Two-particle tunneling current in Josephson junctions
Abstract
The contribution to the tunneling current of a Josephson junction from the Two-particle tunneling, to the 2nd order approximation in the barrier transparency, is investigated. Expressions for the current onset amplitudes corresponding to eV = Δ1,2 are given together with the full expressions for the voltage and the temperature dependencies of the two-particles current. The theory has ben developed to take also into account corrections due to depairing mechanisms, which lead to the smearing of the current singularities. Introducing a depairing parameter Γ, which accounts for the probability of these processes, I-V curves in the voltage region of the onset of single and two particle current are obtained. It is shown that, though having the same functional dependence, spreading occurs over a voltage range of different widths. In particular, it is shown that the width of the single-particle structure is twice larger the one for the two-particle. A careful investigation of the I-V curves in the region 2 Δ-eV ≪ Δ is presented and some aspects of the interesting voltage region near ¦Δ1-Δ2¦ is discussed.
- Publication:
-
Journal of Low Temperature Physics
- Pub Date:
- April 1995
- DOI:
- 10.1007/BF00753622
- Bibcode:
- 1995JLTP...99...81O
- Keywords:
-
- Magnetic Material;
- Order Approximation;
- Versus Curve;
- Functional Dependence;
- Voltage Range