Shih-Yuin Lin, National Changhua University of Education
We calculate quantum radiated energy flux emitted by an Unruh DeWitt (UD) detector, with the internal harmonic oscillator coupled to a massless scalar field, in linear oscillatory motion in (3+1) dimensional Minkowski space. Our results show that, when the averaged proper acceleration is sufficiently low, the signal of the Unruh effect can be greatly suppressed by quantum interference. In contrast, the Unruh-like effect can be pronounced in quantum radiation in the highly non-equilibrium regime with high averaged acceleration and short oscillatory cycle. While the averaged radiated energy flux over a cycle is always positive as guaranteed by the quantum inequalities, an observer at a fixed angle may see short periods of negative radiated energy flux in each cycle of motion, which indicates that the radiation is squeezed. We analyze the asymptotic state of the field to examine this.