  The magnetic stability of oxygen deficiency centers on the surface of
{\alpha}-quartz is investigated with first- principles calculations to
understand their role in contributing to magnetic flux noise in superconducting
qubits (SQs) and superconducting quantum interference devices (SQUIDs)
fabricated on amorphous silica substrates. Magnetic defects on the substrate
are likely responsible for some of the 1/f noise that plagues these systems.
Dangling-bonds associated with three-coordinated Si atoms allow electron
density transfer between spin up and down channels, resulting in low energy
magnetic states. Such under-coordinated Si defects are common in both
stoichiometric and oxygen deficient silica and quartz and are a probable source
of magnetic flux fluctuations in SQs and SQUIDs.
