Unruh radiation produced by a uniformly accelerating charged particle in thermal random motions

In this study, we investigate the signature of the Unruh effect in quantum radiation from an accelerated charged particle interacting with vacuum fluctuations. Because a charged particle in uniformly accelerated motion exhibits thermal random motion around the classical trajectory because of the Unruh effect, its quantum radiation might be termed Unruh radiation. We show that the energy flux of the quantum radiation is negative and that its amplitude is smaller than the classical Larmor radiation by a factor of $a/m$, where $a$ is the acceleration and $m$ is the mass of the particle. The total radiation flux of the classical Larmor radiation and the quantum radiation is positive; therefore, the quantum radiation appears to suppress the total radiation. Interestingly, the results are consistent with the prediction for the quantum correction to classical Larmor radiation, which were obtained using a different approach.