Condensed Matter Physics Seminar

Professor Yoonseok Lee, University of Florida

Friday 11 April 2014, 1500-1600
C1 Physics Building

MEMS-based Probe for the Study of Quantum Fluids

One of the most distinct properties of unconventional superfluids/superconductors is the extreme fragility of Cooper pairs against any types of impurity or disorder. The surface scattering in these systems readily breaks Cooper pairs and consequently induces quasi-particle bound states near the surface within the coherence length, often called Andreev surface bound states. This generic nature of the unconventional order parameter near the boundaries becomes prominent in a film. This property combined with the exotic symmetries in the superfluid phases of helium-3 with p-wave spin triplet pairing is at the heart of many fascinating phenomena in confined geometry. We have developed a Micro-Electro-Mechanical System (MEMS) based probe to study thin films of superfluid helium-3. Using a commercial micro-machining process, MEMS oscillators were designed, manufactured, and characterized. We will discuss the design and the operation of the device, and will present results obtained using these devices in air, liquid helium-3 and also in liquid helium-4 in a wide range of temperature down to sub-millikelvin range.