Quantum Rabi Oscillation Driven by Coherent Pulse Streams and the Permitted Depth of Quantum Logical Operation
Li Yang, Biyao Yang, Yufu Chen · arXiv (Cornell University) · 2010
Abstract Quantum Rabi oscillations driven by a coherent pulse stream is a basic atom-photon interaction process. It is widely used in various physical realization schemes of quantum computation. We show that the envelope of the population inversion is different from the Gaussian function, and approaching a tiny platform instead of revival pulses. As an example, we investigate the properties of this process within ion trap system. It is shown that when the wavelength of the driving field is of the order 10−6 m, the mean number of photons cannot be greater than 104 considering of the sideband transition in Cirac-Zoller scheme, and the failure probability of computing operation via QRO is of the order 10−2 after about 102 coherent 2π pulses. As the ion number of a trap increases, the failure probability of operation increases, which implies that for this scheme the scaling to largescale quantum computers is difficult. The conclusion we arrived at, based on the threshold theorem of fault-tolerant quantum computation, is that the quantum computations realized by Cirac-Zoller scheme at wavelength 10−6 m cannot be reliable for an algorithm if its number of Controlled-NOT operation on any physical qubit is greater than 102. This conclusion may be independent of any possible technical improvement in future.