Spin-Polarized
Scanning Tunneling Microscopy

Researchers

Liz Main, Adam Pivonka, Ilija Zeljkovic

Instrument

• Simple explanation of STM (no equations)
• Technical explanation of STM
• Measurements we can make with an STM
• Explanation of Spin-Polarized STM

We have constructed a custom variable temperature scanning tunneling microscope with the following features optimized for spin-polarized tunneling:

• Vibration isolation: floating room, floating table,
  internal suspension from magnetically damped springs.
• Temperature: 2K up to 300K
• Magnetic field: 9 Tesla vertical, 3 Tesla horizontal
• Scan Range: 1μm scan at room temperature;
  several mm coarse (x,y,z) motion of sample with respect to tip
• Tip/sample: in-situ tip/sample exchange, tip/sample cold storage carousel
• Surface prep: cold cleaver, in-situ evaporator

STM body

Flow Cryostat

Vacuum Chamber

Scientific Results

We are investigating the cuprate high-T_c superconductor Bi₂Sr₂CaCu₂O_8+x. This topographic image was acquired at 4 Kelvin.

Funding

NSF CAREER DMR-0847433, AFOSR PECASE FA9550-06-1-0531, AFOSR DURIP FA9550-06-1-0359