Research Question:
The question to be answered in this project is quite a fundamental one; ‘how do spins precess?’ but with a clear pathway for significant impact in spin-based quantum technologies. This might seem straight forward and even well understood, but our understanding of spin dynamics is largely restricted to steady states (i.e. long timescales). Therefore, understanding the temporal spin dynamics before stabilisation is paramount to realising any successful incorporation of these systems into quantum technologies [1]. Furthermore, for high quality factor magnetic materials, stabilisation happens over hundreds of nanoseconds and many quantum applications require operation rates within (or below) this timeframe. Thus, the discovery and understanding of unknown phenomena within this timeframe could open-up new functionality for quantum and classical technologies that require fast and low latency operations [2].

Proposed Research, its Importance, and engagement with current research:
The field of quantum magnonics focuses on controlling and reading out quanta of collective spin excitations in magnetically ordered systems. Control and manipulation of these quasi-particles, known as magnons, provides opportunities for advancing quantum technologies. For instance, magnon-photon hybridisation as a route to distribute quantum information has become an active topic of research. More recently, entanglement between a superconducting qubit and a magnetic sample has been demonstrated, showing that it is possible to detect a single quantum of magnetic excitation (a single magnon) within the magnet [3]. This entanglement-based single-shot detection of a single magnon using superconducting qubits was not only a giant leap towards magnet-based quantum sensing [4], but also demonstrates an active component of hybrid quantum systems that should find a wide range of applications in quantum technologies. In quantum magnonic devices there is a coupling—or coherent exchange of information—between photon and magnon modes [5]. This coupling, in addition to being able to directly couple to (and exchange information with) third party quantum components is being investigated for the up-conversion of microwave quantum information into optical signals that can be transferred over long distances [6]. The coherent conversion of microwave signals into optical photons could significantly expand our ability to process and communicate quantum states and it would be imperative for quantum-noise-limited microwave electronic components. Perhaps even more exciting, conversion of said information remains one of the key hurdles to creating a quantum internet—which would enable sharing quantum information between quantum computers as we do with current technology [2,7].

Methodology:
This project will draw inspiration from recent efforts in the field of electron spins in semiconductors where research has explored how to shape pulses to take a single spin from a quantum state into another in a controlled fashion, and to control and manipulate several distinct spins in a crystal lattice, for example, to build quantum registers. Therefore, expanding this is imperative to successfully interface spintronic technologies with quantum circuits. For instance, high-amplitude excitations can lead to non-linear dynamics which is analogous to spin qubits but yet to be investigated in magnonic systems. This is, however, crucial for developing effective quantum spintronic technology for information exchange.