Are complex emotions (love, hatred, jealousy, etc.) caused by intelligence? Can non-human minds have such emotions?

Non-human minds do have such emotions. In fact, you could observe the fact quite well, with pets. Dogs, specially are known to be emotionally attached to people, or their masters.
Also, elephants mourn for years after the death of a loved one.
And the way the lioness protects her cubs is very exemplary of the emotions contained in animals