Observation of Non-Classical Rotational Inertia in Bulk Solid 4He
Observation of Non-Classical Rotational Inertia in Bulk Solid 4He
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DOI：
10.1007/s10909-007-9471-1
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发表时间：
2006-07
影响因子：
2
通讯作者：
Motoshi Kondo;S. Takada;Y. Shibayama;K. Shirahama
中科院分区：
文献类型：
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作者：
Motoshi Kondo;S. Takada;Y. Shibayama;K. Shirahama
在Kim和Chan(KC)最近的扭转振子实验中，在多孔材料中的固体4He中观察到了转动惯量的减少(Kim，E.，Chan，M.H.W.in Natural 427：225,2004；J.Low Temp.太棒了。138：859,2005)和散装环形通道(Kim，E.，Chan，M.H.W.in Science 305：1941,2004)。这一观测结果有力地表明了固体4He中存在“非经典转动惯量”，即超流。为了研究这种可能的“超固态”相，我们对柱状固体4He样品进行了扭转振荡器实验。我们观察到两个固体样品(压力P=4.1和3.0 MK)的转动惯量在200 MK以下减小。在70nMK观察到的NCRI分数为0.14%，约为KC在环空中观察到的分数的三分之一。我们的观察是对KC可能的超固体发现的第一次实验证实。
In recent torsional oscillator experiments by Kim and Chan (KC), a decrease of rotational inertia has been observed in solid4He in porous materials (Kim, E., Chan, M.H.W. in Nature 427:225, 2004; J. Low Temp. Phys. 138:859, 2005) and in a bulk annular channel (Kim, E., Chan, M.H.W. in Science 305:1941, 2004). This observation strongly suggests the existence of “non-classical rotational inertia” (NCRI), i.e. superflow, in solid4He. In order to study such a possible “supersolid” phase, we perform torsional oscillator experiments for cylindrical solid4He samples. We have observed decreases in rotational inertia below 200 mK for two solid samples (pressuresP=4.1 and 3.0 MPa). The observed NCRI fraction at 70 mK is 0.14%, which is about 1/3 of the fraction observed in the annulus by KC. Our observation is the first experimental confirmation of the possible supersolid finding by KC.