When Quantum States Grow Macroscopic
Hui Deng
The physical world is best understood at its two limits: the macroscopic limit described by Newton's laws and Einstein's relativistic theories, and the microscopic limit described by quantum mechanics. Bridging these two limits are a few examples of 'macroscopic-sized quantum states'. I will introduce two types of systems that host such states. One is a solid-state counter-part of ultra-cold atomic gasses, where macroscopic quantum states spontaneously form through phase transitions. It provides a test bed of many-body physics, and promises device applications of quantum phases. The other consists of an ensemble of spins. Macroscopic quantum states are externally induced and manipulated by lasers, enabling robust quantum information processing.