Performing multi-qubit quantum logic gates using asymmetric bipolar bias pulses

Abstract

In a general aspect, a method of performing multi-qubit quantum logic gates in a superconducting quantum computing system including a first tunable-frequency qubit device and a second qubit device is presented. In some instances, the method includes parking a transition frequency of the first tunable-frequency qubit device at a parking frequency that is offset from a sweet spot by applying to the first tunable-frequency qubit device, a bias field with a parking amplitude corresponding to the parking frequency; and applying a two-qubit quantum logic gate to a pair of qubits defined by the first and second qubit devices by applying an asymmetric bipolar bias pulse to the first tunable-frequency qubit device relative to the parking amplitude. The asymmetric bipolar bias pulse includes first and second bias pulse components having respective gate-activating amplitudes that correspond to a gate-activating frequency.