Środowiskowe Seminarium z Informacji i Technologii Kwantowych

The Unruh effect is a fundamental result of the application of quantum field theory to curved spacetimes. It states that accelerated observers experience the vacuum as a thermal state of particles at a temperature proportional to the acceleration. The subject of the Unruh effect has received renewed interest in the last decade, as the quantum optics community have begun to realize that the Unruh transformation is an example of a basic and well-known class of Gaussian unitary operations known as two-mode squeezing operations. Two mode squeezed states, are entangled states that are routinely generated by parametric-down conversion in non-linear crystals. It has been the focus of the newly emerging field of Relativistic Quantum Information theory to characterize how this Unruh squeezing operator in conjunction with the existence of event horizons can degrade the entanglement that accelerated observers see. However, when looking at entanglement seen between accelerated and inertial observers, previous studies had misinterpreted the dependence of initial state with that of the acceleration. This misinterpretation can be traced back to the use of global field modes like Unruh modes, where the inability to control the size and location of their observation left the physical interpretation of these models unclear. In this talk I will discuss a recent series of works I have done in collaboration, which re-investigates the problem of entanglement degradation due to acceleration in a localized setting. I will discuss how the approach enables one for the first time to solve the acceleration degradation problem and leads to new insights into the degradation process.