Fluctuations-Induced Quantum Radiation and Reaction from an Atom in a Squeezed Quantum Field
arXiv:2303.06831 · doi:10.3390/physics5020040
Abstract
In this third of a series on quantum radiation, we explore the feasibility of using the memories kept in a quantum field to decipher certain information about the early universe. As a model study, we let a massless quantum field be subjected to a parametric process for a finite time interval such that the mode frequency of the field transits from one constant value to another. This configuration mimics a statically-bounded universe, but not a continuously evolving one. The field squeezed by this process should contain information of the process itself. If an atom is coupled to the field after the parametric process, its response will depend on the squeezing, and any quantum radiation emitted by the atom will carry this information away so that an observer at a much later time may still identify it. Our analyses show that 1) a remote observer cannot measure the generated squeezing via the radiation energy flux from the atom because the net radiation energy flux is canceled. However, 2) there is a chance to identify squeezing by measuring the constant radiation energy density at late times. The only restriction is that this energy density is of the near-field nature. The second part of this paper focuses on 3) the dependence of squeezing on the functional form of the parametric process. Via several examples we demonstrate that the behavior of squeezing reflect essential properties of the parametric process. In fact, striking features may show up in complicated processes involving various scales. These analyses allow us to establish the connection between properties of a squeezed quantum field and the parametric process which does the squeezing. Therefore, 4) one can construct templates to reconstitute the unknown parametric processes from the data of measurable quantities subjected to squeezing. In a sequel paper these results will be applied to a study of quantum radiations in cosmology.
arXiv comment10 pages, 43 figures
References in corpus (11)
- The critical manifold of the Lorentz-Dirac equation
- Stochastic Theory of Relativistic Particles Moving in a Quantum Field: II. Scalar Abraham-Lorentz-Dirac-Langevin Equation, Radiation Reaction and Vacuum Fluctuations
- Squeezed Vacua and the Quantum Statistics of Cosmological Particle Creation
- Quantum thermodynamics from the nonequilibrium dynamics of open systems: energy, heat capacity and the third law
- Uniformly Accelerated Charge in a Quantum Field: From Radiation Reaction to Unruh Effect
- No intrinsic decoherence of inflationary cosmological perturbations
- Atom-Field Interaction: From Vacuum Fluctuations to Quantum Radiation and Quantum Dissipation / Radiation Reaction
- NonMarkovian Abraham--Lorentz--Dirac Equation: Radiation Reaction without Pathology
- Quantum Parametric Oscillator Heat Engines in Squeezed Thermal Baths: Foundational Theoretical Issues
- Dynamical Response of an Unruh-DeWitt Detector in a Quantum Field over the History of the Universe
- Quantum Radiation and Dissipation in Relation to Classical Radiation and Radiation Reaction