Quantum Optical Heating in Sonoluminescence Experiments

TL;DR

This paper proposes that in sonoluminescence, rapid bubble deformations generate inhomogeneous electric fields that couple atomic motion to electronic states, leading to high heating rates and explaining the observed high temperatures.

Contribution

It introduces a quantum optical heating mechanism driven by inhomogeneous electric fields during bubble collapse, offering a new explanation for sonoluminescence heating.

Findings

Inhomogeneous electric fields can induce atomic heating during bubble collapse.

Coupling of atomic motion to electronic states results in high heating rates.

The proposed mechanism explains the high temperatures observed in sonoluminescence.

Abstract

Sonoluminescence occurs when tiny bubbles rilled with noble gas atoms are driven by a sound wave. Each cycle of the driving field is accompanied by a collapse phase in which the bubble radius decreases rapidly until a short but very strong light flash is emitted. The spectrum of the light corresponds to very high temperatures and hints at the presence of a hot plasma core. While everyone accepts that the effect is real, the main energy focussing mechanism is highly controversial. Here we suggest that the heating of the bubble might be due to a weak but highly inhomogeneous electric field as it occurs during rapid bubble deformations [A. Kurcz et al. (submitted)]. It is shown that such a field couples the quantised motion of the atoms to their electronic states, thereby resulting in very high heating rates.