Superfluid density ofHe3in 98% aerogel in small magnetic fields

E. Nazaretski, D. M. Lee, J. M. Parpia
2005 Physical Review B  
We performed low-frequency sound measurements on 3 He in 98% aerogel in a magnetic field that was varied between 0 and 2130 G at a fixed pressure of 27.9 bar. We monitor the frequency of the second sound like ͑slow͒ mode, which is the manifestation of superfluidity of 3 He in the presence of correlated disorder, and use its temperature dependence to calculate the superfluid fraction s / . We observed no field dependence of the s ͑T͒ / , other than an increase in the temperature range where the
more » ... re range where the A-like ͑A * ͒ phase is metastable. Both the A * and B phases have a smaller s ͑T͒ / than that of bulk 3 He, and the ratio s A * / s B is Ϸ0.5 over the whole temperature range. The A * phase does not reappear on warming from the B phase until a field in excess of 1270 Gauss is applied.
doi:10.1103/physrevb.71.144506 fatcat:2y4b2agabbcqplg5vbaqufexwu