Featured Research

from universities, journals, and other organizations

When nanotechnology meets quantum physics in one dimension: New experiment supports long-predicted 'Luttinger liquid' model

Date:
January 23, 2014
Source:
McGill University
Summary:
Scientists have succeeded in conducting a new experiment that supports the existence of the long-sought-after Luttinger liquid state.

How would electrons behave if confined to a wire so slender they could pass through it only in single-file?

The question has intrigued scientists for more than half a century. In 1950, Japanese Nobel Prize winner Sin-Itiro Tomonaga, followed by American physicist Joaquin Mazdak Luttinger in 1963, came up with a mathematical model showing that the effects of one particle on all others in a one-dimensional line would be much greater than in two- or three-dimensional spaces. Among quantum physicists, this model came to be known as the "Luttinger liquid" state.

Until very recently, however, there had been only a few successful attempts to test the model in devices similar to those in computers, because of the engineering complexity involved. Now, scientists from McGill University and Sandia National Laboratories have succeeded in conducting a new experiment that supports the existence of the long-sought-after Luttinger liquid state. Their findings, published in the Jan. 23 issue of Science Express, validate important predictions of the Luttinger liquid model.

The experiment was led by McGill PhD student Dominique Laroche under the supervision of Professor Guillaume Gervais of McGill's Department of Physics and Dr. Michael Lilly of Sandia National Laboratories in Albuquerque, N.M. The new study follows on the team's discovery in 2011 of a way to engineer one of the world's smallest electronic circuits, formed by two wires separated by only about 15 nanometers, or roughly 150 atoms.

What does one-dimensional quantum physics involve? Gervais explains it this way: "Imagine that you are driving on a highway and the traffic is not too dense. If a car stops in front of you, you can get around it by passing to the left or right. That's two-dimensional physics. But if you enter a tunnel with a single lane and a car stops, all the other cars behind it must slam on the brakes. That's the essence of the Luttinger liquid effect. The way electrons behave in the Luttinger state is entirely different because they all become coupled to one another."

To scientists, "what is so fascinating and elegant about quantum physics in one dimension is that the solutions are mathematically exact," Gervais adds. "In most other cases, the solutions are only approximate."

Making a device with the correct parameters to conduct the experiment was no simple task, however, despite the team's 2011 discovery of a way to do so. It took years of trial, and more than 250 faulty devices -- each of which required 29 processing steps -- before Laroche's painstaking efforts succeeded in producing functional devices yielding reliable data. "So many things could go wrong during the fabrication process that troubleshooting the failed devices felt like educated guesswork at times," explains Laroche. "Adding in the inherent failure rate compounded at each processing step made the fabrication of these devices extremely challenging."

In particular, the experiment measures the effect that a very small electrical current in one of the wires has on a nearby wire. This can be viewed as the "friction" between the two circuits, and the experiment shows that this friction increases as the circuits are cooled to extremely low temperatures. This effect is a strong prediction of Luttinger liquid theory.

The experiments were conducted both at McGill University and at the Center for Integrated Nanotechnologies, a U.S. Department of Energy, Office of Basic Energy Sciences user facility operated by Sandia National Laboratories.

"It took a very long time to make these devices," said Lilly. "It's not impossible to do in other labs, but Sandia has crystal-growing capabilities, a microfabrication facility, and support for fundamental research from DOE's office of Basic Energy Sciences (BES), and we're very interested in understanding the fundamental ideas that drive the behavior of very small systems."

The findings could lead to practical applications in electronics and other fields. While it's difficult at this stage to predict what those might be, "the same was true in the case of the laser when it was invented," Gervais notes. "Nanotechnologies are already helping us in medicine, electronics and engineering -- and this work shows that they can help us get to the bottom of a long-standing question in quantum physics."

The research was supported by the Division of Materials Sciences and Engineering, Office of Basic Energy Sciences, U.S. Department of Energy; the Natural Sciences and Engineering Research Council of Canada (NSERC); the Canadian Institute for Advanced Research (CIFAR), and the Fonds qu้b้cois de la recherche sur la nature et les technologies (FQRNT).


Story Source:

The above story is based on materials provided by McGill University. Note: Materials may be edited for content and length.


Journal Reference:

  1. D. Laroche, G. Gervais, M. P. Lilly, and J. L. Reno. 1D-1D Coulomb Drag Signature of a Luttinger Liquid. Science, 23 January 2014 DOI: 10.1126/science.1244152

Cite This Page:

McGill University. "When nanotechnology meets quantum physics in one dimension: New experiment supports long-predicted 'Luttinger liquid' model." ScienceDaily. ScienceDaily, 23 January 2014. <www.sciencedaily.com/releases/2014/01/140123141715.htm>.
McGill University. (2014, January 23). When nanotechnology meets quantum physics in one dimension: New experiment supports long-predicted 'Luttinger liquid' model. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2014/01/140123141715.htm
McGill University. "When nanotechnology meets quantum physics in one dimension: New experiment supports long-predicted 'Luttinger liquid' model." ScienceDaily. www.sciencedaily.com/releases/2014/01/140123141715.htm (accessed April 23, 2014).

Share This



More Matter & Energy News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Is North Korea Planning Nuclear Test #4?

Is North Korea Planning Nuclear Test #4?

Newsy (Apr. 22, 2014) — South Korean officials say North Korea is preparing to conduct another nuclear test, but is Pyongyang just bluffing this time? Video provided by Newsy
Powered by NewsLook.com
China Falls for 4x4s at Beijing Auto Show

China Falls for 4x4s at Beijing Auto Show

AFP (Apr. 22, 2014) — The urban 4x4 is the latest must-have for Chinese drivers, whose conversion to the cult of the SUV is the talking point of this year's Beijing auto show. Duration: 00:40 Video provided by AFP
Powered by NewsLook.com
Lytro Introduces 'Illum,' A Professional Light-Field Camera

Lytro Introduces 'Illum,' A Professional Light-Field Camera

Newsy (Apr. 22, 2014) — The light-field photography engineers at Lytro unveiled their next innovation: a professional DSLR-like camera called "Illum." Video provided by Newsy
Powered by NewsLook.com
3 Reasons Why Harley Davidson Is Selling Tons of Epic Hogs

3 Reasons Why Harley Davidson Is Selling Tons of Epic Hogs

TheStreet (Apr. 22, 2014) — Sales of motorcycles have continued to ride back from the depths of hell known as the Great Recession. Excluding scooters, sales of motorcycles increased 3% in 2013. In units, however, at 465,000 sold last year, the total remained about 50% below the peak hit in 2007. Industry leader Harley Davidson’s shareholders have benefited both by the industry recovery and positive headlines emanating from the company. Belus Capital Advisors CEO Brian Sozzi takes you beyond the headlines of the motorcycle maker. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins