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ubermag / help

Repository for raising issues and requesting help on Ubermag
BSD 2-Clause "Simplified" License
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The exchange energy equation is inconsistent #98

Closed code-whale closed 3 years ago

code-whale commented 4 years ago

Dear Ubermag team, I typesystem.energy in simulation, but I found that there is a symbol in front of the exchange displayed, which is not consistent with what you have shown in the tutorial. Can you tell me why? image

marijanbeg commented 3 years ago

Hi @code-whale, there should be minus sign as a part of the exchange energy term. If you have seen a plus sign somewhere in the tutorials, then this is a mistake. Plus sign is when the exchange energy term is written using squared gradients. I hope this answers your question. If not, please let me know.

code-whale commented 3 years ago

@marijanbeg ,Thank you very much for your help! I will continue to learn about micromagnetism to help understand some phenomena in the simulation. If you can, can you tell me some books about micromagnetism or atomic spin? Because when I read the literature, I often see a lot of formulas and modeling that I don't understand. Thank you again for your kind help!