{{Short description|Computational complexity of quantum algorithms}}
'''Quantum complexity theory''' is athe partsubfield of [[computational complexity theory]] inthat [[theoretical computer science]]. Itdeals studieswith [[complexity classes]] defined using [[quantum computers]] and [[quantum information]], which are [[computational model]]s based on [[quantum mechanics]]. It studies the hardness of problems in relation to these complexity classes, and the relationship between quantum complexity classes and classical (i.e., non-quantum) complexity classes.
