Brussaard P, Fisher S N, Guénault A M, Hale A J, Mulders N, Pickett G R
Department of Physics, Lancaster University, Lancaster, LA1 4YB United Kingdom.
Phys Rev Lett. 2001 May 14;86(20):4580-3. doi: 10.1103/PhysRevLett.86.4580.
We report the first measurements of the A-B phase transition of superfluid 3He confined within 98% silica aerogel in high magnetic fields and low temperatures. A disk of aerogel is attached to a vibrating wire resonator. The resonant frequency yields a measure of the superfluid fraction rho(s)/rho of the 3He within the aerogel. The inferred rho(s)/rho value increases substantially at the A-to- B transition of the confined superfluid, allowing us to map the A-B phase diagram as a function of field and temperature. At 4.8 bars, the B-T transition curve looks very similar to that in bulk with a simple reduction factor of order 0.45 for both transition field and temperature.
我们报告了在高磁场和低温下，被限制在98%二氧化硅气凝胶中的超流³He的A - B相变的首次测量结果。一片气凝胶附着在一根振动丝谐振器上。谐振频率给出了气凝胶内³He的超流分数ρ(s)/ρ的测量值。在受限超流的A到B相变处，推断出的ρ(s)/ρ值大幅增加，这使我们能够绘制出作为磁场和温度函数的A - B相图。在4.8巴时，B - T转变曲线与体材料中的曲线非常相似，转变场和温度的简单缩减因子约为0.45。
