poster about atomic nanolines
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Drawn freely with
1D templates for atomic chains on Si(001) Universit de Genve, DPMC Department of Physics & Astronomy, UCL and LCN, London
1 1 11 1 2F. Bianco, J. Owen, S. Kster, D. Mazur, D. Bowler and C. Renner1
Haiku stripe
PropertiesBismuth nanolineMotivations
5 57 5 7
Haiku structure
Composed of 5- and 7- foldrings of SiA Haiku ( ) is a Japanesepoem with 5-7-5 syllables
Exactly 4 Si dimers wide (15.4 )
Extends 5 layers below the surface
Double row of Bi dimersperpendicular to Si dimers
Review article : J. Mat. Sci 41 (14) 4568 (2006)
Probe 1D physics experimentally
Provide new way of growingatomic chains
Alternative to vincinal surfaces
Interconnects for novel electronics
Allow the growth of 1D structuresindependent of step edges
Perfectly straight, no kinks
Can exceed 1m in length
Self-assembled structure withvery few defects
Stable up to 500C in UHV
Adsorption of metal alongor in between the Bi dimers
Matches DFT simulation very well
State in the middle of structureseen in empty states imagingMany favorable sites for metaladsorption predicted by computation
Best explained by removingBi from Haiku structureRHEED shows an arc from a 1Dstructure, no more Bi peaks in XPS
V = -3.0 V, I = 250 pA, T = 77 K V = -3.0 V, I = 250 pA, T = 77 K
*
old pond...a frog leaps inwaters sound *
Bi dimers are stripped by H
Forms by exposing Bi nanolinesto hydrogen
Si monohydride surface passive inair, therefore likely to be stable in air
Same structural properties asthe Haiku core of Bi nanoline
Provide direct observation ofthe Haiku structure
Novel Si-only template, withoutany defects
Stable up to 400C in UHV
Surface analysis
After Bi deposition
After H deposition
Binding energy
Coun
ts/s
Bi
Bi
SiSi
After HBefore H
Bi
XPS RHEED
Side view
Outlook
Determine transport propertiesof the templatesDope the Haiku stripes chemicallyor electrostatically
Characterise templating properties
Look for metallic properties
Expose sample to air to conrmstability
Haiku core structure
- 0.3 V
Filled statesV = -2.9 V, I = 150 pA, T = 77 KV = - 2.5 V, I = 100 pA, T = 77 K
Empty states
+ 1.8 V
+ 2.0 V
+ 2.5 V
I = 150 pA, T = 77 K V = +2.0 V, I = 150 pA, T = 77 K
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