Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Electrons and liquid helium advance understanding of zero-resistance: Study of electrons on liquid helium systems sheds light on zero-resistance phenomenon in semiconductors

This is a cell (container) where the electrons on liquid helium experiments are conducted.
CREDIT: OIST
This is a cell (container) where the electrons on liquid helium experiments are conducted.

CREDIT: OIST

Abstract:
The end of Moore's Law -- the prediction that transistor density would double every two years -- was one of the hottest topics in electronics-related discussions in 2015. Silicon-based technologies have nearly reached the physical limits of the number and size of transistors that can be crammed into one chip, but alternative technologies are still far from mass implementation. The amount of heat generated during operation and the sizes of atoms and molecules in materials used in transistor manufacturing are some of problems that need to be solved for Moore's Law to make a comeback.

Electrons and liquid helium advance understanding of zero-resistance: Study of electrons on liquid helium systems sheds light on zero-resistance phenomenon in semiconductors

Okinawa, Japan | Posted on February 2nd, 2016

Atomic and molecular sizes cannot be changed, but the heat problem is not unsolvable. Recent research has shown that in two-dimensional systems, including semiconductors, electrical resistance decreases and can reach almost zero when they are subjected to magnetic and microwave influence. Electrical resistance produces a loss of energy in the form of heat; therefore, a decrease in resistance reduces heat generation. There are several different models and explanations for the zero-resistance phenomenon in these systems. however, the scientific community has not reached an agreement on this matter because semiconductors used in electronics are complex and processes in them are difficult to model mathematically.

Research conducted by the Quantum Dynamics Unit at Okinawa Institute of Science and Technology graduate University (OIST) could represent an important step in understanding two-dimensional semiconductors. The Unit's latest paper, published in Physical Review Letters, describes anomalies in the behaviour of electrons in electrons on liquid helium two-dimensional system.

The system is maintained at a temperature close to absolute zero (-272.75ºC or 0.4K) to keep the helium liquefied. Extraneous electrons are bound to the helium surface because their presence causes slight changes in the orbits of helium electrons, inducing a subtle positive charge at the helium surface. At the same time, free electrons lack the energy required to penetrate the surface to enter the liquid. The resulting system is ideal for studying various electron properties, as it has virtually zero impurities, which avoids artefacts caused by defects of surface and structure, or due to the presence of other chemical elements. Prof. Denis Konstantinov, head of the Quantum Dynamics Unit, and his team study conditions under which electrons can violate selection rules regulating transitions from one state to another.

In a macro-world we perceive transitions from one state to another as happening gradually. For example, a person travelling from town A to town B can make an infinite number of stops. In micro-world that is not always the case. Properties, such as energy, position, speed, and colour, can be quantised, i.e. they can occur only in discrete quantities. In other words, the traveller can be either in town A, or town B, but not somewhere in-between.

Since electron energy is quantised, electrons can occupy only specific energy levels. Quantum theory predicts that in a two-dimensional electron system, where moving electrons are confined to one plane, under a strong magnetic field electrons also will be restricted to climbing only one step of the energy level ladder at a time. however, the experiments show that electrons can jump to higher energy levels, skipping levels between. Prof. Konstantinov and his team are very excited about this discovery: "It is not everyday that we get a chance to observe the violation of quantum theory predictions!"

In order to study abnormalities in electron state changes, the scientists applied a strong vertical magnetic field and then bombarded the system with microwave photons. Under these conditions selection rules seem to stop working. Prof. Konstantinov says that his group had theorised that such a phenomenon is possible and now they have proven it.

Selection rules describe a theoretical, absolutely pure, and homogenous system with no disorders. Real-life systems are more complex. In the case of electrons on helium, the system is pure and homogenous, but the surface of liquid helium is nonetheless disturbed by capillary waves -- ripples associated with the surface tension and similar to small, circular ripples in a pond when a pebble is tossed into the water. The height of these ripples is only the diameter of a hydrogen atom, but in combination with microwave radiation they create enough deviation from an ideal system for selection rules to change.

Conditions modelled in the Quantum Dynamics Unit's experiment are similar to those that led to observations of zero resistance in semiconductors. however, the electrons on helium system is relatively simple and can be described mathematically with great precision. Studying this system will further the development of quantum physics and will contribute to our understanding of electrons and various electrical phenomena. moreover, with some adjustments models, based on electrons on helium systems can be adapted to more complex systems, such as two-dimensional semiconductors.

####

For more information, please click here

Contacts:
Kaoru Natori

81-989-662-389

Copyright © Okinawa Institute of Science and Technology Graduate Univers

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

Photonic chip guides single photons, even when there are bends in the road February 16th, 2018

Arrowhead Receives Regulatory Clearance to Begin Phase 1/2 Study of ARO-HBV for Treatment of Hepatitis B February 15th, 2018

Arrowhead Pharmaceuticals Receives Orphan Drug Designation for ARO-AAT February 15th, 2018

European & Korean Project To Demo World’s First 5G Platform During Winter Games February 15th, 2018

Quantum Physics

New silicon chip for helping build quantum computers and securing our information February 8th, 2018

Quantum cocktail provides insights on memory control: Experiments based on atoms in a shaken artificial crystal offer insight that might help in the development of future data-storage devices January 26th, 2018

New oxide and semiconductor combination builds new device potential: Researchers integrated oxide two-dimensional electron gases with gallium arsenide and paved the way toward new opto-electrical devices January 10th, 2018

Physics

Liquid crystal molecules form nano rings: Quantized self-assembly enables design of materials with novel properties February 7th, 2018

New exotic phenomena seen in photonic crystals: Researchers observe, for the first time, topological effects unique to an “open” system January 12th, 2018

Chip Technology

Photonic chip guides single photons, even when there are bends in the road February 16th, 2018

Graphene on toast, anyone? Rice University scientists create patterned graphene onto food, paper, cloth, cardboard February 13th, 2018

Liquid crystal molecules form nano rings: Quantized self-assembly enables design of materials with novel properties February 7th, 2018

Nanometrics Selected for Fab-Wide Process Control Metrology by Domestic China 3D-NAND Manufacturer: Latest Fab Win Includes Comprehensive Suite for Substrate, Thin Film and Critical Dimension Metrology February 7th, 2018

Discoveries

Photonic chip guides single photons, even when there are bends in the road February 16th, 2018

'Living bandages': NUST MISIS scientists develop biocompatible anti-burn nanofibers February 15th, 2018

Rutgers-Led Innovation Could Spur Faster, Cheaper, Nano-Based Manufacturing: Scalable and cost-effective manufacturing of thin film devices February 14th, 2018

Understanding brain functions using upconversion nanoparticles: Researchers can now send light deep into the brain to study neural activities February 14th, 2018

Announcements

Photonic chip guides single photons, even when there are bends in the road February 16th, 2018

Arrowhead Receives Regulatory Clearance to Begin Phase 1/2 Study of ARO-HBV for Treatment of Hepatitis B February 15th, 2018

Arrowhead Pharmaceuticals Receives Orphan Drug Designation for ARO-AAT February 15th, 2018

European & Korean Project To Demo World’s First 5G Platform During Winter Games February 15th, 2018

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

Photonic chip guides single photons, even when there are bends in the road February 16th, 2018

'Living bandages': NUST MISIS scientists develop biocompatible anti-burn nanofibers February 15th, 2018

Rutgers-Led Innovation Could Spur Faster, Cheaper, Nano-Based Manufacturing: Scalable and cost-effective manufacturing of thin film devices February 14th, 2018

Understanding brain functions using upconversion nanoparticles: Researchers can now send light deep into the brain to study neural activities February 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
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project