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Bose-Einstein Condensate in Solid Helium

S. O. Diallo·J. V. Pearce·R. T. Azuah·O. Kirichek·J. W. Taylor·H. R. Glyde
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Abstract

We present neutron scattering measurements of the atomic momentum distribution, n(k), in solid helium under a pressure p = 41 bars and at temperatures between 80 mK and 500 mK. The aim is to determine whether there is Bose-Einstein condensation (BEC) below the critical temperature, T_c = 200 mK where a superfluid density has been observed. Assuming BEC appears as a macroscopic occupation of the k = 0 state below T_c, we find a condensate fraction of n_0 = (-0.10 \pm 1.20)% at T = 80 mK and n_0 = (0.08\pm0.78)% at T = 120 mK, consistent with zero. The shape of n(k) also does not change on crossing T_c within measurement precision.

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S. O. Diallo, J. V. Pearce, R. T. Azuah, O. Kirichek, J. W. Taylor, H. R. Glyde. 2007-02-14. Bose-Einstein Condensate in Solid Helium. https://doi.org/10.1103/physrevlett.98.205301

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