International Business Machines Corporation
Transmon qubits with self defined junctions

Abstract:

A method of making a Josephson junction in a superconducting qubit includes providing a substrate having a convex structure with a first face and a second face meeting at an edge; depositing a first layer of superconducting material on the first face; oxidizing the first layer to form a layer of oxide material on a surface of the first layer; and depositing a second layer of the superconducting material on the second face. A portion of the second layer is in contact with a portion of the layer of oxide material at or in the vicinity of the edge such that the portion of the layer of oxide material is sandwiched between a portion of the first layer and the portion of the second layer to define a Josephson junction at or in the vicinity of the edge.