alt=Diagram of randomised complexity classes|thumb|upright=1.25|BQP in relation to other probabilistic complexity classes (ZPP, RP, co-RP, BPP, PP), which generalise P within PSPACE. It is unknown if any of these containments are strict. In computational complexity theory, bounded-error quantum polynomial time (BQP) is the class of decision problems solvable by a quantum computer in polynomial time, with an error probability of at most 1/3 for all instances.Michael Nielsen and Isaac Chuang (2000). Quantum Computation and Quantum Information. Cambridge: Cambridge University Press. . It is the quantum analogue to the complexity class BPP.
alt=diagram of randomised complexity classes|thumb|upright=125|bqp in relation to other probabilistic complexity classes (zpp rp co-rp bpp pp) which generalise p within pspace it is unknown if any of these containments are strict in computational complexity theory bounded-error quantum polynomial time (bqp) is the class of decision problems solvable by a quantum computer in polynomial time with an error probability of at most 1/3 for all instancesmichael nielsen and isaac chuang (2000) quantum computation and quantum information cambridge cambridge university press  it is the quantum analogue to the complexity class bpp