User:Dahlia

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About me

My name is Dahlia and I am a first year grad student in chemistry. My specific program is called chemical physics. I just joined Eugene Shakhnovich's lab, where I plan to pursue theoretical biophysics. Top of Page

Fun facts on soft matter

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Final Project: FRUSTRATED SYSTEMS AND SOFT MATTER

My project concerns the very complex subject of frustration. I hope that I will be able to introduce the topic to you with some very simple spin systems, and then illustrate why this is important to soft matter!

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What is Frustration?

Frustration occurs in a myriad of different physical systems, ranging from polymer glasses, to proteins, to crystals. Although the mathematics and physics of very simple frustrated systems could be shown in various ways, I believe that the easiest way to present it is through the use of magnetic spins. All sorts of hard and soft-condensed matter systems have polarization, whether it be of magnetic spins, electron spin, charge, etc. Magnetism is a relatively easy way of illustrating the principles of frustration, thus I start with this. I'm assuming that everyone who reads this is familiar with the Ising model, but if you aren't there are lots of great statistical mechanics books that cover it in all its glory.

In its most general definition, when a system is in a frustrated state, it means that the minimum total energy of a system does not correspond to the sum of the minimum of all local interactions. Non-frustrated materials have a ground state that is characterized by a single potential well, which represents the uniform arrangement of perfectly ordered spins. By contrast, frustrated materials have a ground state that is an ‘energy landscape’ with many degenerate ground state configurations, separated by barriers of random height. This leads to low critical temperatures and strong dynamics at low temperatures.

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