Extreme quantum nonlinearity in superfluid thin-film surface waves
Extreme quantum nonlinearity in superfluid thin-film surface waves
复制标题
DOI：
10.1038/s41534-021-00393-3
复制
发表时间：
2020-05
影响因子：
7.6
通讯作者：
Y. Sfendla;C. Baker;G. Harris;L. Tian;R. A. Harrison;W. Bowen
中科院分区：
文献类型：
--
作者：
Y. Sfendla;C. Baker;G. Harris;L. Tian;R. A. Harrison;W. Bowen
我们发现，高度受限的超流膜是非常非线性的机械谐振器，提供了前景，实现一个机械量子比特。具体来说，我们认为第三声表面波，与非线性引入的货车范德华相互作用与基板。将这些波限制在一个圆盘上，我们推导出三次和四次非线性的解析表达式，并确定它们引入的共振频率偏移。我们预测的单声子的位移是三个数量级大于目前最先进的非线性谐振器。结合超流氦极低的固有耗散和声子晶体腔中强烈抑制的声辐射损失，我们预测这可能允许声子之间的阻塞相互作用以及两级系统的行为。我们的工作为极端的机械非线性和使用机械谐振器作为量子比特的量子器件提供了一条途径。
We show that highly confined superfluid films are extremely nonlinear mechanical resonators, offering the prospect to realize a mechanical qubit. Specifically, we consider third-sound surface waves, with nonlinearities introduced by the van der Waals interaction with the substrate. Confining these waves to a disk, we derive analytic expressions for the cubic and quartic nonlinearities and determine the resonance frequency shifts they introduce. We predict single-phonon shifts that are three orders of magnitude larger than in current state-of-the-art nonlinear resonators. Combined with the exquisitely low intrinsic dissipation of superfluid helium and the strongly suppressed acoustic radiation loss in phononic crystal cavities, we predict that this could allow blockade interactions between phonons as well as two-level-system-like behavior. Our work provides a pathway towards extreme mechanical nonlinearities, and towards quantum devices that use mechanical resonators as qubits.