To calculate a current named for this phenomenon, John Bardeen used a time-dependent perturbation in his transfer Hamiltonian method. Fowler and Nordheim modeled field emission using this phenomenon, which (-5[1])causes Esaki diodes to exhibit a negative differential resistance. In a Nobel-Prize-winning device developed by Binning and Rohrer, (-5[1])electrons undergo this phenomenon to induce a current in a conducting microscope tip. In an (10[1])alpha (10[1])decay theory posited by George (10[1])Gamow, helium nuclei undergo this phenomenon to escape Coulombic interactions, meaning there is a nonzero wavefunction outside of a finite square well. (10[1])For 10 points, name this (10[1])quantum phenomenon where a particle passes through a classically (10[1])forbidden barrier. ■END■ (10[1])