Speaker
Description
Well-known axion models, such as the DFSZ model, predict an interaction between axions and electron spins. This interaction can excite magnons—the quanta of collective spin excitations—in ferromagnetic materials like Yttrium Iron Garnet (YIG). Detecting axion-induced magnons provides a pathway to probing axion parameter space in the μeV mass range.
Traditional axion haloscope experiments rely on linear amplifiers to measure both phase and amplitude of the haloscope, but these approaches face fundamental limitations imposed by the Standard Quantum Limit (SQL) due to zero-point fluctuations. An alternative approach is to measure only the occupation number (amplitude) of haloscope rather than both the phase and the amplitude, which would be immune to zero-point fluctuations. One promising method to achieve this is through the dispersive interaction between a superconducting qubit and magnon.
In this presentation, we evaluate the sensitivity of different protocols of performing magnon number measurement (magnon counting) that leverage dispersive interaction between qubit and magnon. Using a model qubit-magnon hybrid setup, we identify key trade-offs in various magnon counting protocols and explore optimization strategies to improve axion detection efficiency across a broad mass range. These strategies will guide our development of a qubit-magnon hybrid system, which we plan to construct in the future to explore the axion parameter space in the μeV mass range.
