Unification of Quantum Advantage in Mechanical Tasks

Quantum physics predicts many weird behaviours which can be turned into advantages in computing and communication tasks. Bits in a quantum computer can be zero and one at the same time, which can be used to solve problems faster than everyday computers. Two quantum objects can instantly affect each other over large distances, which can be used to communicate secrets that are impossible to eavesdrop without breaking the laws of physics. Such quantum behaviours have been demonstrated with tiny objects like atoms, molecules, and microscopic electrical circuits. However, they have not been shown in larger objects. Why, then, does this quantum weirdness contradict our everyday experience? Could it be that quantum physics stops working when objects become too big? Can we also observe quantum properties in mesoscopic objectslarger (but not so large) things we can see without the help of microscopes? These questions can be addressed using mechanical taskstasks involving objects in motion, like throwing a ball or observing the swing of the pendulum on a grandfather clock. Quantum theory predicts that quantum objects offer advantages in such tasks: a thrown quantum ball can travel further than we expect, and a swung quantum pendulum can be found more often on one side of the clock than the other. It is straightforward to carry out these mechanical tasks with mesoscopic objects, as they only involve steps that are already done in the lab: like letting go of an object and recapturing it, or looking at how an object moves around in a trap. As such, the introduction of such tasks paves the way towards the demonstration of quantum advantage with objects that we can actually see with our naked eyes. The primary goal of this project is to investigate the theory behind mechanical tasks, propose possible methods to demonstrate these effects with mesoscopic objects in the lab, and study how real-life imperfections affect the amount of quantum advantage present. Meanwhile, it is harder to demonstrate advantages in computing and communication tasks with mesoscopic objects, as larger objects can be difficult to control, while such tasks can have more demanding requirements than mechanical tasks. As such, another goal of this project is to study the relationship between the quantum advantage in mechanical tasks and the more familiar quantum weirdness in computing and communication tasks. From these relationships, advantages in mechanical tasks can indirectly demonstrate advantages in computing and communication tasks. Therefore, if and when experiments of mechanical tasks involving mesoscopic objects are successfully performed, they will prove that quantum weirdness, in all its many forms, are indeed present in objects large enough for us to see.