Magic state parity-checker with pre-distilled components

TL;DR

This paper introduces new protocols for magic state error suppression using non-Pauli parity checks with pre-distilled multiqubit resource states, enabling more efficient quantum gate implementation.

Contribution

It develops a novel two-step protocol combining pre-distillation of multiqubit states with non-Pauli parity measurements, improving efficiency over prior methods.

Findings

Achieves quadratic error reduction in magic state preparation.

Enables direct injection of single-qubit axial rotations.

Outperforms previous protocols like those of Bravyi and Haah.

Abstract

Magic states are eigenstates of non-Pauli operators. One way of suppressing errors present in magic states is to perform parity measurements in their non-Pauli eigenbasis and postselect on even parity. Here we develop new protocols based on non-Pauli parity checking, where the measurements are implemented with the aid of pre-distilled multiqubit resource states. This leads to a two step process: pre-distillation of multiqubit resource states, followed by implementation of the parity check. These protocols can prepare single-qubit magic states that enable direct injection of single-qubit axial rotations without subsequent gate-synthesis and its associated overhead. We show our protocols are more efficient than all previous comparable protocols with quadratic error reduction, including the protocols of Bravyi and Haah.