论文标题
超级流体薄膜表面波的极端量子非线性
Extreme quantum nonlinearity in superfluid thin-film surface waves
论文作者
论文摘要
我们表明，高度狭窄的超流体膜是极其非线性的机械谐振器，提供了实现机械量子的前景。具体而言，我们考虑了第三次表面波，而范德华与底物的相互作用引入了非线性。将这些波限制在磁盘上，我们得出了分析表达式的立方和四分之一非线性，并确定它们引入的共振频率移动。我们预测单音偏移的三个数量级，比当前最新的非线性谐振器大三个数量级。结合超低氟化氦气的精致固有耗散以及声音晶体腔中强烈抑制的声学辐射损失，我们预测这可以允许声子以及两级系统样行为之间的封锁相互作用。我们的工作为极端机械非线性和使用机械谐振器作为Qubits的量子设备提供了新的途径。
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 new pathway towards extreme mechanical nonlinearities, and towards quantum devices that use mechanical resonators as qubits.
