Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


New Nanoscale Device Reveals Behavior of Individual Electrons


Laptop computers can generate enough heat that, in rare cases, they actually catch fire. While engineers have a great grasp of how to control electrical charge in circuits, they have a hard time getting rid of the heat created by flowing electrons. What’s missing is a fundamental understanding of how individual electrons generate heat.

A new device developed by University of Wisconsin-Madison Electrical and Computer Engineering Associate Professor Robert Blick promises to change that. In addition, it will provide insights into harnessing quantum forces for communication and computing.

Blick, along with his graduate student Eva Hoehberger and colleague Werner Wegscheider, developed something similar to an incredibly small trampoline for bouncing individual electrons. It operates as an artificial atom, or a membrane, suspended over a semiconductor cavity.

Featured on the cover of the June 9 issue of Applied Physics Letters, the tool will allow researchers to study for the first time, in detail, the influence of heat dissipation on single electron transport in these transistors.

The device, just 100 nanometers wide or about one ten-millionth of an inch, looks and acts, in a way, like a really small guitar. A conventional guitar string vibrates at several thousand cycles per second, but if you reduced the size to several hundred nanometers, the string would vibrate at speeds in the gigahertz regime, or around a billion cycles per second.

On that scale, the movement in the string, or suspended membrane in the case of this new device, is incredibly small. Blick says the effects of heat dissipation will show up as vibrations of the suspended artificial atoms. This motion causes a change in voltage that researchers can measure.

"Our system is comprised with many gates so that we can study the full variety of electronic systems starting with two-dimensional electron flows, which is common in many transistors these days," Blick says. "We can then reduce that to a channel where electrons flow in only one dimension like a string of electrons, and finally we can tune the device to a zero-dimensional state, which is the so-called single-electron transistor. We can bounce around single electrons, very controlled, and see how they spread energy in these very thin membranes."

Blick says understanding energy transfer at these levels offers very practical, near-term benefits for chip manufacturers. The device itself is constructed of semiconductor materials and, at 100 nanometers, its size and fabrication represent the future of the industry. Lessons learned from this tool could allow engineers to optimize existing technology currently limited by heat dissipation.

In the longer term, the tool could reveal important secrets that allow researchers to exploit the power of quantum computing and communication.

In a conventional computer, the presence of a group of electrons shows up as a negative charge and represents the "zero state" in binary logic, called a bit. When that charge is missing, the "one state" is represented. But a quantum computer deals with the quantum mechanics of electrons, which can be used to define so-called quantum bits or qubits. Unlike bits, these qubits can exist in more than one state at once. This frees quantum computers to calculate all the possible solutions to a complex problem simultaneously, rather than running through them one-by-one like their slower, serial counterparts.

Key to developing a practical quantum computer, however, involves understanding exactly what represents information and how to get it out of the device.

Blick’s system, when tuned to the zero-dimension state, will add to this understanding - it will allow researchers to observe an individual electron near the qubit level as it approaches what’s known as the Heisenberg uncertainty principle. This law of nature holds that as soon as you try to exactly determine the whereabouts of a quantum mechanical particle, you can no longer be certain of where it is going, since any action to measure the particle changes the particle’s condition.

"An electron spread out as a wave, as a fermionic particle, has a scale of some five nanometers and this is exactly what we can address with our device." Blick says. "We can study information processing on the quantum level and see whether the Heisenberg principle gives us a real obstacle, or whether we can find ways around it by using quantum-nondemolition techniques."

Robert Blick | University of Wisconsin
Further information:

All articles from Information Technology >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

New method increases energy density in lithium batteries

24.10.2016 | Power and Electrical Engineering

International team discovers novel Alzheimer's disease risk gene among Icelanders

24.10.2016 | Life Sciences

New bacteria groups, and stunning diversity, discovered underground

24.10.2016 | Life Sciences

More VideoLinks >>>