Maximum speed of quantum gate operation
arXiv:quant-ph/0211167
Abstract
We consider a quantum gate, driven by a general time-dependent Hamiltonian, that complements the state of a qubit and then adds to it an arbitrary phase shift. It is shown that the minimum operation time of the gate is tau = (h/4E)(1+2 theta/pi), where h is Planck's constant, E is the average over time of the quantum-mechanical average energy, and theta is the phase shift modulo pi.
5 page Latex w/ macro file latex-3.tex. Full paper for QS2002 (Quantum Structures) proceedings. This revision fixes two small typos