How can we cope with noisy quantum computers?

In recent years, quantum computation has become a hot word in the scientific world and has gradually enterered public view. While quantum computer prototypes have been developed with amazing speed, one should never ignore that they are formed with imperfect controls. Quantum error correction offers a solution: each ‘logical qubit’ is really stored using a group of physical qubits in a specially protected code state – if one of the physical qubits becomes corrupt, it is possible to restore it using the collective information in the others.

Presently there are several different multi-university international collaborations aimed at achieving the first logical qubit. But this is a challenging task, and the different hardware platforms that are being used have radically different properties and timescales.

In the present paper, we introduce a new measure for the quality of a quantum memory  which all researchers can use regardless of their platform of choice. We list four crucial milestones which pave the path from present day technology towards a fully functioning logical qubit. We show how experiments can be designed using exact simulations. Various small code are also implemented.

The paper can be found in here.