Parametric Excitation and Instabilities of Spin Waves driven by Surface Acoustic Waves

微腔中的量子流体效应和参量不稳定性

Quantum fluid effects and parametric instabilities in microcavities

本文描述了近共振连续波泵浦激光注入微腔极化激元流体的非平衡性质。在第一部分中，我们指出了Bogolubov类极化激元激发的特殊色散和极化激元参数不稳定性之间的相互作用。我们显示如何集体激发光谱没有对应的平衡系统可以观察到通过调整激发角和频率。在第二部分中，我们解释了这些集体激发对极化激元流体的面内传输的影响。我们发现，由人工或天然缺陷引起的共振瑞利散射是一个非常敏感的工具，以显示迷人的效果，如极化激元超流性或极化激元切伦科夫效应。我们提出了一套全面的预测远场和近场图像的共振瑞利散射发射。

利用表面声波参量泵浦实现相干自旋波的持续放大

Sustained Amplification of Coherent Spin Waves by Parametric Pumping with Surface Acoustic Waves

本文提出利用行波表面声波作为非平稳泵浦，在钇铁石榴石薄膜中实现相干前向体静磁自旋波的持续参量放大，获得最高6 dB增益，并验证了三波混频机制，为集成磁子电路有源元件提供了可行方案。

Magnons Parametric Pumping in Bulk Acoustic Waves Resonator

We report on the experimental observation of excitation and detection of parametric spin waves and spin currents in the bulk acoustic wave resonator. The hybrid resonator consists of ZnO piezoelectric film, yttrium iron garnet (YIG) films on gallium gadolinium garnet substrate, and a heavy metal Pt layer. Shear bulk acoustic waves are electrically excited in the ZnO layer due to piezoeffect at the resonant frequencies of the resonator. The magnetoelastic interaction in the YIG film emerges magnons (spin waves) excitation by acoustic waves either on resonator's eigenfrequencies or the half-valu…

旋转模拟黑洞：准常态模式和尾部，超共振，以及排水浴缸声孔中的声波炸弹和植物

Rotating analogue black holes: Quasinormal modes and tails, superresonance, and sonic bombs and plants in the draining bathtub acoustic hole

声波传播和光波之间的相似性导致了对声孔的研究，声孔是黑洞的声学类似物。许多黑洞的特征在声孔中都有对应物。克尔度规，广义相对论中黑洞的旋转度规，与排水浴缸度规，一个旋转声孔的度规类似。在这里，我们报告的进展，已在理解的功能，如准正规模式和尾巴，超共振，不稳定性时，孔被反射镜包围，在排水浴缸度量。如果设置正确，人们就可以从这些不稳定性中建立起一种以放大的声波形式储存能量的装置。这可以被用于邪恶的目的，如在炸弹中，或在声波工厂中获得良好的利润。

Dynamically Tuned Arrays of Polariton Parametric Oscillators

Optical parametric oscillations (OPOs) - a non-linear process involving the coherent coupling of an optically excited two particle pump state to a signal and an idler states with different energies - is a relevant mechanism for optical amplification as well as for the generation of correlated photons. OPOs require states with well-defined symmetries and energies: the fine-tuning of material properties and structural dimensions to create these states remains a challenge for the realization of scalable OPO-based functionalities in semiconductor nanostructures. Here, we demonstrate a pathway towa…