Emulating a Qubit with a Minimalist LC Circuit and a Single Varactor Diode

This study presents a classical analog emulator of a quantum bit (qubit) using an ultra-simple LC circuit with a varactor diode. By exploiting the diode’s nonlinear capacitance, the circuit replicates key qubit phenomena—including Rabi oscillations and Ramsey fringes—without requiring quantum hardware. The minimalist design (only 3 components, <$10 cost) and SPICE-compatible simulations make it an accessible educational tool for teaching quantum computing principles. This work bridges theoretical quantum mechanics and hands-on electronics, offering a practical alternative to cryogenic qubit systems. Note: This is a classical simulation and does not generate genuine quantum effects.