Sawtooth current-phase relation of a superconducting trilayer system described using Ohta’s formalism

Calculation of Josephson Current in a Two-Barrier Tunnel Junction

“…This relation agrees with the known formula for the SIS junction obtained in the work by Kulik and Omelyanchuk [17]. The critical current, max , is determined from the extremum condition for expression (12) as a function of the phase difference. The phase difference, at which the current is maximum, depends on the barrier transparency, as well as on the junction parameters and the temperature.…”

“…Another peculiarity of the Josephson effect in the SISIS tunnel junction is a non-sinusoidal dependence of the current on the phase difference. A similar dependence was obtained in works [12,13] on the basis of the classical Ohta model [14]. The experimental observation of a non-sinusoidal dependence of the current through a two-barrier superconductor junction was described in works [15,16].…”

“…Formula (12) describes the dependence of the Josephson current density at the SISIS tunnel junction edges on the coherent phase difference and the barrier parameters, as well as the temperature. In the case = 1, formula (12) reads…”

Magnetic states of a rf superconducting quantum interference device containing a double-barrier Josephson junction

“…In accordance to this hypothesis, the CPR derived in Ref. 8 consists of the usual sinusoidal term, accounting for the superconducting coupling of the outermost electrodes, and of an additional half harmonic term, taking account of the coupling between adjacent superconducting layers in the SISIS structure. The properties of dc SQUIDs, when one junction is substituted with a DBJJ, have been studied in Ref.…”

“…[4][5][6][7] Very recently, a double-barrier Josephson junction ͑DBJJ͒ has been shown to have a nonsinusoidal current-phase relation ͑CPR͒. 8 The properties of DBJJs had already been studied both experimentally and theoretically before. [9][10][11] In particular, in their experimental studies, Nevirkovets et al 9 noticed that new effects appear when the thickness of the middle layer of a SISIS structure ͑where S stands for superconducting layer and I for insulating interface͒ is of the order of the coherence length of the superconducting material in the trilayer.…”