Extensible Architecture for Superconducting Quantum Computing

Abstract

Quantum computing architectures with ten or more quantum bits (qubits) have been implemented using trapped ions and superconducting devices. The next milestone in the quest for a quantum computer is the realization of quantum error correction codes. Such codes will require a large number of qubits that must be controlled and measured by means of classical electronics. This scaling up leads to a number of problems and sources of error that must be accounted for in order to have an operational system.

One architectural aspect requiring immediate attention is the realization of a suitable interconnect between the quantum and classical hardware. Our proposed solution to this wiring problem is the quantum socket, a three-dimensional wiring method for qubits with superior performance as compared to two-dimensional methods based on wire bonding. The quantum socket also provides a means to counteract another scaling problem, the coupling of qubits to unwanted cavity modes resulting in coherent leakage error. By following our proposed wiring methodologies, half-wave fencing or antinode pinning, we show how the error due to leakage can be mitigated to orders of magnitude below current state-of-the-art error probabilities.