Odd-frequency pairing state in superconducting junctions Original Research Article

Using the quasiclassical Greenʹs function formalism, we study the induced odd-frequency pairing states in ballistic normal metal–superconductor (N/S) junctions where a superconductor has even-frequency symmetry in the bulk and a normal metal layer has an arbitrary length. We show that the concept of the odd-frequency pairing state plays an important role to interpret a McMillan–Rowell bound state in the normal metal.