Wavefunction Imaging Scanning Tunneling Microscopy

1
Wavefunction Imaging Scanning Tunneling
Microscopy K. McElroy, J. Lee, J. E. Hoffman,
E.W. Hudson, K. M. Lang, J. C. Seamus Davis
Bi2Sr2CaCu2O8d
Local Density of Electronic States
0 256 Å
5.5 sq at 1.5, 2.75
91114I02
256 Å
0 256 Å
91119c01 10mV
At 10s per spectrum, a 5122 pixel array requires
2.5X106 s (1 month)
0 256 Å
STS Instrument Design
Ultra Low Vibration lab Design
Rev. Sci. Inst. 70, 1459 (1999).
Load Lock

• Massive LeadConcrete Cryostat
• STM High Field Magnet
• Sample Exchange from RT
• Cryogenic UHV Cleavage

Turbo Pump
to Pumps
Lead Filled Table
Air Springs
L4He
Fridge
Cleaver
Lead Legs
STM Head
Acoustic Bunker
High-field SC Magnet
Cuprate High-Tc Studies
Semiconductor Studies
CDW Studies
Ga(Te)As

1. Atomic resolution mK-STM
2. Local state tunneling spectroscopy
3. Spectroscopic mapping of Y2

NbSe2
Nanoscale e-disorder Vortex
Core-States Q. Interference
Impurity-States
For a dopant atom in GaAs (at Tlt20mK) we have
demonstrated .
128 Å
56 nm 0-12mV LDOS,B5T
64 nm 12 mV LDOS, B0
26 nm -9mV LDOS, B0
15 nm Gapmap, B0
Nature 414 282 (2002) Science 296 455
(2002) Science 297, 1148 (2002)
Nature 411, 920 (2001)

1. Atomic resolution mK-STM
2. Vortex core tunneling spectroscopy
3. Spectroscopic mapping of Y2 at Fe impurity atoms

Research Support