Novel Oscillating Aerogel Experiments in Superfluid 3He at Ultralow Temperatures
Novel Oscillating Aerogel Experiments in Superfluid 3He at Ultralow Temperatures
复制标题
超低温超流体 3He 中的新型振荡气凝胶实验
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
G. Pickett
中科院分区：
文献类型：
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作者：
P. Brussaard;S. Fisher;A. M. Guénault;A. J. Hale;G. Pickett
我们在超流体 3He 中在超低温下振荡的 98% 气凝胶圆盘上进行了新颖的实验。气凝胶迪克连接到球门柱形振弦谐振器，并浸入由兰卡斯特式核冷却级冷却的液体 3He 中。在低压下，我们没有看到气凝胶内超流动性的证据，直到我们的基础温度低于<0.11Tc。在较高压力下，我们观察到较大的温度相关频移，让人想起扭转振荡器实验。我们发现 5 bar 下的转变温度约为 600μK。当气凝胶中的氦是超流体时，谐振器的响应是高度非线性的。谐振频率随着线振幅的增加而强烈降低。这提供了一种令人兴奋的新技术，用于测量超低温状态下气凝胶中 3He 的超流体特性。
We present novel experiments on a disk of 98% aerogel oscillating in superfluid 3He at ultralow temperatures. The aerogel dik is attached to a goal post shaped vibrating wire resonator and immersed in liquid 3He cooled by a Lancaster style nuclear cooling stage. At low pressures we see no evidence for superfluidity within the aerogel down to our base temperature of below <0.11Tc. At higher pressures we observe large temperature dependent frequency shifts, reminiscent of torsional oscillator experiments. We find the transition temperature at 5 bar to be around 600μK. The response of the resonator is highly non linear when the helium in the aerogel is superfluid. The resonant frequency decreases strongly with increasing wire amplitude. This offers an exciting new technique for measuring the superfluid properties of 3He in aerogel in the ultralow temperature regime.