What isn't clear is who takes care of the children before you get home from work. If your wife takes care of them all day, and then you get home and enjoy time with them, then she should realize they're just attached to both of you, the way children are supposed to be attached to both parents. Children that age (and especially three- and four-year-olds) enjoy having special time with each parent individually. If she stays home and takes care of them each day (and if she gives them plenty of "quality" attention), then she should just understand that kids love both parents (particularly once they're past being babies, who are particularly attached to their mother). I'm wondering if you and/or or your wife are placing more significance on the fact that your kids are just used to you being the one to "take over" once you're home. Kids go with whatever they think "the program is".
On the other hand, if she works and isn't with them all day, then maybe she needs to spend more time with them in the evening. That's the only time, each day, there would be for "quality time"; so if she doesn't have that with them then that could be one reason for what's going on.
Another possibility might be that you mean well and love your children but do "take over" more than she really wants. You deserve (and they need) "quality time" with you, but they also need that kind of time with both you and her. If she's feeling pushed aside by your well intended enthusiasm for caring for your children she may actually have good reason to feel a little resentful. When my children were young my husband worked long hours and was exhausted when he got home. I was just as pleased to be the one who always took care of them. I, of course, wanted him to be close to them; but the mother/child bond is powerful and can kind of "call" mothers to a certain amount of "required time".
I wonder if she isn't really "jealous" of you and the children, and if, instead, she's just angry that the children's relationship with her is being overlooked after 5. I don't know how correctly or incorrectly about guessed about any of these things, but sincerest best wishes on working it out.