Optimized pulse sequences for suppressing unwanted transitions in quantum systems

TL;DR

This paper demonstrates that the Uhrig pulse sequence is optimal for suppressing unwanted transitions in quantum systems, offering significant improvements over traditional equidistant sequences through destructive interference effects.

Contribution

The study proves the optimality of the Uhrig pulse sequence for transition inhibition and provides exact analytical results supported by numerical confirmation.

Findings

Uhrig sequence outperforms equidistant sequences in transition suppression

Exact analytical results for transition inhibition are derived

Numerical simulations confirm the theoretical advantages of the Uhrig sequence

Abstract

We investigate the nature of the pulse sequence so that unwanted transitions in quantum systems can be inhibited optimally. For this purpose we show that the sequence of pulses proposed by Uhrig [Phys. Rev. Lett. \textbf{98}, 100504 (2007)] in the context of inhibition of environmental dephasing effects is optimal. We derive exact results for inhibiting the transitions and confirm the results numerically. We posit a very significant improvement by usage of the Uhrig sequence over an equidistant sequence in decoupling a quantum system from unwanted transitions. The physics of inhibition is the destructive interference between transition amplitudes before and after each pulse.