quantum computer March 14th, 2019

When semiconductors stick together, materials go quantum: A new study led by Berkeley Lab reveals how aligned layers of atomically thin semiconductors can yield an exotic new quantum material March 12th, 2019

A quantum magnet with a topological twist: Materials with a kagome lattice pattern exhibit 'negative magnetism' and long-sought 'flat-band' electrons February 23rd, 2019

Superconductivity

When semiconductors stick together, materials go quantum: A new study led by Berkeley Lab reveals how aligned layers of atomically thin semiconductors can yield an exotic new quantum material March 12th, 2019

The moiré patterns of three layers change the electronic properties of graphene March 8th, 2019

Govt.-Legislation/Regulation/Funding/Policy

Fish-Inspired Material Changes Color Using Nanocolumns March 18th, 2019

Exotic “second sound” phenomenon observed in pencil lead: At relatively balmy temperatures, heat behaves like sound when moving through graphite, study reports March 15th, 2019

Researchers reverse the flow of time on IBM's quantum computer March 14th, 2019

When semiconductors stick together, materials go quantum: A new study led by Berkeley Lab reveals how aligned layers of atomically thin semiconductors can yield an exotic new quantum material March 12th, 2019

Possible Futures

Gold nanoparticles to facilitate in-situ detection of amplified DNA at room temperature March 21st, 2019

Fish-Inspired Material Changes Color Using Nanocolumns March 18th, 2019

New method to reduce uranium concentration in contaminated water March 18th, 2019

Exotic “second sound” phenomenon observed in pencil lead: At relatively balmy temperatures, heat behaves like sound when moving through graphite, study reports March 15th, 2019

Chip Technology

Exotic “second sound” phenomenon observed in pencil lead: At relatively balmy temperatures, heat behaves like sound when moving through graphite, study reports March 15th, 2019

Pushing Past Limits: Junkai Jiang receives prestigious Ph.D. Student Fellowship from IEEE Electron Devices Society March 14th, 2019

Nanometrics Announces $80 Million Share Repurchase Program March 14th, 2019

When semiconductors stick together, materials go quantum: A new study led by Berkeley Lab reveals how aligned layers of atomically thin semiconductors can yield an exotic new quantum material March 12th, 2019

Quantum Computing

Researchers reverse the flow of time on IBM's quantum computer March 14th, 2019

Researchers move closer to practical photonic quantum computing: New method fills critical need to measure large-scale quantum correlation of single photons February 28th, 2019

Media invited to open meeting on the future of quantum technology held at RIT Jan. 23-25: Leaders from NASA, NSF, NIST and Sandia National Laboratory to attend January 11th, 2019

Spintronics 'miracle material' put to the test: Physicists build devices using mineral perovskite January 11th, 2019

Discoveries

Gold nanoparticles to facilitate in-situ detection of amplified DNA at room temperature March 21st, 2019

CEA-Leti Announces Prototype of Next-generation Photo-Acoustic Sensors for Gas Detection: REDFINCH Team Achieves These Capabilities in Mid-infrared Region, Where Many Important Chemical and Biological Species Have Strong Absorption Fingerprints March 21st, 2019

Fish-Inspired Material Changes Color Using Nanocolumns March 18th, 2019

New method to reduce uranium concentration in contaminated water March 18th, 2019

Announcements

Gold nanoparticles to facilitate in-situ detection of amplified DNA at room temperature March 21st, 2019

CEA-Leti Announces Prototype of Next-generation Photo-Acoustic Sensors for Gas Detection: REDFINCH Team Achieves These Capabilities in Mid-infrared Region, Where Many Important Chemical and Biological Species Have Strong Absorption Fingerprints March 21st, 2019

Fish-Inspired Material Changes Color Using Nanocolumns March 18th, 2019

New method to reduce uranium concentration in contaminated water March 18th, 2019

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

Gold nanoparticles to facilitate in-situ detection of amplified DNA at room temperature March 21st, 2019

Fish-Inspired Material Changes Color Using Nanocolumns March 18th, 2019

New method to reduce uranium concentration in contaminated water March 18th, 2019

Converting biomass by applying mechanical force Nanoscientists discover new mechanism to cleave cellulose effectively and in an environmentally friendly way March 15th, 2019

Quantum nanoscience

Quantum sensing method measures minuscule magnetic fields: MIT researchers find a new way to make nanoscale measurements of fields in more than one dimension March 15th, 2019

When semiconductors stick together, materials go quantum: A new study led by Berkeley Lab reveals how aligned layers of atomically thin semiconductors can yield an exotic new quantum material March 12th, 2019

A quantum magnet with a topological twist: Materials with a kagome lattice pattern exhibit 'negative magnetism' and long-sought 'flat-band' electrons February 23rd, 2019

NRL, AFRL develop direct-write quantum calligraphy in monolayer semiconductors February 15th, 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