Dispersive-induced magnon blockade with a superconducting qubit

We investigate the magnon blockade effect in a quantum magnonic system operating in the strong dispersive regime, where a superconducting qubit interacts dispersively with a magnonic mode in a yttrium-iron-garnet sphere. By solving the quantum master equation, we demonstrate that the magnon blockade, characterized by the second-order correlation function <inline-formula><math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="c:\heptemp\HML50727241.png" baseline="-3.5" display="inline" id="mathml_M1" overflow="scroll"><mml:mrow class="MJX-TeXAtom-ORD"> <mml:msup><mml:mi>g</mml:mi><mml:mrow class="MJX-TeXAtom-ORD"><mml:mo stretchy="false">(</mml:mo><mml:mn>2</mml:mn><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:msup><mml:mo stretchy="false">(</mml:mo><mml:mn>0</mml:mn><mml:mo stretchy="false">)</mml:mo><mml:mo stretchy="false">&#x2192;</mml:mo><mml:mn>0.04</mml:mn></mml:mrow></math></inline-formula>, emerges under optimal dispersive coupling and driving detuning. The mechanism is attributed to suppressed two-magnon transitions as a result of qubit-induced anharmonicity. Notably, our study identifies the critical role of dispersive interaction strength and environmental temperature, showing that magnon blockade remains observable under experimentally achievable cryogenic conditions. This work extends the magnon blockade effect into the dispersive regime, offering a robust platform for single-magnon manipulation and advancing applications in quantum sensing and information processing.