New Qubit Architecture is Easily Mass Produced

What if a different qubit architecture enabled easier manufacturing of quantum computer building blocks with no hit to performance?

The U.S. Department of Energy’s (DOE) Brookhaven National Laboratory researchers assert that a type of qubit whose architecture is more amenable to mass production performs comparably to existing qubits.

Recently, scientists are focusing on increasing the amount of time qubits retain quantum information. This is called coherence and is closely linked to the quality of a qubit’s junction. That focus is specifically on superconducting qubits with architecture that includes two superconducting layers separated by an insulator. This SIS junction, for superconductor-insulator-superconductor, has a drawback: reliable manufacturing is complex given the precision needed for the large-scale production of quantum computers.

A study from Brookhaven Lab demonstrates that qubits with constriction junctions (See B above) preform comparably to qubits with SIS junctions. Constriction junctions lay flat rather than stacking and fabricating constriction junctions is compatible with standard methods in semiconductor manufacturing facilities.

Superconducting constriction junctions are more linear than SIS junctions and are less ideal for qubit architectures. However, constriction junction nonlinearity can be tuned by selecting the superconducting material and design.