Title: Superconducting Quantum Circuits: Loss Mechanisms and Potential Mitigation Strategies

Speaker: Dr. Archan Banerjee, Yale University

Abstract: In the last twenty years, the emergence of quantum information science has intensified research toward building a quantum computer capable of performing computations beyond the capabilities of classical modern supercomputers. Superconducting qubits are among the most promising candidates in the race to build scalable and fault-tolerant quantum computers. However, functionalizing superconducting materials for applications in quantum information science necessarily requires exchanging information with the classical world through electromagnetic signals, creating decoherence channels for the devices. In this talk I will explore interplay between decoherence mechanism and material/ nanofabrication for superconducting quantum circuits. I will demonstrate how a combination of multimode resonator and participation ratio modeling can play a critical role in determining the contribution of individual loss channels affecting performance of superconducting quantum circuits. By selectively choosing several thin film/ substrate combinations, we show that the fabrication process and surface treatments can substantially impact loss factors of quantum circuits.