Topology and Superconductivity: Uncovering the Path Towards Fault-Tolerant Quantum Computing*

Quantum computing has emerged as a promising new technology capable of tackling a certain class of problems that are intractable with classical digital computers. Quantum processors use quantum bits (qubits) to represent and process information. Compared to classical bits qubits can provide enormous computational advantage. However, conventional qubits are fragile and prone to errors, requiring the implementation of intensive quantum error correction. Building scalable quantum error correction architectures is a formidable technological challenge and remains the main obstacle to the realization of fault-tolerant quantum computers. In this talk, I will discuss how the realization of a new phase of matter called topological superconductivity can be used to build qubits that can store information nonlocally and are, therefore, robust against smooth local perturbations. These error-protected qubits, known as topological qubits, could overcome the quantum error correction implementation challenges and render a path towards fault-tolerant quantum computing. I will address recently proposed platforms for realizing, manipulating, and detecting the topological superconducting state and corresponding topological qubits, with a particular focus on planar Josephson junctions. The signatures of the topological superconducting state in measurable physical quantities and their use for revealing its fundamental properties will also be discussed.