Curator's Take
This fascinating research bridges high-energy particle physics and quantum information theory by treating top quark-antiquark pairs as quantum entangled systems that can be studied using tools from quantum computing. The extremely short lifetime of top quarks means they decay before their quantum correlations can be disrupted, creating a natural laboratory for studying quantum entanglement in one of the most energetic environments in nature. The finding that quantum teleportation protocols remain viable even under noisy conditions in these high-energy processes suggests that particle accelerators could serve as unexpected testbeds for quantum information protocols. This work opens intriguing possibilities for using existing particle physics infrastructure to explore quantum phenomena and potentially develop new quantum sensing techniques for fundamental physics research.
— Mark Eatherly
Summary
The measurement of top-quark spin correlations provides a key tool for probing its interactions with high precision. Owing to its extremely short lifetime ($τ\sim 10^{-25}$ s), the top quark preserves its spin polarization information, making the $t\bar{t}$ system an ideal framework for investigating quantum correlations in high-energy physics. In this work, we analyze quantum correlations in $t\bar{t}$ pairs produced in QCD using several quantum information-theoretic measures, including Bell nonlocality, quantum steering, concurrence, and geometric quantum discord. Their dependence on kinematic variables is examined in both the $gg \to t\bar{t}$ and $q\bar{q} \to t\bar{t}$ channels, with convergence toward the $gg \to t\bar{t}$ dominated regime in the ultra-relativistic limit ($β= 1$). We also investigate the effect of three effective decoherence channels (AD, PD, and PF). The AD and PD channels lead to a monotonic degradation of correlations as the decoherence parameter $p$ increases, while the PF channel exhibits a symmetric behavior around $p=1/2$. The impact of these channels on quantum teleportation is analyzed, showing that it remains above the classical threshold of $2/3$ even in the presence of noise. These results indicate that certain quantum resources can persist despite decoherence, opening new perspectives at the interface of quantum information and particle physics.