Qiskit Quantum Seminar

Currently Playing: Protecting Superconducting Qubits from Environmental Poisoning with Britton Plourde

Qiskit Seminar Series: Protecting Superconducting Qubits from Environmental Poisoning Your formal invite to weekly Qiskit videos ► https://ibm.biz/q-subscribe Speaker: Britton Plourde Host: Zlatko Minev, PhD. Abstract: Superconducting circuits are an attractive system for forming qubits in a quantum computer because of the natural energy gap to excitations in the superconductor. However, experimentally it is observed that superconducting qubits have excitations above the superconducting ground state, known as quasiparticles, at a density that is many orders of magnitude above the expected equilibrium level. These quasiparticles are dissipative and can directly impact qubit coherence; in some cases, quasiparticle poisoning bursts can lead to correlated errors between qubits across an array, a process that is fatal to quantum error correction schemes. Quasiparticles can be generated by a range of energy-deposition sources, including photons from the qubit environment with energy above the superconducting gap, or the impact of high-energy particles from background radioactivity or cosmic ray muons. Following an overview of these various quasiparticle poisoning mechanisms, I will describe two recent experiments: one studying absorption of photons by spurious antenna modes of qubit structures, the other measuring correlated phonon-mediated quasiparticle poisoning in multiqubit chips in the aftermath of particle impacts. I will discuss strategies for mitigating these poisoning effects for the implementation of future fault-tolerant quantum processors. Bio: Britton Plourde received a Ph.D. in physics from the University of Illinois at Urbana-Champaign in 2000 studying vortex dynamics in superconductors. From 2000 to 2004, he was a postdoctoral scholar at the University of California, Berkeley where he worked on experiments with superconducting flux qubits. In 2005, he joined the Department of Physics at Syracuse University where he runs a low-temperature research lab investigating various aspects of superconducting circuits for quantum information processing. His research efforts have been supported by the Army Research Office, IARPA, DARPA, the Air Force Office of Scientific Research, and the National Science Foundation. Prof. Plourde received a CAREER award from the NSF in 2006 and an IBM Faculty Award in 2011. From 2013-2019 he was the Editor-in-Chief for the IEEE Transactions on Applied Superconductivity, and from 2021-2022 he was the Editor-in-Chief for the IEEE Transactions on Quantum Engineering. -- The Qiskit Seminar Series is a deep dive into various academic and research topics within the quantum community. It will feature community members and leaders every Friday, 12 PM EDT.