QuKiT · Quantum bits with Kitaev Transmons

Most mainstream approaches to quantum computing are limited by short qubit coherence times at a level that impedes the implementation of quantum error correction. A truly viable approach to achieving fault tolerant computation, and solving socially relevant problems, thus requires inherently better qubits. In this project, we propose to realize a new type of qubit based on a hybrid between superconductors and semiconductors – two leading platforms at this time. The qubit will be engineered such that the states of this qubit are immune to most decoherence mechanisms currently limiting mainstream implementations of a quantum computer. We plan to achieve this by encoding quantum information in a topologically protected system. Such a system will be engineered by creating arrays of quantum dots with superconducting coupling (the so called Kitaev chain) in two-dimensional electron gases (2DEGs). Embedding the Kitaev chain in a transmon architecture will allow us to perform single-qubit and two-qubit operations using well-established control-techniques from the field of superconducting qubits. Combining these control elements with record long qubit coherence times we expect high gate fidelities beyond the state of the art. The choice of using the 2DEG platform naturally lends itself to scalability in the longer term, and we plan to develop a clear roadmap for future scaling within the course of the project.