Pure dephasing of magnonic quantum states

Abstract

For a wide range of nonclassical magnonic states that have been proposed and demonstrated recently, a new time scale besides the magnon lifetime - the magnon dephasing time - becomes important, but this time scale is rarely studied. Considering exchange interaction and spin-phonon coupling, we evaluate the pure magnon dephasing time and find it to be smaller than the magnon lifetime at temperatures of a few Kelvins. By examining a magnonic cat state as an example, we show how pure dephasing of magnons destroys and limits the survival of quantum superpositions. Thus it will be critical to perform quantum operations within the pure dephasing time. We further derive the master equation for the density matrix describing such magnonic quantum states taking into account the role of pure dephasing, whose methodology can be generalized to include additional dephasing channels that experiments are likely to encounter in the future. Our findings enable one to design and manipulate robust quantum states of magnons for information processing.

6 pages, 3 figures

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Cited by in corpus (9)

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• Master equation approach to magnon relaxation and dephasing
• Protocol for generating an arbitrary quantum state of the magnetization in cavity magnonics
• Fate of entanglement in magnetism under Lindbladian or non-Markovian dynamics and conditions for their transition to Landau-Lifshitz-Gilbert classical dynamics
• High dynamic-range quantum sensing of magnons and their dynamics using a superconducting qubit
• Quantum Sensing of Antiferromagnetic Magnon Two-Mode Squeezed Vacuum
• Non-Hermitian Casimir effect of magnons
• Phonon- and magnon-mediated decoherence of a magnonic qubit