Bonn 2025 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

QI: Fachverband Quanteninformation

QI 21: Superconducting Qubits

QI 21.1: Invited Talk

Wednesday, March 12, 2025, 14:30–15:00, HS II

Mesoscopic physics challenges (in) superconducting quantum devices — •Ioan Pop — Karlsruhe Institute of Technology

Superconducting quantum bits, or qubits, are at the forefront of quantum computing research. Harnessing the low loss properties of superconductors and the nonlinearity of Josephson junctions, in recent processors tens of superconducting qubits can be engineered to exist in quantum superposition states and can be entangled. However, due to the innate complexity of solid-state physics, superconducting qubits still have to cope with various loss and decoherence mechanisms, certainly to the chagrin of quantum computing scientists, but also to the joy of mesoscopic physicists. I will discuss three mesoscopic physics phenomena which significantly complicate the task of engineering coherent superconducting hardware: ionizing radiation interactions with the device substrate, long lived two level systems which imprint a memory in the qubit's environment, and fluctuations in the transparency of aluminum oxide tunnel barriers which are at the heart of Josephson junctions.

Keywords: superconducting qubit; decoherence; hyperpolarization; Josephson junction