A-A splitting in pure He in nematic aerogel

Here, we present the results of vibrating wire experiments in pure He (without He coverage) in nematic aerogel. We investigated the dependence of splitting of the superfluid transition temperature of He in aerogel on magnetic field. In addition to our previous work, we used a wider range of magnetic fields (up to 31 kOe) and managed to detect both the “upper” and “lower” superfluid transition temperatures. The solid paramagnetic He layer on the aerogel strands activates the magnetic scattering channel. According to theory, it should result in linear splitting at high (≥ 20 kOe) fields, while at lower fields the splitting is expected to be nonlinear. We were able to observe this nonlinearity, but we have a discrepancy with theoretical predictions regarding the range of fields where nonlinearity occurs. Possible reasons for this are discussed.