Towards characterizing TLS that impact superconducting qubits

Large variations in the energy relaxation time (T₁) of superconducting qubits makes it difficult to accurately evaluate and compare new qubit materials and fabrication processes, or to perform studies that require precise measurements of energy loss. To address this issue, we present techniques for characterizing qubit quality factors with voltages applied to electrodes in the vicinity of the qubit. A number of different experiments are reviewed which demonstrate how a TLS voltage electrode can be used to accelerate and improve learning about qubit coherence.