Magnetic quantum dots as novel quantum information platform

A nanoscale magnet possesses a discrete magnon spectrum, analogous to a zero-dimensional quantum dot. The individual magnon modes interact through scattering processes that exhibit features distinctly different from their macro-/mesoscopic counterparts. We demonstrate that such nonlinear processes can be mapped to controllable single qubits, positioning magnetic quantum dots as a promising platform for quantum computation and simulation due to their tunability, energy efficiency, and scalability. We discuss spin engineering techniques for controlling magnon scattering and functionalizing magnetic quantum dots for quantum information processing. Additionally, we examine methods for multi-qubit gate operations, including the use of dipolar and exchange interaction, as well as hybrid systems. Finally, we explore the potential of up-scaled magnon populations for realizing qudits and analog quantum simulators.