Eric Spanton, Moler Group
Imaging transport current using scanning SQUID microscopy
We use a scanning superconducting quantum interference device (SQUID) to investigate magnetic phenomena on a micron scale. By locally imaging magnetic fields due to current flowing through a sample, we are able to reconstruct a local 2D current density. I will highlight applications of this technique to two different physical systems. First, I will present images of current through two different quantum spin hall systems (HgTe and InAs/GaSb quantum wells), showing edge currents when the devices are tuned into their respective gaps using a top gate. Secondly, I will show images of current through LAO/STO which show an unexpected high conduction along twin boundaries.