Featured Research

from universities, journals, and other organizations

Letting The Spin Loose

Date:
July 13, 2005
Source:
Weizmann Institute of Science
Summary:
Two properties of an electron - its spin and its charge - are generally thought to be inseparable, intrinsic characteristics, no more given to sudden changes or going off on their own than say, the fur on a cat or the paint on a bicycle.

Two properties of an electron - its spin and its charge - are generally thought to be inseparable, intrinsic characteristics, no more given to sudden changes or going off on their own than say, the fur on a cat or the paint on a bicycle. But a team of scientists at the Weizmann Institute of Science has recently demonstrated conclusively that, in very specific circumstances, spin can become separated from charge and progress independently down a wire. Their findings appeared in a recent issue of Science.

Spin-charge separation was first predicted in the sixties. The idea was based on a theory that electrons with a range of movement limited to one dimension alone would behave differently from those moving in two or three dimensions. This is because when electrons are lined up head to tail, the influence of the repulsive forces between them becomes overridingly significant. But demonstrating the phenomenon had to wait until technology caught up to the theory.

Prof. Amir Yacoby of the Institute's Condensed Matter Physics Department and research students Dr. Ophir Auslaender and Hadar Steinberg set up an experiment with quantum wires - so thin that electrons must go single file down their length, limiting flow to a single dimension and direction. "Up to a certain point, one can think of these electrons as cars on a narrow, one lane road: there's no passing, and the slowest car sets the speed for the rest. A block in the road will bring all traffic to a halt. But here the analogy ends. If you increase car density on a road, traffic invariably slows down, while electrons speed along merrily in high-density flow and slow down when the density decreases. It is in these slow-moving, low density electron flows that things become interesting."

The separation the team achieved between spin and charge rests on the fact that the spins of electrons in these low density, single dimension flows generally follow a preferred arrangement: alternating between the two possible directions of electron spin - up and down. In the experiment, single electrons here and there could jump from wire to wire, allowing the scientists to jumble traffic a bit. So when an electron in the middle having, say, a down spin stepped out of the line, the next electron moved up to fill in, creating a situation with two neighboring ups. This non-ideal state of affairs caused one of them to flip its spin to down, which then caused the next electron, also with a down spin, to flip its spin to up, and so on. Thus the spin traveled down the wire independently of the charge, which stayed tied to the electrons.

###

Prof. Amir Yacoby's research is funded by the Rosa and Emilio Segre Fund; and the Joseph H. and Belle R. Braun Center for Submicron Research.


Story Source:

The above story is based on materials provided by Weizmann Institute of Science. Note: Materials may be edited for content and length.


Cite This Page:

Weizmann Institute of Science. "Letting The Spin Loose." ScienceDaily. ScienceDaily, 13 July 2005. <www.sciencedaily.com/releases/2005/07/050712230449.htm>.
Weizmann Institute of Science. (2005, July 13). Letting The Spin Loose. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2005/07/050712230449.htm
Weizmann Institute of Science. "Letting The Spin Loose." ScienceDaily. www.sciencedaily.com/releases/2005/07/050712230449.htm (accessed July 24, 2014).

Share This




More Matter & Energy News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Creative Makeovers for Ugly Cellphone Towers

Creative Makeovers for Ugly Cellphone Towers

AP (July 24, 2014) — Mobile phone companies and communities across the country are going to new lengths to disguise those unsightly cellphone towers. From a church bell tower to a flagpole, even a pencil, some towers are trying to make a point. (July 24) Video provided by AP
Powered by NewsLook.com
Algonquin Power Goes Activist on Its Target Gas Natural

Algonquin Power Goes Activist on Its Target Gas Natural

TheStreet (July 23, 2014) — When The Deal's Amanda Levin exclusively reported that Gas Natural had been talking to potential suitors, the Ohio company responded with a flat denial, claiming its board had not talked to anyone about a possible sale. Lo and behold, Canadian utility Algonquin Power and Utilities not only had approached the company, but it did it three times. Its last offer was for $13 per share as Gas Natural's was trading at a 60-day moving average of about $12.50 per share. Now Algonquin, which has a 4.9% stake in Gas Natural, has taken its case to shareholders, calling on them to back its proposals or, possibly, a change in the target's board. Video provided by TheStreet
Powered by NewsLook.com
Robot Parking Valet Creates Stress-Free Travel

Robot Parking Valet Creates Stress-Free Travel

AP (July 23, 2014) — 'Ray' the robotic parking valet at Dusseldorf Airport in Germany lets travelers to avoid the hassle of finding a parking spot before heading to the check-in desk. (July 23) Video provided by AP
Powered by NewsLook.com
Boeing Ups Outlook on 52% Profit Jump

Boeing Ups Outlook on 52% Profit Jump

Reuters - Business Video Online (July 23, 2014) — Commercial aircraft deliveries rose seven percent at Boeing, prompting the aerospace company to boost full-year profit guidance- though quarterly revenues missed analyst estimates. Bobbi Rebell reports. Video provided by Reuters
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