Talks

Continuous variable (CV) systems play an important role in quantum foundations and quantum information processing, especially because of their quantum optical realization. Gaussian states of CV systems, on the one hand have non-trivial quantum properties, and on the other hand, can be realized in the laboratory.  There are non-Gaussian states which can be obtained from Gaussian states via physically realizable operations and these too can be useful in enhancing  non-classicality and improving the performance of quantum information processing protocols.  In the talk, I will  introduce CV systems and their Gaussian and non-Gaussian states. The violation of Bell-type inequalities using CV systems will be discussed. Quantum key distribution protocols and quantum teleportation schemes using Gaussian and non-Gaussian states will also be taken up. 

In this talk I will discuss the energy probability density function of an evaporating near-extremal charged black hole. At sufficiently low energies, such black holes experience large quantum metric fluctuations in the $AdS_{2}$ throat which are governed by a Schwarzian action. These fluctuations modify Hawking evaporation rates, and therefore also affect how the black hole state evolves over time. In previous work on Schwarzian-corrected Hawking radiation, the black hole was taken to be in the microcanonical or canonical ensemble [arXiv:2411.03447]. However, we find that an initially fixed-energy or fixed-temperature state does not remain so in the regime where Schwarzian corrections are important. We consider three decay channels: the emission of massless scalars, photons, and entangled pairs of photons in angular momentum singlet states. In each of the three cases, we find that in the very low energy, quantum dominated regime, the probability distribution of the black hole energy level occupation tends toward a particular attractor function that effectively depends on only one combination of time and energy. This function is independent of the initial state and gives new predictions for the energy fluxes and Hawking emission spectra of near-extremal charged black holes.