Measurement-free gadgets & classical logic in ion trap quantum computers
In many emerging quantum processors, notably ion‑trap and neutral‑atom platforms, the ability to perform fast, reliable mid‑circuit measurements is still limited. This limitation poses a significant barrier to the practical implementation of fault‑tolerant (FT) primitives such as quantum error‑correction (QEC) and magic‑state distillation (MSD), both of which traditionally rely on measurement and classical feed‑forward. In this talk we discuss recent constructions of measurement‑free gadgets that replace classical measurement with coherent quantum feedback, enabling full circuit-level fault‑tolerant operation of low‑distance CSS codes and deterministic MSD. In order to scale up these gadgets, we develop a notion of realizing classical logic, as required for operation of efficient FT decoders, through quantum gates on the auxiliary system.