Laser cooling and control of excitations in superfluid helium
Laser cooling and control of excitations in superfluid helium
复制标题
DOI：
10.1038/nphys3714
复制
发表时间：
2016-08-01
期刊：
影响因子：
19.6
通讯作者：
Bowen, W. P.
中科院分区：
文献类型：
--
作者：
Harris, G. I.;McAuslan, D. L.;Bowen, W. P.
超流性是物质的一种量子态，在低温下宏观地存在于氦中。超流氦中的元激发已经用中子和光散射等技术成功地探测过。然而，声子激发的测量到目前为止仅限于平均热力学性质或远离热平衡的驱动响应。在这里，我们使用腔光学力学探测声子激发的热力学在真实的时间。此外，强的光-物质相互作用允许激光冷却和放大。这代表了一种观察和控制超流体激发的新工具，可以深入了解声子-声子相互作用，量子化涡旋和二维现象，如Berezinskiii-Kosterlitz-无相变。这里研究的第三种声音模式也提供了一个途径，量子光学力学与薄超流膜，包括前景的毫微微克质量，高机械品质因数，强声子声子和声子涡旋相互作用，并自组装成复杂的几何形状与亚纳米特征尺寸。
Superfluidity is a quantum state of matter that exists macroscopically in helium at low temperatures. The elementary excitations in superfluid helium have been probed with great success using techniques such as neutron and light scattering. However, measurements of phonon excitations have so far been limited to average thermodynamic properties or the driven response far out of thermal equilibrium. Here, we use cavity optomechanics to probe the thermodynamics of phonon excitations in real time. Furthermore, strong light-matter interactions allow both laser cooling and amplification. This represents a new tool to observe and control superfluid excitations that may provide insight into phonon-phonon interactions, quantized vortices and two-dimensional phenomena such as the Berezinskii-Kosterlitz-Thouless transition. The third sound modes studied here also offer a pathway towards quantum optomechanics with thin superfluid films, including the prospect of femtogram masses, high mechanical quality factors, strong phonon-phonon and phonon-vortex interactions, and self-assembly into complex geometries with sub-nanometre feature size.