Interlayer magnetophononic coupling in MnBi2Te4

Abstract

The emergence of magnetism in quantum materials creates a platform to realize spin-based applications in spintronics, magnetic memory, and quantum information science. A key to unlocking new functionalities in these materials is the discovery of tunable coupling between spins and other microscopic degrees of freedom. We present evidence for interlayer magnetophononic coupling in the layered magnetic topological insulator MnBi2Te4. Employing magneto-Raman spectroscopy, we observe anomalies in phonon scattering intensities across magnetic field-driven phase transitions, despite the absence of discernible static structural changes. This behavior is a consequence of a magnetophononic wave-mixing process that allows for the excitation of zone-boundary phonons that are otherwise 'forbidden' by momentum conservation. Our microscopic model based on density functional theory calculations reveals that this phenomenon can be attributed to phonons modulating the interlayer exchange coupling. Moreover, signatures of magnetophononic coupling are also observed in the time domain through the ultrafast excitation and detection of coherent phonons across magnetic transitions. In light of the intimate connection between magnetism and topology in MnBi2Te4, the magnetophononic coupling represents an important step towards coherent on-demand manipulation of magnetic topological phases.

References in corpus (3)

• Electrodynamics of Correlated Electron Materials
• Crystal growth and magnetic structure of MnBi2Te4
• Exciton-driven antiferromagnetic metal in a correlated van der Waals insulator

Cited by in corpus (13)

• Terahertz field-induced metastable magnetization near criticality in FePS3
• Two-dimensional THz spectroscopy of nonlinear phononics in the topological insulator ${\mathrm{MnBi}}_2{\mathrm{Te}}_4$
• Observation of the Axion quasiparticle in 2D MnBi${}_2$Te${}_4$
• Quantum Imaging of Magnetic Phase Transitions and Spin Fluctuations in Intrinsic Magnetic Topological Nanoflakes
• Ultrafast coherent interlayer phonon dynamics in atomically thin layers of MnBi2Te4
• Large Itinerant Electron Exchange Coupling in the Magnetic Topological Insulator MnBi2Te4
• Magnetic field-controlled lattice thermal conductivity in MnBi2Te4
• Thermal and thermoelectric properties of an antiferromagnetic topological insulator MnBi${}_2$Te${}_4$
• Non-equilibrium dynamics of spin-lattice coupling
• Ultrafast simultaneous manipulation of multiple ferroic orders through nonlinear phonon excitation
• Phononic dynamical axion in magnetic Dirac insulators
• Tuning magnetic interactions with nonequilibrium optical phonon populations: a theoretical study
• Research on topological materials using ultrafast spectroscopy