All the textbooks I saw are very clear about the implications of commutating operators in quantum mechanics. However, much less is said about anti-commutation relations. Does it have a general implication if two operators anti-commutate?

  • $\begingroup$ For fermionic operators to anticommute is equally natural and "classical" as for bosonic ones to commute. If you construct an actual number as a product of an even number of fermionic operators, this number will indeed commute with other numbers if the factors commute or anticommute. In fact, with some contrived (and not canonical) redefinitions of signs, anticommuting operators may be converted to commuting ones. It's just much more natural to use anticommuting numbers for fermions. $\endgroup$ Dec 15, 2011 at 6:35

1 Answer 1


1) For fermionic operators, the important object is the anti-commutator, not the commutator, see e.g. this question.

2) However, since OP did not mention fermionic operators explicitly, it seems that OP is asking of the role of anticommutators for bosonic fields only.

3) In the case of uncertainty relations, see e.g. this question.

4) Finally, it should also be mentioned that the defining relation of a Clifford algebra uses an anti-commutator.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.