text: This phenomenon gives rises to the inversion of the nitrogen atom in an ammonia molecule, splitting the ground state vibrational level.
full_question: This phenomenon gives rises to the inversion of the nitrogen atom in an ammonia molecule, splitting the ground state vibrational level. In a device that relies on this process, an increase in voltage is accompanied by a decrease in current, forming a region of negative resistance. This process is responsible for a form of magnetoresistance used by the read heads of hard drives. Finding the probability of this phenomenon is a prime application of the WKB approximation because it can be exact for this phenomenon. George Gamow was able to calculate the correct rate of alpha decay by supposing that this phenomenon was responsible. For10 points, name this purely quantum phenomenon in which a particle traverses a classically impenetrable barrier without going over it.
first_sentence: This phenomenon gives rises to the inversion of the nitrogen atom in an ammonia molecule, splitting the ground state vibrational level.
raw_answer: quantum mechanical tunneling