DC Josephson effect

The DC Josephson effect refers to the phenomenon where a supercurrent—an electrical current that flows without resistance—can pass between two superconductors separated by a thin insulating layer, even though classical physics suggests that this shouldn't happen. This effect occurs without any applied voltage, hence "DC" for direct current. It is crucial for the operation of devices like quantum bits in superconducting qubits, which are used in quantum computing. Essentially, it demonstrates how quantum mechanics enables unusual electrical behaviors, leading to advancements in technology that rely on superconductivity.