Abstract

A Quantum Effect in the Classical Limit: Non-equilibrium Tunneling in the Duffing OscillatorAlec Maassen van den BrinkRCAS, Academia Sinica, Taiwanemail: [email protected] Duffing model is an oscillator with weak near-resonant driving, damping, and nonlinearity. For certain parameters, the stationary amplitude and phase bifurcate depending on initial conditions, and vary widely from one stable branch to the other. Due to this sensitivity, the system can be used for constructing detection devices.In recent years, an implementation using superconducting devices—the so-called Josephson bifurcation amplifier (JBA)—has been successfully used experimentally for superconducting qubit readout. In the experimental literature, the JBA is often taken as classical. However, for e.g. understanding how the stability of the stationary states is modified by tunneling, a proper quantum analysis is necessary. Such tunneling transitions would be an error process from the point of view of detecto