Selective darkening of degenerate transitions demonstrated with two superconducting quantum bits

P. C. De Groot, J. Lisenfeld, R. N. Schouten, Sahel Ashhab, A. Lupaşcu, C. J P M Harmans, J. E. Mooij

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45 Citations (Scopus)

Abstract

Controlled manipulation of quantum states is central to studying natural and artificial quantum systems. If a quantum system consists of interacting subunits, the nature of the coupling may lead to quantum levels with degenerate energy differences. This degeneracy makes frequency-selective quantum operations impossible. For the prominent group of transversely coupled two-level systems, that is, qubits, we introduce a method to selectively suppress one transition of a degenerate pair while coherently exciting the other, effectively creating artificial selection rules. It requires driving two qubits simultaneously with the same frequency and specified relative amplitude and phase. We demonstrate our method on a pair of superconducting flux qubits. It can directly be applied to the other superconducting qubits, and to any other qubit type that allows for individual driving. Our results provide a single-pulse controlled-NOT gate for the class of transversely coupled qubits.

Original languageEnglish
Pages (from-to)763-766
Number of pages4
JournalNature Physics
Volume6
Issue number10
DOIs
Publication statusPublished - 1 Oct 2010
Externally publishedYes

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ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

De Groot, P. C., Lisenfeld, J., Schouten, R. N., Ashhab, S., Lupaşcu, A., Harmans, C. J. P. M., & Mooij, J. E. (2010). Selective darkening of degenerate transitions demonstrated with two superconducting quantum bits. Nature Physics, 6(10), 763-766. https://doi.org/10.1038/nphys1733