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Current work supported by DMR-1101189

Photo of Manuel

Manuel working on the dilution refrigerator

Manuel Diaz-Avila

Present Position:
Instructor, Department of Math, Physics, and Engineering
Mount Royal College
Calgary CA email: mdiazavila(at)

Ph.D in Physics
(University at Buffalo, 2006)

Work within the Lab

I completed studies of finite-size effects in films of 4He where the dimensionality crossover is from 2D to finite-size 2D.

To perform these studies, we constructed a cell with two regions of helium films connected by shallow and narrow channels. We use direct wafer bonding to combine two silicon wafers into a sealed cell.

Photo of Bottom wafer of the finite-size 2D cell

Here is one of the two patterned wafers that make a complete cell. The bright areas are silicon dioxide and the darker area is where the oxide has been lithographically removed exposing bare silicon. The height of the oxide area is 3000 angstroms. The outer oxide ring provides a leak-tight border for the cell. The inner ring separates the two film regions.

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Photo of shallow channel

This picture, created with an atomic force microscpe, shows the shallow channels which span the inner ring and connect the two film regions seen in the previous picture. These particular channels are 16 microns wide and 9.5 nm tall. Our technique to determine the superfluid fraction of the liquid in the cell involves moving helium between the two film regions.

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Recent Publications

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Last Updated: Tuesday, 11-May-2010 16:51:26 EDT by MOK