  The Nitrogen-vacancy (NV) center in diamond plays important roles in emerging
quantum technologies. Currently available methods to fabricate the NV center
often involve complex processes such as N implantation. By contrast, in a
diamond-like compound C3BN, creating a boron (B) vacancy immediately leads to
an NV center analog. We use the strongly constrained and appropriately normed
(SCAN) semilocal density functional - this functional leads to nearly the same
zero-phonon line (ZPL) energy as the experiment and as obtained from the more
time-consuming hybrid density functional calculations - to explore the
potential of this NV center analog as a novel spin qubit for applications in
quantum information processing. We show that the NV center analog in C3BN
possesses many similar properties to the NV center in diamond including a wide
band gap, weak spin-orbit coupling, an energetically stable negatively charged
state, a highly localized spin density, a paramagnetic triplet ground state,
and strong hyperfine interactions, which are the properties that make the NV
center in diamond stand out as a suitable quantum bit (qubit). We predict the
NV center analog in C3BN to exhibit two ZPL energies that correspond to longer
wavelengths close to the ideal telecommunication band for quantum
communications. C3BN studied here represents only one example of A3XY (A: group
IV element; X/Y: group III/V elements) compounds. We expect many other
compounds of this family to have similar NV center analogs with a wide range of
ZPL energies and functional properties, promising to be new hosts of qubits for
quantum technology applications. Furthermore, A3XY compounds often contain
group IV elements such as silicon and germanium, so they are compatible with
the sophisticated semiconductor processing techniques. Our work opens up ample
opportunities towards scalable qubit host materials and novel quantum devices.
