Ultrastrong magnon-photon coupling and entanglement in superconductor/ferromagnet nanostructures

Abstract

Ultrastrong light-matter coupling opens exciting possibilities to generate squeezed quantum states and entanglement. Here we propose a way to achieve this regime in superconducting hybrid nanostructures with ferromagnetic interlayers. Strong confinement of electromagnetic field between superconducting plates is found to result in the existence of magnon-polariton modes with ultrastrong magnon-photon coupling, ultra-high cooperativity and very large group velocities. These modes provide a numerically accurate explanation of recent experiments and have intriguing quantum properties. The magnon-polariton quantum vacuum consists of the squeezed magnon and photon states with the degree of squeezing controlled in wide limits by the external magnetic field. The ground state population of virtual photons and magnons is shown to be very large which can be used for generating correlated magnon and photon pairs. Excited states of magnon-polaritons contain bipartite entanglement between magnons and photons. This property can be used for transferring entanglement between different types of quantum systems.

References in corpus (19)

• Microwave photonics with superconducting quantum circuits
• Detection of 15 dB Squeezed States of Light and their Application for the Absolute Calibration of Photoelectric Quantum Efficiency
• Hybrid quantum systems based on magnonics
• Quantum magnonics: when magnon spintronics meets quantum information science
• High Cooperativity Cavity QED with Magnons at Microwave Frequencies
• Deep Strong Coupling Regime of the Jaynes-Cummings model
• Roadmap on Spin-Wave Computing
• Cavity Magnonics
• Cavity Quantum Materials
• Strongly-Correlated Electron-Photon Systems
• The dynamical Casimir effect in superconducting microwave circuits
• Ultra-strong photon-to-magnon coupling in multilayered heterostructures involving superconducting coherence via ferromagnetic layers
• Magnetization dynamics in proximity-coupled superconductor/ferromagnet/superconductor multilayers
• Approaching to the deep-strong photon-to-magnon coupling
• Cavity magnon-polaritons in cuprate parent compounds
• Efficient Gating of Magnons by Proximity Superconductors
• Magnon spin current induced by triplet Cooper pair supercurrents
• Control of the Bose-Einstein Condensation of Magnons by the Spin-Hall Effect
• Listening to the quantum vacuum: a perspective on the dynamical Casimir effect

Cited by in corpus (10)

• Correlation-enhanced interaction of a Bose-Einstein condensate with parametric magnon pairs and virtual magnons
• Electromagnetic Proximity Effect: Superconducting Magnonics and Beyond
• Second-order correlation and squeezing of photons in cavities with ultrastrong magnon-photon interactions
• Buzdin, Shapiro and Chimera Steps in ${\phi }_0$ Josephson Junctions
• Antiferromagnetic resonances in superconductor-ferromagnet multilayers
• Ultra-strong coupling of two ferromagnets via Meissner currents
• Superluminal Propagation of Composite Collective Modes in Superconductor-Ferromagnet Heterostructures
• Circuit-based cavity magnonics in the ultrastrong and deep-strong coupling regimes
• Ultrastrong magnon-photon coupling in superconductor/antiferromagnet/superconductor heterostructures at terahertz frequencies
• Effects of magnonic Kerr nonlinearity on magnon-polaritons with a soft-mode