Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Electronics based on a 2-D electron gas: A new material could open the door to a new kind of electronics: researchers at the Vienna University of Technology have created a stable two-dimensional electron gas in strontium titanate

This shows the atomic structure of SrTiO3(110).

Credit: TU Vienna
This shows the atomic structure of SrTiO3(110).

Credit: TU Vienna

Abstract:
Usually, microelectronic devices are made of silicon or similar semiconductors. Recently, the electronic properties of metal oxides have become quite interesting. These materials are more complex, yet offer a broader range of possibilities to tune their properties. An important breakthrough has now been achieved at the Vienna University of Technology: a two dimensional electron gas was created in strontium titanate. In a thin layer just below the surface electrons can move freely and occupy different quantum states.

Electronics based on a 2-D electron gas: A new material could open the door to a new kind of electronics: researchers at the Vienna University of Technology have created a stable two-dimensional electron gas in strontium titanate

Vienna, Austria | Posted on March 3rd, 2014

Strontium titanate is not only a potential future alternative to standard semiconductors, it could also exhibit interesting phenomena, such as superconductivity, thermoelectricity or magnetic effects that do not occur in the materials that are used for today's electronic devices.

The Surface Layer and the Inside

This project closely links theoretical calculations and experiments. Zhiming Wang from Professor Ulrike Diebold's research team was the leading experimentalist; some of the experimental work was done at the synchrotron BESSY in Berlin. Zhicheng Zhong from Professor Karsten Held's group studied the material in computer simulations.

Not all of the atoms of strontium titanate are arranged in the same pattern: if the material is cut at a certain angle, the atoms of the surface layer form a structure, which is different from the structure in the bulk of the material. "Inside, every titanium atom has six neighbouring oxygen atoms, whereas the titanium atoms at the surface are only connected to four oxygen atoms each", says Ulrike Diebold. This is the reason for the remarkable chemical stability of the surface. Normally such materials are damaged if they come into contact with water or oxygen.

Migrating Oxygen Atoms

Something remarkable happens when the material is irradiated with high-energy electromagnetic waves: "The radiation can remove oxygen atoms from the surface", Ulrike Diebold explains. Then other oxygen atoms from within the bulk of the material move up to the surface. Inside the material, an oxygen deficiency builds up, as well a surplus of electrons.

"These electrons, located in a two dimensional layer very close to the surface, can move freely. We call this an electron gas", says Karsten Held. There has already been some evidence of two dimensional electron gases in similar materials, but until now the creation of a stable, durable electron gas at a surface has been impossible. The properties of the electrons in the gas can be finely tuned. Depending on the intensity of the radiation, the number of electrons varies. By adding different atoms, the electronic properties can also be changed.

"In solid state physics, the so-called band structure of a material is very important. It describes the relationship between the energy and the momentum of the electrons. The remarkable thing about our surface is that it shows completely different kinds of band structures, depending on the quantum state of the electron", says Karsten Held.

The electron gas in the new material exhibits a multitude of different electronic structures. Some of them could very well be suitable for producing interesting magnetic effects or superconductivity. The promising properties of strontium titanate will now be further investigated. The researchers hope that, by applying external electric fields or by placing additional metal atoms on the surface, the new material could reveal a few more of its secrets.

####

For more information, please click here

Contacts:
Prof. Ulrike Diebold
Institute for Applied Physics
Vienna University of Technology
Wiedner Hauptstraße 8-10, 1040 Wien
+43-1- 58801-13425


Prof. Karsten Held
Institut for Solid State Physics
Vienna University of Technology
Wiedner Hauptstraße 8
T: +43-1-58801-13710


Florian Aigner

43-158-801-41027
Vienna University of Technology

Copyright © Vienna University of Technology

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

Switching with molecules: Molecular switch will facilitate the development of pioneering electro-optical devices May 25th, 2018

Tunable diamond string may hold key to quantum memory: A process similar to guitar tuning improves storage time of quantum memory May 24th, 2018

Remote control of transport through nanopores: New study outlines key factors affecting the transfer of molecules through biological channels May 24th, 2018

2018 Kavli Prizes in Astrophysics, Nanoscience, and Neuroscience to be Announced Live on May 31: Live announcement at the Norwegian Academy of Science and Letters to be streamed live at World Science Festival Event May 24th, 2018

Superconductivity

Scientists Pinpoint Energy Flowing Through Vibrations in Superconducting Crystals: Interactions between electrons and the atomic structure of high-temperature superconductors impacted by elusive and powerful vibrations May 4th, 2018

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 April 16th, 2018

Superconductivity in an alloy with quasicrystal structure March 27th, 2018

Piezomagnetic material changes magnetic properties when stretched March 22nd, 2018

Chip Technology

Switching with molecules: Molecular switch will facilitate the development of pioneering electro-optical devices May 25th, 2018

Columbia Researchers Squeeze Light into Nanoscale Devices and Circuits: Team is first to directly image propagation and dynamics of graphene plasmons at very low temperatures; findings could impact optical communications and signal processing May 23rd, 2018

Supersonic waves may help electronics beat the heat May 18th, 2018

Deeper understanding of quantum chaos may be the key to quantum computers May 16th, 2018

Discoveries

Switching with molecules: Molecular switch will facilitate the development of pioneering electro-optical devices May 25th, 2018

Tunable diamond string may hold key to quantum memory: A process similar to guitar tuning improves storage time of quantum memory May 24th, 2018

Remote control of transport through nanopores: New study outlines key factors affecting the transfer of molecules through biological channels May 24th, 2018

'Spooky action at a distance': Researchers develop module for quantum repeater May 23rd, 2018

Announcements

Switching with molecules: Molecular switch will facilitate the development of pioneering electro-optical devices May 25th, 2018

Tunable diamond string may hold key to quantum memory: A process similar to guitar tuning improves storage time of quantum memory May 24th, 2018

Remote control of transport through nanopores: New study outlines key factors affecting the transfer of molecules through biological channels May 24th, 2018

2018 Kavli Prizes in Astrophysics, Nanoscience, and Neuroscience to be Announced Live on May 31: Live announcement at the Norwegian Academy of Science and Letters to be streamed live at World Science Festival Event May 24th, 2018

Quantum nanoscience

Nanoscale measurements 100x more precise, thanks to improved two-photon technique May 8th, 2018

'Exceptional' research points way toward quantum discoveries: Rice University scientists make tunable light-matter couplings in nanotube films April 30th, 2018

New qubit now works without breaks: A universal design for superconducting qubits has been created April 19th, 2018

Quantum shift shows itself in coupled light and matter: Rice University scientists corral, quantify subtle movement in condensed matter system April 16th, 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