Grant: Research Tools and Instruments - Category 1 (<$150,000)

All electronic, magnetic and structural properties of a material are different near an interface between two materials.  In some cases these changes are subtle and confined to just a few atomic layers while in others the changes are dramatic and extend over many nanometres. In general a single interface (or series of interfaces in a multilayer) has its own distinct properties and phases which are of great technological significance. Giant magnetoresistance of magnetic multilayers is one notable example which lead to the 2007 Nobel Prize in Physics. Progress in understanding physics at interfaces is slow since few experimental methods are capable of probing local properties in a depth resolved manner. Recently the applicants have developed a novel technique of low energy beta-detected nuclear magnetic resonance for this purpose. The main idea is to use a variable low energy beam of highly spin-polarized radioactive nuclei such as 8Li to probe the local properties on a nm length scale. Since the nuclear polarization is detected through the asymmetric beta-decay of the probe nucleus, the technique is roughly ten orders of magnitude more sensitive than conventional NMR. We are requesting funds here for a pumped 3He cryostat to explore quantum phases of matter and their interfaces at temperatures down to  0.35 degrees above absolute zero.