Over the past decade, qubits encoded in superconducting circuits have emerged as a leading platform for quantum information processing, resulting in a rapidly expanding and thriving research field. However, present-day superconducting quantum processors are still highly susceptible to the effects of environmental noise, which degrades their computational performance and limits applications. As a result, developing next-generation superconducting qubits with improved protection is a major research focus to accelerate the path to a fault-tolerant quantum computer.
In this talk, I will introduce our approach for protecting quantum information in superconducting circuits, which relies on quantum material Josephson junction realized in superconductor-semiconductor hybrid structures [1,2]. First, I will describe how such hybrid quantum materials when placed in contact with superconductors can give rise to an exotic charge-4e supercurrent and discuss approaches for experimentally detecting this coherent transport of “pairs of Cooper-pairs“ . Second, I will present resulting insights in how the charge-4e supercurrent can be employed to create a protected “0-Pi“ superconducting qubit in arrays of Josephson junctions and discuss how the Josephson junction arrays can be theoretically modeled with effective spin models. Finally, I will compare the “0-Pi“ protected superconducting qubits to an alternative approach based on topological wavefunctions, the Majorana zero modes [4,5], and discuss how quantum material Josephson junctions can provide a new avenue for bosonic and femionic quantum simulation.
Tuesday, May 2, 2023 at 3:30pm to 4:30pm