Schrödinger first introduced the term “Verschränkung” (entanglement) to describe the peculiar correlations between two or more quantum particles (Schrödinger, 1935, p. 555). He argued that this phenomenon is “the characteristic trait of quantum mechanics, the one that enforces its entire departure from classical lines of thought.”
The first part of the talk examines how entanglement appears across diverse physical systems, including those at very high energies. Examples include claims that entanglement in high-energy photons could aid cancer diagnostics, entanglement-related effects in neutrino and K-meson oscillations, and the prospect of using a single neutron in a gravitational field for quantum computing.
The second part addresses the separability problem—determining whether a quantum state is entangled—which is known to be NP-hard. In particular, we show that PPT entanglement is not uncommon, but difficult to detect. Since uncontrolled environmental interactions introduce errors that challenge the reliability of entanglement-based quantum technologies, we focus on entanglement distillation: converting multiple copies of weakly entangled states into fewer, nearly maximally entangled ones. We present a new distillation protocol, FIMAX, that outperforms existing methods.
*)"Low-Fidelity Entanglement Distillation with FIMAX", Ch. Popp, T. Sutter and B. C. Hiesmayr,
International Journal of Quantum Information 23, 2550017 (2025)
*)"Probing arbitrary polarized photon pairs undergoing double Compton scatterings by a dedicated MC simulator validated with experimental data", M. Bala, W. Krzemien, B.C. Hiesmayr, J. Baran, K. Dulski, K. Klimaszewski, L. Raczynski, R. Y. Shopa, W. Wislicki, The European Physical Journal C, 85:1115, 2025.