Particle radiation produced by accelerated systems and their analogy with damped oscillators

Abstract

The Unruh effect predicts how uniformly accelerated observers will perceive a change in the vacuum state. This shows that the concept of particle number depends on the acceleration of the reference frame. Although this is a result of quantum field theory, its experimental verification is still questioned, mainly due to the high accelerations required. In this work we study a quantum oscillator with only one complex coordinate and a damping term acting as perturbation, which has all the characteristics of the Unruh effect in second quantization for an accelerated observer. The Bogoliubov transformation connecting the two different vacuum states is obtained. This leads to an explicit formula for the particle occupation number as a function of energy and acceleration. Furthermore, it is shown that our analogue system contains an effective temperature that depends on the observer's sudden acceleration, seen as a friction force. The purpose of this work is to demonstrate that quanta production (particles or energy packets) is inevitable under the premises of quantum field theory.