Abstract
Within the framework of the Peyrard-Bishop model for DNA melting, sharp denaturation temperature profiles can currently be obtained only if anharmonic base-pair stacking interactions are considered. We show that, when solvent interactions are included, a sharp denaturation of the DNA double helix is obtained without the need for anharmonic nearest-neighbor interactions. Using the concept of pseudo-Schrödinger equations we discuss the analogy of these transition to quantum-mechanical tunneling, and in particular we show that the sharp transitions are similar to resonant tunneling.