Electron density waves in a quantum corral.

Treefrog · 23-07-2009, 22:59

From here

I saw this on the cover of a book at a friend's house the other day and, when she explained what it was I was just blown away!

Using a Scanning Tunneling electron Microscope (STM) scientists arranged 48 Iron atoms in a circular corral on the surface of a piece of copper. Because copper is such a good electrical conductor there are a number of 'free' electrons on the surface and they stay inside the corral due to the charge of the Iron atoms' electron clouds.
The height of the waves inside the corral represents the chance of an electron being in that place, and as electrons behave (in part) like waves, they are 'reflected' from the corral walls in the same way that ripples from a stone dropped into a pond will bounce back when they reach the edge of the pond. What the photo shows is a ring approximately 13 atoms in diameter. A photograph of something that is thousands, if not millions, of times smaller than just one of the pixels you are currently looking at it on. Much, much smaller than the smallest grain of photographic emulsion that would previously have been used to record such a sight.

Another thought that occurred to me: if a normal everyday 6"x4" photograph were to be enlarged to the point where you could see individual atoms of the subject - how large would that photo then be?
The size of Europe? The Earth? The Earth's orbit? Our solar system?
And where do we go from here?

All I can say is: WOW!

Pickers · 23-07-2009, 23:12

It is really fascinating. My Nanophysics module at uni was just amazing to study... but pretty tricky when it came to the assessment

They've also made "nano writing" using the same technique - great stuff!

Fayshun · 24-07-2009, 07:38

Quote:

Originally Posted by Pickers

They've also made "nano writing" using the same technique - great stuff!

Didn't IBM make the worlds smallest smiley?

Del Lardo · 24-07-2009, 08:19

Quote:

Originally Posted by Treefrog

Another thought that occurred to me: if a normal everyday 6"x4" photograph were to be enlarged to the point where you could see individual atoms of the subject - how large would that photo then be?
The size of Europe? The Earth? The Earth's orbit? Our solar system?
And where do we go from here?

Rather tricky one to answer as atoms do not have a fixed size as they do not have a surface so very hard to measure. Also how do you define being able to see?

Assuming hydrogen atoms then you would be looking at ~1.5^18 atoms in the photo give or take a few trillion

Assuming you define seeing as each atom being 1mm then the photo would be ~10000miles wide and ~666miles tall.

I think..........

Will · 24-07-2009, 08:28

Gah this brings me back to uni days!!

Del Lardo · 24-07-2009, 08:30

Quote:

Originally Posted by Will

Gah this brings me back to uni days!!

You clearly paid far more attention than I did though that would explain why I failed

Fayshun · 24-07-2009, 08:39

Quote:

Originally Posted by Del Lardo

give or take a few trillion

Rounding error?

Will · 24-07-2009, 09:29

Quote:

Originally Posted by Del Lardo

You clearly paid far more attention than I did though that would explain why I failed

I kinda miss uni - but I dont' miss the lectures

Del Lardo · 24-07-2009, 15:32

I think I'd struggle to miss the lectures, spent far too much time doing that while I was there.

I've come to the conclusion that my massive intellect wasn't being challenged which is why I never went. Nothing to do with finding the course utterly dull and being drunk most of the time

Will · 24-07-2009, 15:39

Hehehe - funny thing is we hardly saw each others in lectures, it was usually on nights out!

Anyway that's a bit OT!

23-07-2009, 22:59	#1
Treefrog Survivor Join Date: Aug 2006 Location: Chell Heath, Stoke-on-Trent Posts: 1,761	Electron density waves in a quantum corral. From here I saw this on the cover of a book at a friend's house the other day and, when she explained what it was I was just blown away! Using a Scanning Tunneling electron Microscope (STM) scientists arranged 48 Iron atoms in a circular corral on the surface of a piece of copper. Because copper is such a good electrical conductor there are a number of 'free' electrons on the surface and they stay inside the corral due to the charge of the Iron atoms' electron clouds. The height of the waves inside the corral represents the chance of an electron being in that place, and as electrons behave (in part) like waves, they are 'reflected' from the corral walls in the same way that ripples from a stone dropped into a pond will bounce back when they reach the edge of the pond. What the photo shows is a ring approximately 13 atoms in diameter. A photograph of something that is thousands, if not millions, of times smaller than just one of the pixels you are currently looking at it on. Much, much smaller than the smallest grain of photographic emulsion that would previously have been used to record such a sight. Another thought that occurred to me: if a normal everyday 6"x4" photograph were to be enlarged to the point where you could see individual atoms of the subject - how large would that photo then be? The size of Europe? The Earth? The Earth's orbit? Our solar system? And where do we go from here? All I can say is: WOW! __________________ Commit random kindness and senseless acts of beauty

23-07-2009, 23:12	#2
Pickers Absinthe Join Date: Jul 2006 Location: Cornwall Posts: 2,692	It is really fascinating. My Nanophysics module at uni was just amazing to study... but pretty tricky when it came to the assessment They've also made "nano writing" using the same technique - great stuff! __________________ Pictures

24-07-2009, 08:28	#5
Will BBx woz 'ere :P Join Date: Jan 1970 Posts: 2,147,487,208	Gah this brings me back to uni days!! __________________ *No No!*

24-07-2009, 15:39	#10
Will BBx woz 'ere :P Join Date: Jan 1970 Posts: 2,147,487,208	Hehehe - funny thing is we hardly saw each others in lectures, it was usually on nights out! Anyway that's a bit OT! __________________ *No No!*

24-07-2009, 15:32	#9
Del Lardo Absinthe Join Date: Jan 2007 Location: Cambridge Posts: 2,539	I think I'd struggle to miss the lectures, spent far too much time doing that while I was there. I've come to the conclusion that my massive intellect wasn't being challenged which is why I never went. Nothing to do with finding the course utterly dull and being drunk most of the time