Fig. 1: All-nitride C-shunt flux qubit consisting of epitaxially grown NbN/AlN/NbN Josephson junctions on Si substrate.
From: Enhanced coherence of all-nitride superconducting qubits epitaxially grown on silicon substrate
a a photograph of the qubit chip mounted into the sample package, b Laser scanning microscope image of the capacitively shunted flux qubit coupled to a half-wavelength (\(\lambda\)/2) CPW resonator made of NbN/TiN on a Si substrate. The inset shows a magnified image of a false-colored flux qubit structure with three NbN/AlN/NbN Josephson junctions (marked as JJ1, JJ2, and JJ3). c Scanning electron microscopy images corresponding to the three JJs taken after the qubit measurements. d The thickness profile of qubit taken from the laser scanning microscope system. The displayed scales are in \(\mu\)m. e Cross-sectional schematics of the part indicated by the blue star and dashed line in b. The JJ parts are marked by the orange dotted ellipses.
