2011/06/30 by Gonzalo A. Alvarez, Dieter Suter
Physics and Astronomy · #quant-ph #cond-mat.mes-hall #physics.chem-ph
paper · pdf · doi:10.1103/physrevlett.107.230501
published as Phys. Rev. Lett. 107, 230501 (2011) · 4+ pages, 3 figures. New experimental data was added. New references added
arxiv created 2011/09/17 · arxiv updated 2011/12/02
Decoherence is one of the most important obstacles that must be overcome in quantum information processing. It depends on the qubit-environment coupling strength, but also on the spectral composition of the noise generated by the environment. If the spectral density is known, fighting the effect of decoherence can be made more effective. Applying sequences of inversion pulses to the qubit system, we generate effective filter functions that probe the environmental spectral density. Comparing different pulse sequences, we recover the complete spectral density function and distinguish different contributions to the overall decoherence.