Department of Physics Monte Carlo simulations of Critical Phenomena in Physics

Note on lab I

1. For the first lab I want a short report. Use the following guidlines:
   • It should be possible to read the report without looking at the lab instructions.
   • Introduce/explain all symbols that are used in the text.
   • The text need not be accessible to fellow students who have not taken this course but it should be possible for you to understand it yourself if you find your report later, say in a few years time.
2. You also have to supply your computer code. It is important that it is easy to read the code. Consider the following points:
   • The code needs to be indented to clarify the structure.
   • Choose variable names with care.
   • Avoid complicated expressions that do many things in one go, rather define new variables with good names that makes it easy to see what happens.
   • Try to consider the execution speed e.g. by avoiding calculating the same thing more than once.
3. For the determination of the exponent β:
   • Be careful to use a precise value the critical temperature: T_c = 2.26926.
   • Skip the one or two points closest to T_c that are affected by the finite size. (Make use of the data for the smaller sizes to learn about the finite size effect.)
   • Don't use data too far from T_c in the fit ln m = C + β ln (T_c-T).
   • Use logarithmic scales on the axes in the figure that shows the determination of β.

Department of Physics Umeå University Last changed: 2020-04-23 Responsible for this page: Peter Olsson