Phonon- and magnon-mediated decoherence of a magnonic qubit

Abstract

We investigate the decoherence of magnonic qubits in small ferromagnetic insulators and compute the relaxation and dephasing rates due to magnon-phonon and magnon-magnon interactions. We combine a Bloch--Redfield description with Keldysh non-equilibrium field theory to find explicit expressions for the rates. For a quadratic dispersion and assuming a uniform mode defines the qubit, we find that decay into two phonons is the only allowed relaxation process at zero temperature. The low resonance frequency and heavy unit cell strongly suppress this process in yttrium-iron-garnet. We also find that the dephasing rate scales with the inverse of size and damping of the magnet, and could become large for small and clean magnets. Our calculation thus provides additional insight into the viability of magnon-based quantum devices.

arXiv comment14 pages, 5 figures

References in corpus (46)

• Supplementary information for "Quantum supremacy using a programmable superconducting processor"
• Quantum Computing
• Superconducting Qubits: Current State of Play
• Trapped-Ion Quantum Computing: Progress and Challenges
• Strongly coupled magnons and cavity microwave photons
• High cooperativity in coupled microwave resonator ferrimagnetic insulator hybrids
• Semiconductor Spin Qubits
• Magnon-photon-phonon entanglement in cavity magnomechanics
• Quantum magnonics: when magnon spintronics meets quantum information science
• Quantum computing with neutral atoms
• Entanglement-based single-shot detection of a single magnon with a superconducting qubit
• Cavity Magnonics
• Semiconductor Qubits In Practice
• An Introduction to Spin Wave Computing
• Squeezed states of magnons and phonons in cavity magnomechanics
• Keldysh approach for non-equilibrium phase transitions in quantum optics: beyond the Dicke model in optical cavities
• Ultra-High Cooperativity Interactions between Magnons and Resonant Photons in a YIG sphere
• Quantum entanglement between two magnon modes via Kerr nonlinearity
• Multi-level quantum description of decoherence in superconducting qubits
• Dissipation-based Quantum Sensing of Magnons with a Superconducting Qubit
• Quantum control of a single magnon in a macroscopic spin system
• Nonequilibrium many-body steady states via Keldysh formalism
• Spin Insulatronics
• Magnon-phonon interactions in magnetic insulators
• Magneto-elastic modes and lifetime of magnons in thin yttrium-iron garnet films
• Low damping and microstructural perfection of sub-40nm-thin yttrium iron garnet films grown by liquid phase epitaxy
• Beyond-classical computation in quantum simulation
• Microwave magnon damping in YIG films at millikelvin temperatures
• Microscopic spin-wave theory for yttrium-iron garnet films
• Gilbert damping of magnetostatic modes in a yttrium iron garnet sphere
• Tuning entanglement by squeezing magnons in anisotropic magnets
• Reversal of nanomagnets by propagating magnons in ferrimagnetic yttrium iron garnet enabling nonvolatile magnon memory
• Magnon qubit on double Bose-Einstein condensate
• Magnon antibunching in a nanomagnet
• Classical analog of qubit logic based on a magnon Bose-Einstein condensate
• Magnons at low excitations: Observation of incoherent coupling to a bath of two-level-systems
• Magnon blockade in magnon-qubit systems
• Quantum Control of Spin Qubits Using Nanomagnets
• Master equation approach to magnon relaxation and dephasing
• Pure dephasing of magnonic quantum states
• Cavity magnonics with easy-axis ferromagnet: Critically enhanced magnon squeezing and light-matter interaction
• Stabilizing a single-magnon state by optimizing magnon blockade
• Spin transport in an electrically-driven magnon gas near Bose-Einstein condensation: Hartree-Fock-Keldysh theory
• High dynamic-range quantum sensing of magnons and their dynamics using a superconducting qubit
• Magnon-assisted magnetization reversal of Ni81Fe19 nanostripes on Y3Fe5O12 with different interfaces
• Magnon-mediated quantum gates for superconducting qubits