Synthesising quantum states of sound and listening to what they tell us about the universe

薛定谔-猫的思想实验臭名昭著地突显了量子力学可以多么离奇，以及我们对我们世界的量子和经典方面之间的模糊边界知之甚少。利用量子技术和我们现在精湛的能力来控制光的量子方面，这个项目将通过在温度冷却到接近绝对零度的微小晶体中创建高频声波的量子态来照明和检查这一边界。这些量子声波将由数万亿个原子组成--从量子领域的角度来看，这是一个真正巨大的质量尺度，通常只包含非常少量的粒子或原子，但它只是我们日常世界的边缘，因为这些质量只占一根猫毛的一小部分。在这种质量尺度上产生和研究量子行为将成为一种新的强大的透镜，我们可以通过它来研究物理学的基础，并揭示出我们亟需的光：为什么我们在我们的日常世界中看不到量子行为？为什么量子态如此脆弱？那么，在这个神秘的边界上，地心引力是否起到了作用呢？

The Schrodinger-cat thought experiment infamously highlights how bizarre quantum mechanics can be and just how little we know about the fuzzy boundary between the quantum and classical aspects of our world. Using quantum technologies and our now exquisite ability to control the quantum aspects of light, this project will illuminate and examine this boundary by creating quantum states of high-frequency sound waves in a tiny crystal cooled to near absolute zero in temperature. These quantum sound waves will comprise trillions of atoms--a mass-scale that is truly gigantic from the perspective of the quantum realm, which usually only contains a very small number of particles or atoms, but is just on the edge of our everyday world, as that mass would make up just a small fraction of a single feline hair. Generating and studying quantum behaviour at this mass-scale will act as a new and powerful lens through which we can examine the very foundations of physics and shed much needed light on: Why do we not see quantum behaviour in our everyday world? Why are quantum states so fragile? And, does gravity even play a role at this mysterious boundary?