Letter | Published:

New chiral phases of superfluid 3He stabilized by anisotropic silica aerogel

Nature Physics volume 8, pages 317320 (2012) | Download Citation

Abstract

A rich variety of Fermi systems condense by forming bound pairs, including high-temperature1 and heavy-fermion2 superconductors, Sr2RuO4 (ref. 3), cold atomic gases4 and superfluid 3He (ref.  5). Some of these form exotic quantum states with non-zero orbital angular momentum. We have discovered, in the case of 3He, that anisotropic disorder, engineered from highly porous silica aerogel, stabilizes a chiral superfluid state that otherwise would not exist. Furthermore, we find that the chiral axis of this state can be uniquely oriented with the application of a magnetic field perpendicular to the aerogel anisotropy axis. At sufficiently low temperature we observe a sharp transition from a uniformly oriented chiral state to a disordered structure consistent with locally ordered domains, contrary to expectations for a superfluid glass phase6.

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Acknowledgements

We are grateful to J. M. Parpia, V. V. Dmitriev, G. E. Volovik, N. Mulders, K. R. Shirer, A. M. Mounce and Y. Lee for discussion and to the National Science Foundation, DMR-1103625, DMR-0805277 and DMR-1106315, for support.

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  1. Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA

    • J. Pollanen
    • , J. I. A. Li
    • , C. A. Collett
    • , W. J. Gannon
    • , W. P. Halperin
    •  & J. A. Sauls

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Contributions

Experimental work and analysis was principally carried out by J.P. assisted by J.I.A.L. with further support from C.A.C. and W.J.G. Advice and assistance was provided by W.P.H. (experiment) and J.A.S. (theory).

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to W. P. Halperin.

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https://doi.org/10.1038/nphys2220

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