Quantum speed limit theorems

The Margolus–Levitin theorem, named for Norman Margolus and Lev B. Levitin, gives a fundamental limit on quantum computation (strictly speaking on all forms on computation). The processing rate cannot be higher than 6 × 10³³ operations per second per joule of energy. Or stating the bound for one bit:

A quantum system of energy E needs at least a time of ${\frac {h}{4E}}$ to go from one state to an orthogonal state, where h = 6.626 × 10⁻³⁴ J·s is Planck's constant and E is average energy.

The theorem is also of interest outside of quantum computation, e.g. it relates to the holographic principle, digital physics, simulated reality, the mathematical universe hypothesis and pancomputationalism.

See also

• Koomey's law
• Limits to computation
• Moore's law

References

• "The maximum speed of dynamical evolution". Physica D. 120: 188–195. 1998. arXiv:quant-ph/9710043. Bibcode:1998PhyD..120..188M. doi:10.1016/S0167-2789(98)00054-2. {{cite journal}}: Cite uses deprecated parameter |authors= (help)
• Seth Lloyd and Y. Jack Ng, "Black Hole Computers," Scientific American (November, 2004), pp. 53–61.
• A 2002 MIT presentation on the quantum speed limit MURI2002_Lloydrevised.pdf (PDF)