⚡ JOSEPHSON JUNCTION — WASHBOARD POTENTIAL
JUNCTION PARAMETERS
Bias current I/Ic:
0.80
Damping β (1/Q):
0.20
Noise Γ:
0.02
Capacitance βc:
1.0
RESET
STOP
Phase φ:
—
Voltage ⟨V⟩:
—
State:
—
Josephson freq:
—
RSJ model:
βc φ̈ + φ̇ + sin(φ) = I/Ic + noise. The "tilted washboard" U(φ) = −EJ(cos φ + (I/Ic)φ). Below Ic: phase is locked (zero voltage). Above Ic: phase rolls (AC Josephson effect). Noise causes thermally activated phase slips. Underdamped (large βc): hysteresis between superconducting and resistive branches.