# Margolus–Levitin theorem

The Margolus–Levitin theorem states that the processing rate of all forms of computation (including quantum computation) cannot be higher than about 6 × 1033 operations per second per joule of energy. The theorem is named for Norman Margolus and Lev B. Levitin, who derived this fundamental limit on the rate of computation.

Stating the bound for one bit is as follows:

A quantum system of energy E needs at least a time of ${\displaystyle {\frac {h}{4E}}}$ to go from one state to an orthogonal state, where h is the Planck constant (6.626×10−34 J⋅Hz−1[1]) and E is average energy.

• Norman Margolus, Lev B. Levitin (1998). "The maximum speed of dynamical evolution". Physica D. 120 (1–2): 188–195. arXiv:quant-ph/9710043. Bibcode:1998PhyD..120..188M. doi:10.1016/S0167-2789(98)00054-2. S2CID 468290.{{cite journal}}: CS1 maint: uses authors parameter (link)