SUPERCURRENT AND ITS QUANTUM-STATISTICAL PROPERTIES IN MESOSCOPIC JOSEPHSON-JUNCTION IN THE PRESENCE OF NONCLASSICAL LIGHT FIELDS

In this paper, we study the supercurrent in a mesoscopic Josephson jun ction (MJJ) and its quantum statistical properties in the presence of nonclassical light fields. We investigate in detail the influence of e xternal nonclassical light fields on current-voltage step structures o f the MJJ. We also study in detail quantum statistical properties of t he supercurrent when the external quantum electromagnetic fields are e ven and odd coherent-state light fields. It is shown that the supercur rent in the MJJ exhibits both squeezing effect and quantum coherence. It is demonstrated that the MJJ can feel the difference not only betwe en classical light fields and nonclassical light fields but also betwe en different nonclassical light fields.