Sharp tunneling peaks in a parametric oscillator: quantum resonances missing in the rotating wave approximation

TL;DR

This paper uncovers a new tunneling mechanism in a parametric oscillator caused by fast oscillating terms ignored in the RWA, leading to resonant peaks with significantly enhanced tunneling amplitudes.

Contribution

It introduces a novel tunneling mechanism driven by resonant transitions from fast oscillating terms, surpassing the predictions of the rotating wave approximation.

Findings

Resonant peaks in tunneling amplitude as a function of modulation frequency

Enhanced tunneling amplitudes near resonance maxima

Identification of a tunneling mechanism beyond RWA predictions

Abstract

We describe a new mechanism of tunneling between period-two vibrational states of a weakly nonlinear parametrically modulated oscillator. The tunneling results from resonant transitions induced by the fast oscillating terms conventionally disregarded in the rotating wave approximation (RWA). The tunneling amplitude displays resonant peaks as a function of the modulation frequency; near the maxima it is exponentially larger than the RWA tunneling amplitude.