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Kovachy et al. reply

Nature volume 537, pages E2–E3 (2016)Cite this article

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REPLYING TO D. M. Stamper-Kurn, G. E. Marti & H. Müller Nature 537, 10.1038/nature19108 (2016)

In the accompanying Comment1, Stamper-Kurn et al. assert that our observation of interference contrast in a half-metre-scale atom interferometer2 does not prove the existence of macroscopic quantum superpositions and, hence, does not test quantum mechanics at long length scales. Moreover, they imply that intrinsic atomic interactions or technical imperfections could prevent the application of our work to future differential measurements. In response, we argue: (i) that in standard quantum mechanics there is no known mechanism in our system that prohibits its use in future differential measurement applications; (ii) that our experiment tests quantum mechanics in that it constrains any modifications that would reduce contrast in an interferometer with arms that propagate over widely separated trajectories; and (iii) that, using a standard definition of superposition, our observation of interference results from quantum superposition at the half-metre scale. In particular, we argue that quantum superposition is a more general concept than first-order coherence.

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References

  1. Stamper-Kurn, D. M., Marti, G. E. & Müller, H. Verifying quantum superpositions at metre scales. Nature 537, http://dx.doi.org/10.1038/nature19109 (2016)

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Authors and Affiliations

  1. Department of Physics, Stanford University, Stanford, 94305, California, USA

    T. Kovachy, P. Asenbaum, C. Overstreet, C. A. Donnelly, S. M. Dickerson, A. Sugarbaker, J. M. Hogan & M. A. Kasevich

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  1. T. Kovachy
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  2. P. Asenbaum
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  3. C. Overstreet
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  4. C. A. Donnelly
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  6. A. Sugarbaker
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  7. J. M. Hogan
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  8. M. A. Kasevich
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Correspondence to M. A. Kasevich.

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Kovachy, T., Asenbaum, P., Overstreet, C. et al. Kovachy et al. reply. Nature 537, E2–E3 (2016). https://doi.org/10.1038/nature19109

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