About the talk

Superconducting qubits and semiconducting qubits are two leading solid-state platforms for quantum computation, each coming with distinct strengths and challenges. Hybrid structures made of both semiconductors and superconductors aim to combine the best features of both platforms. One such hybrid structure is the Andreev spin qubit, which hosts a microscopic, fermionic spin degree of freedom inside a Josephson weak link. The key feature is the spin-dependent supercurrent – this physics enables long-range, quantum coherent interactions between spins despite their microscopic sizes. In this talk, I will first introduce Andreev spin qubits and what makes them unique. I will then describe our experiments to better understand coherence of Andreev spins hosted in InAs nanowires. Finally, I will outline the unique quantum hardware opportunities that Andreev spins offer, as well as the key experimental challenges to achieving them.  

About the speaker

Valla received his PhD in Physics in the group of Pablo Jarillo-Herrero at the Massachusetts Institute of Technology in 2018. There he worked on electronic and quantum transport in topological insulator materials, including discovery superconductor and topological insulator states in monolayer tungsten ditelluride. He also contributed to the project that discovered superconductivity and correlated insulator states in magic angle twisted bilayer graphene. He then joined the group of Michel Devoret at Yale University as the post-doctoral associate on the teams researching the physics of Andreev bound states in superconductor-semiconductor quantum devices, where the Andreev spin qubit was first demonstrated. In 2022 he joined the faculty of the School of Applied and Engineering Physics at Cornell University, where he is building a lab researching the basic and applied physics of quantum materials, quantum control, superconducting quantum circuits, and their intersections.