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arXiv · 1110.5262

Multiple-spin coherence transfer in linear Ising spin chains and beyond: numerically-optimized pulses and experiments

Manoj Nimbalkar·Robert Zeier·Jorge L. Neves·S. Begam Elavarasi·Haidong Yuan·Navin Khaneja·Kavita Dorai·Steffen J. Glaser
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Abstract

We study multiple-spin coherence transfers in linear Ising spin chains with nearest neighbor couplings. These constitute a model for efficient information transfers in future quantum computing devices and for many multi-dimensional experiments for the assignment of complex spectra in nuclear magnetic resonance spectroscopy. We complement prior analytic techniques for multiple-spin coherence transfers with a systematic numerical study where we obtain strong evidence that a certain analytically-motivated family of restricted controls is sufficient for time-optimality. In the case of a linear three-spin system, additional evidence suggests that prior analytic pulse sequences using this family of restricted controls are time-optimal even for arbitrary local controls. In addition, we compare the pulse sequences for linear Ising spin chains to pulse sequences for more realistic spin systems with additional long-range couplings between non-adjacent spins. We experimentally implement the derived pulse sequences in three and four spin systems and demonstrate that they are applicable in realistic settings under relaxation and experimental imperfections-in particular-by deriving broadband pulse sequences which are robust with respect to frequency offsets.

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Manoj Nimbalkar, Robert Zeier, Jorge L. Neves, S. Begam Elavarasi, Haidong Yuan, Navin Khaneja, Kavita Dorai, Steffen J. Glaser. 2011-10-24. Multiple-spin coherence transfer in linear Ising spin chains and beyond: numerically-optimized pulses and experiments. https://doi.org/10.1103/physreva.85.012325

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