text: An increase in this quantity can improve the mobility of graphene devices to clean them through "annealing.
full_question: An increase in this quantity can improve the mobility of graphene devices to clean them through "annealing." Free layers are aligned in a stationary state along their hard axis by the "clocking" value of this quantity, whose "switching" magnitude causes the NOT gate of a free layer to reverse from 0 to 1 in a magnetic tunnel junction. Spin-transfer torque is generated by the polarization of this quantity. This quantity is amplified via secondary emission in a photomultiplier tube. The sensitivity of a photodiode can be improved by minimizing the "dark" form of this quantity. This quantity increases exponentially when a reverse-biased diode is subjected to avalanche breakdown. A version of it is equal to epsilon-naught times the time derivative of the electric field and was developed because a certain equation fails when describing circuits with capacitors. For 10 points, name this quantity that is related to the magnetic field around a closed loop by Ampère's Law.
first_sentence: An increase in this quantity can improve the mobility of graphene devices to clean them through "annealing.
raw_answer: electric current [or I; or current density; or J; or displacement current]