Error detection without post-selection in adaptive quantum circuits

Abstract

Current quantum computers are limited by errors, but have not yet achieved the scale required to benefit from active error correction in large computations. We show how simulations of open quantum systems can benefit from error detection. In particular, we use Quantinuum's H2 quantum computer to perform logical simulations of a non-equilibrium phase transition using the [[4,2,2]] code. Importantly, by converting detected errors into random resets, which are an intended part of the dissipative quantum dynamics being studied, we avoid any post-selection in our simulations, thereby eliminating the exponential cost typically associated with error detection. The encoded simulations perform near break-even with unencoded simulations at short times.