Quantum superpositions occur naturally in the tiny world of atoms, but as objects get bigger, heat and other external influences more easily disrupt these delicate states. Researchers have devised strategies for cooling nanometer-size slivers nearly to the point at which quantum effects take over. Micrometer-size mirrors are an even bigger challenge: in principle, light alone could disrupt them. A mirror can act as a sort of plunger that caps a cavity full of photons. If the mirror's vibrations happen to drive it outward, some photons escape the cavity, and the plunger feels a resulting suction force as the pressure inside the cavity diminishes. If the mirror moves into the cavity, pressure builds and pushes it back out. Either process would damp down the mirror's motions and keep it still.
Chill a bacterium-size mirror to a cold enough temperature and it will begin to quiver not from heat but from its quantum state--a so-called superposition in which the object is both vibrating and still. Aside from the experimental thrill of conjuring up quantum states in big, messy things, such ultracold objects could form the foundation of exquisitely fine sensors for weighing individual atoms. Three new studies show that researchers are making headway in their efforts to create nearly quiverless mirrors.
Here is the story
Cold Quantum Mirrors
Re: Cold Quantum Mirrors
