Superconducting Quantum Circuits

Josephson Junction & SQUID

Simulate Brian Josephson's 1963 Nobel discovery: Cooper pair quantum tunneling across a thin insulating barrier between two superconductors. Observe DC current $I = I_c \sin\phi$, AC oscillations $f_J = \frac{2eV}{h}$, and SQUID magnetometry.

Tunneling Current I 0.85 mA
AC Josephson Freq f_J 483.6 GHz
Phase Difference φ 0.32 π rad

Junction Setup

Visual Overlay

Controls

Josephson Relations & SQUID Equations

DC Josephson Relation: I(t) = I_c · sin(φ)
AC Josephson Relation: dφ / dt = (2e / ℏ) · V ⇒ f_J = (2e / h) · V = 483.6 GHz/mV
SQUID Max Current: I_max(Φ) = 2 I_c · |cos(π Φ / Φ₀)| where Φ₀ = h / 2e = 2.07 × 10⁻¹⁵ Wb
Developer Reference

Core Algorithm & Standalone Script

// Josephson junction Cooper pair quantum tunneling engine
const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');
// I = Ic * sin(phi), dphi/dt = (2e / hbar) * V