Tunnelling of molecules and quantum decay

在我们的日常经验中，被困在能量井中的粒子只有当它们拥有比能量屏障更多的能量时才能逃脱；被困在碗里的大理石一直呆在里面，除非它有足够的能量升到碗的顶部并出来。对于微观粒子来说，即使其能量低于势垒，粒子也有可能逃逸。这种现象被称为“隧道效应”。隧道效应几乎只针对单个粒子进行了研究。对分子隧穿的研究是最近才开始的。最简单的分子由两个原子组成，因此具有拉长的结构：这就是使分子隧穿研究有趣和具有挑战性的原因。为了逃脱能垒内的限制，两个原子都需要挖隧道出来，这有几种方法可以实现。例如：分子分裂成两个原子。

In our everyday experience, particles trapped inside energy wells can escape only if they have more energy than the energy barrier; a marble trapped in a bowl stays inside unless it has enough energy to rise to the top of the bowl and get out. For microscopic particles it is possible for a particle to escape even if its energy is less than the barrier. This phenomenon is call "tunnelling." Tunnelling has been investigated almost solely for single particles. Investigations into the tunnelling of molecules began relatively recently. The simplest molecule consists of two atoms and thus has an elongated structure: this is what makes the study of tunnelling of molecules interesting and challenging. In order to escape confinement inside an energy barrier, both atoms need to tunnel out, and there are several ways this can happen. For example: the molecule breaks up into two atoms.