Quantum Mechanic

Content from 2011-01

Hamilton in the Winter

posted on 2011-01-31 02:41:34

Winter in Hamilton is long - long enough that you can even notice distinct stages of it if you have to deal with it over and over again, as anyone who lives here does.  Now that it's almost February, we're entering the Slush Time.  That said, it still manages to be pretty beautiful sometimes, when you're not dealing with the wind blowing through the valley as you walk home through the slush that half melted earlier.

So, on the first day of classes (the 17th of January, this post is slightly out of order), I had the good foresight to take my camera along for the day, and since it was hideously cold everything was very clear and there were some interesting light-effects with snow in the air and whatnot.  There was a cloud hovering over the stream that runs through campus that you could walk through and not see people a few feet away.

My first droid

posted on 2011-01-24 02:52:06

I am typing this, somewhat slowly, on a new-to-me android smart phone. The typing is still rather slow, but not as painful as I had expected. Unfortunately, the delete button is right next to the "go to home screen button, which has already interrupted me once. That said, while typing this, I feel like I'm getting a lot faster. I also accidentally just quit this program and called my voicemail... It might be nice having it serve as an ogg player too. Now I just need to pray that I don't get totally sucked in and forget about people entirely!

Dawn of a New Semester

posted on 2011-01-13 06:48:47

It's now officially Thursday, which means there are only 3 more days before the new semester starts.  If all goes according to plan, I'll be taking Intro to Quantum, a class on teaching math, and a German theatre/plays course.  My fourth course slot will be filled by independent research, because I got asked if I would like to try for honors in physics, and I certainly would!

My research last semester--the required senior research course--was mostly my chance to learn some techniques and theory of quantum optics and computing.  I spent most of my time learning how to measure quantum states, a process called quantum state tomography, how to construct a quantum-optical apparatus, and a few examples of trying to minimize decoherence--when a wave packet gets connected to its environment.   These were all interesting things to learn, but I did very little to further my project's goal: creating arbitrary spatial mode and polarization states in a pair of entangle photons.

My talk at the end of the semester was titled "Generating Qubits for Quantum Computation with Biphotons", which is the end goal, but I mostly talked about the process of quantum tomography.  This semester, I'm hoping to work on much more.

Last semester, I was working only with polarization, that is, the orientation of the oscillations in the electric and magnetic fields that light is composed of.  This semester, if I can recreate my results from last semester sufficiently well in a new setup, I'll be adding spatial modes into the mix, which will increase the Hilbert space of the system to be 16-dimensional, if I understand the math right...

$$ \mbox{Two particles, two polarization states:} \mathcal{H} = \left(\begin{array}{l}|H_1\rangle\\|V_1\rangle\\\end{array}\right) \otimes \left(\begin{array}{l}|H_2\rangle\\|V_2\rangle\\\end{array}\right) = \left(\begin{array}{l}|H_1H_2\rangle\\|H_1V_2\rangle\\|V_1H_2\rangle\\|V_1V_2\rangle\\\end{array}\right)$$

$$ \mbox{Two particles, four states:} \mathcal{H}_{pol} \otimes \mathcal{H}_{mode} = \mathcal{H}^{16}$$

Which will require a much larger tomography process to read.  When there were only the two polarization states, a QST required 16 measurements of correlation between the system state and a selected state, and then some fancy linear algebra (not really that fancy, but...) before giving up the density matrix.  That was with a Hilbert space of dimension 4!  With one of dimension 16, I'm afraid it might take a whole 256 measurements... and I'm not sure I'm capable of that.

Vegan Drinking Food Night

posted on 2011-01-07 11:17:53

When I became vegetarian about six years ago, I started to learn that, while there are meat-substitutes, few of them are really the same.  Furthermore, when you're a bit repulsed by the idea of eating meat anyway, why would you want to eat something designed to be like meat anyway?That said, there are some flavors that you just don't get as easily anymore, and that's only gotten worse since I started trying to eat vegan this August.  As someone who used to get teased about how often he would suggest pizza, I find myself missing it a lot.  I still will eat it if it's available if someone else has purchased it, since then at least I'm not paying a company to keep a cow in a packed factory in terrible conditions (I am not sure if that's an accurate statement, I haven't read up on how cows are kept recently).  This post is not about pizza, but rather something I didn't even miss: Wings.

In believing that I am capable of being wrong, I've convinced myself that people around me should be able to do whatever they think it right, too, so I usually don't have that much of a problem with people eating meat around me.  Wings, though, have always disgusted me.  Watching someone tear flesh from the bone was disturbing even before I became vegetarian, let alone now, when it sometimes makes me feel nauseated.  A few days ago, though, I was trying to think of fun things to do with seitan and thought about wings.

A first search for vegan wings turned up recipes suggesting boiling the seitan, which is what I'd learned originally from Isa Moskowitz's Vegan with a Vengeance.  In my experience, though, that makes the seitan really spongy and not so interesting, and I prefer some of the methods used by the Vegan Dad, which is where I hit paydirt.

Despite missing a few spices, I improvised a bit and came up with these round balls of fake-chickeny-goodness... or grossness.  It's really hard to decide which it is, because they are sickeningly saucy and tasty.  I would never have imagined mixing margarine and bbq sauce had I not read that recipe.  Obviously I haven't had much experience with barbecue.

Hello world!

posted on 2011-01-07 10:35:30

Finally, after many many years since my last website, I will have some space of my own on the net again.  I've been frustrated with the limitations of just having a blogger blog for a while now, and NearlyFreeSpeech.net offers quite cheap hosting that I think even I can afford.  I found help for setting up WordPress here and it's been relatively easy from there.

Right now, I'm having difficulty getting WordPress to upload images, which is, apparently, some permissions error I'll have to resolve.  I'm sure it'll get sorted out and I can show you all pictures of food I cook and whatnot.

Time to go find a good theme and generally hack about!