Under the Sun!

Under the Sun!

I hope you’re all enjoying your summer! Incoming Prefrosh, I remember that my Prefrosh summer was amazing! However, I’m not at all implying that my Techer summer is any less amazing.

I promised last time that I’d talk a bit about by SURF project. I’m in an Experimental Physics condensed matter lab run by Professor Eisenstein. The Professor is my official mentor and I have a graduate student co-mentor assigned to me (this is the case with all SURF students). A focus of this lab is to study the electrical transport behavior in materials - specifically in graphite and graphene - under certain conditions. The samples must be quite small. I’m working with graphite this summer, finding samples, identifying the better ones and then processing them on silicon chip substrates to create gold electrodes that attach to the graphite. These electrodes allow me to make electrical transport measurements on the graphite by passing currents across the graphite. Some measurements require very low temperatures of about 4 degrees Kelvin and magnetic fields of about 14 Teslas! One funny thing about my project is the balance of low-tech and high-tech. To create the electrodes I first design them on design-cad software. I then use the Scanning Electron Microscope to actually create the design on my sample. I then use a thermal evaporator to deposit gold over the sample (“deposition”) and then I remove excess gold - where I don’t want a pattern - with acetone (“lift-off”). For the lower-tech aspect, I then solder by hand under a microscope - the riskiest part of my process - to attach tiny gold wires to the freshly-created electrodes that are roughly 300-500 microns wide. For the lowest-tech aspect, I use the “scotch tape exfoliation method” to get graphite samples in the first place! This method works surprisingly well for its simplicity. I start by placing a graphite flake on the sticky side of a piece of scotch tape. Then I fold the scotch tape onto itself and peel it apart which peels the graphite apart. This I repeat many times until I get a small enough piece of graphite which I then place on a silicon chip substrate. Here are some images to give you a clearer idea:

In the center is a good sample of graphite ready to be processed.

Here is a zoom-ed in image of the graphite piece with the gold electrodes leading up to it. Each wire is 1-2 microns wide at the place where it makes contact with the graphite.

Creating working samples is hard enough but next comes the actual measurement process. I hope to get a clear resistance measurement of graphite and to understand as much of the interesting physics as possible.

Outside the lab I’ve been having a pretty awesome summer. First of all, we’re in California. Second, it is summer. The two go very well together and I’ve been trying to take advantage of this! Last weekend I went home to visit my parents for my Mom’s birthday (Happy Birthday, Mom!). I haven’t been home for 16 weeks! Four months! I didn’t think that would ever be possible! Fortunately most of the time I’ve been busy enough on campus not to think of how long it’s been. However, no matter what you’re thinking now about never being homesick once you get to college (I know some of you are thinking this!), homesickness will hit you hard sooner or later. It may take just a single day when you realize that you have to do your own laundry, it may take a whole Term or even a couple of years but it will hit you. Fortunately my parents have visited me in Pasadena several times throughout those four months so the stretch wasn’t too terrible. Moral of the story: appreciate home while you’re a constant inhabitant and make your “homemates” know this.

Anyways, those two days were quite packed and I got back to Caltech feeling like I’ve been gone for a week. I flew back Friday evening - a one-hour flight from Pasadena to Oakland/Bay Area/San Francisco. There are two airports close to Caltech (Burbank and LAX and Supershuttle has three registered stops that are right on campus.

On the plane, there were at least six lawyers and at least six of them were corporate lawyers, and I sat between four of them - two on each side. Two were on the same case for a rather big company (no names) but one was defending, the other accusing and it was quite amusing to observe the dynamic between them. They’ve been traveling together for a while know because of this case and they’ve gotten to know each other pretty well.

When I got home, it was great to see my parents again and to see my house! A few days earlier my Mom asked me if I had any food requests and I immediately said Egg Benedict. Saturday morning, here’s what I woke up to:

I enjoyed the first half of the day at home but then we went to San Fransisco to an Impressionist exhibit visiting form the Musee d’Orsay in Paris. Then we had dinner with my Mom’s High School Physics teacher and her husband.

The couple we had dinner with is pretty interesting. My Mom’s science High School is in St. Petersburg, Russia and her Physics teacher is still teaching at that same school in St. Petersburg. Since a lot of her former students are now in the US as well as her children, she and her husband visit the USA every summer and see their children, a close friend and some of the wife’s former students! Here we are:

On Sunday my parents and I drove down to Monterey for the day:

Monday morning I flew back right into Lab and on my ride from the airport I met a Caltech alum doing graduate research here for the summer.

This Friday I’m participating in a Current Student Panel for the Caltech Preview Weekend. The last time I did this one prospective student sitting in the front row recognized another panelist Mario and me as bloggers so as Mario has already done, here’s to Jeff!

Cheers, Nina.