A φ Josephson junction (pronounced ''
phi
Phi (; uppercase Φ, lowercase φ or ϕ; grc, ϕεῖ ''pheî'' ; Modern Greek: ''fi'' ) is the 21st letter of the Greek alphabet.
In Archaic and Classical Greek (c. 9th century BC to 4th century BC), it represented an aspirated voicele ...
Josephson junction'') is a particular type of the
Josephson junction
In physics, the Josephson effect is a phenomenon that occurs when two superconductors are placed in proximity, with some barrier or restriction between them. It is an example of a macroscopic quantum phenomenon, where the effects of quantum mech ...
, which has a non-zero
Josephson phase
In physics, the Josephson effect is a phenomenon that occurs when two superconductors are placed in proximity, with some barrier or restriction between them. It is an example of a macroscopic quantum phenomenon, where the effects of quantum mec ...
φ across it in the ground state. A
π Josephson junction, which has the minimum energy corresponding to the phase of π, is a specific example of it.
Introduction
The Josephson energy
depends on the superconducting phase difference (Josephson phase)
periodically, with the period
. Therefore, let us focus only on one period, e.g.
. In the ordinary Josephson junction the dependence
has the minimum at
. The function
: