Picosecond pulses from Josephson junctions: Phenomenological and microscopic analyses

摘要: A Josephson junction modeled by the phenomenological current relation together with internal resistance can exhibit pulses in voltage across when driven an oscillating source. These occur singly, pairs, triplets, etc. a repetition rate equal to twice driving frequency. The inclusion of capacitance and inductance generally degrades pulse characteristics, but attainable values for tunnel junctions are tolerable, typical parameter values, have picosecond widths. model becomes suspect on such time scales, however, because gap frequencies just under 1012Hz. Preliminary studies based microscopic tunnel-junction theory nevertheless show results qualitatively similar those Phenomenological model. effects resistor noise also been studied. It is concluded that well developed ps be created physical junctions.