Exam 2022

General information


This exam is published on Monday, Apr 28 at 09:00 hours. You can work on your solution till Sun May 01, 2022 at 23:00 (``the deadline''). Before the deadline you should submit your final report in the pdf-format and a zip-file containing the documented source code. For the names of the files, please use teh format "lastname_TFY4235_report.pdf" and "lastname_TFY4235_code.zip"; for those of you taking the course using the the FY8904 code, replace TFY4235 by this code. The submission of your work you will do via the system Inspera that you can find at https://ntnu.inspera.no/. You will receive an email at the start of the exam detailing how to log in to this system and how to submit your report via it.

Prior to the deadline you are also expected (Useful in the unlikely event that something should go wrong with the digital submission via "Inspera", or you cannot get it to work properly.), to email the final report and source code to me at Ingve.Simonsen@ntnu.no with subject TFY4235 or FY8904. (Warning: If your email is too large, the gmail system, to which I also forward my email, may notify you that the message was too large to be delivered to my gmail account. This means that your message was received successfully by the ntnu email system, if you were not informed otherwise.)

There are no constraints on the aids you may want to use in connection with this exam, including discussing it with anybody. However, the report and the computer code you will have to write yourself. Please attach your computer codes as appendices to the report as outlined above. Give as a footnote the names of your collaborators during the exam. The report may be written in either Norwegian (either variants) or in English.

There are no formal requirements for the format of the report in addition to what was said above. The report should explain what you have been doing, your results, and how you interpret these results. Details should be included to the extent that we as graders can follow your way of reasoning. General background theory that, for instance, can be found i textbooks, is not needed in the report. It is documentation of your work and how you were thinking in order to obtain the reported results that we are interested in! Remember that if you have written an original and/or clever code for solving the problem, but are not able to explain it well in the report, it is hard to give you full credit.

Should you run out of time, you are adviced to spend the time on properly explaning what you did and the results you obtained instead of following a strategy of doing a little bit here-and-there without much explanation.

Finally, information about the exam problems that is announced after the exam has started will appear under the heading Messages at the bottom of this page. The students are responsible for checking this information regularly.

Exam set 2022

  • The exam set for 2022 is available here!

Deadline

  • Sun. May 01, 2022 at 23:00

Messages

  • At least one student misunderstood the statement we give regarding the suggested parameters in Sec. 3.1. (J = 1meV, dz = 0.1J etc.). We did not initially notice this ambiguity. As a result a few sentences in Sec 3.1. have been modified to remove it and some of the suggested parameter values have been adjusted slightly for your convenience. The main point is that J = 1meV, dz = 0.1J that dz is 0.1 times the coupling constant J, NOT 0.1 Joule. From the modified text this should now be clear.
  • Concerning the phase transition part (g, h and i), you can expect runtimes longer than just a few minutes; depending on your system size and implementation, an hour for the plot in (h) is not unrealistic. Make sure that you take a long enough temporal average. Feel free to contact us via email if you have further questions!
  • Slight correction for Problem 2.4(f). The text leading up to this question it is said that you can assume "... an anisotropy term dz > 0, or an external magnetic induction field B = (0, 0, B0)...." For the case J>0 this is all right. However, for the case J<0 this does not work so well if B0 is different from zero. Hence for Problem 2.4(f) you should assume that an anisotropy term dz > 0 is present and no magnetic field. The exam problem has been updated to reflect this change.
  • We will organize a Question and Answer session Thu. Apr 28 in the lecture room (D1-102) between 15-17h. Here we will try to clarify potential issues that you have regarding understanding the exam questions.
  • When the Heun method is applied and a thermal noise term is included in the effective field it is stressed that the noise is not changed during a single Heun iteration described by Eqs. (7a) and (7b) [that is for both the predictor step and the corrector step]. This may not be totally clear from the text. However, it is stated in Ref. 3, 6 lines after Eq (18): "It should be noted that the random thermal field does not change between steps." Between Heun iterations the noise term should (but not within an iteration). Hopefully this is clarify.
  • The exam set is now published. Good luck!