Field-induced ultrafast modulation of Rashba coupling at room temperature in ferroelectric $\alpha$-GeTe(111)

Abstract

Rashba materials have appeared as an ideal playground for spin-to-charge conversion in prototype spintronics devices. Among them, $\alpha$-GeTe(111) is a non-centrosymmetric ferroelectric (FE) semiconductor for which a strong spin-orbit interaction gives rise to giant Rashba coupling. Its room temperature ferroelectricity was recently demonstrated as a route towards a new type of highly energy-efficient non-volatile memory device based on switchable polarization. Currently based on the application of an electric field, the writing and reading processes could be outperformed by the use of femtosecond (fs) light pulses requiring exploration of the possible control of ferroelectricity on this timescale. Here, we probe the room temperature transient dynamics of the electronic band structure of $\alpha$-GeTe(111) using time and angle-resolved photoemission spectroscopy (tr-ARPES). Our experiments reveal an ultrafast modulation of the Rashba coupling mediated on the fs timescale by a surface photovoltage (SPV), namely an increase corresponding to a 13 % enhancement of the lattice distortion. This opens the route for the control of the FE polarization in $\alpha$-GeTe(111) and FE semiconducting materials in quantum heterostructures.

31 pages, 12 figures

References in corpus (7)

• Highly efficient and tuneable spin-to-charge conversion through Rashba coupling at oxide interfaces
• Metastable ferroelectricity in optically strained $SrTi{O}_3$
• Room-temperature ferroelectric switching of spin-to-charge conversion in GeTe
• Nonequilibrium Charge-Density-Wave Order Beyond the Thermal Limit
• Optical manipulation of Rashba-split 2-Dimensional Electron Gas
• Triple point fermions in ferroelectric GeTe
• Ultrafast Dynamics of the Surface Photovoltage in Potassium Doped Black Phosphorus

Cited by in corpus (6)

• Time- and Angle-Resolved Photoemission Studies of Quantum Materials
• Quantum Confinement and Electronic Structure at the Surface of van der Waals Ferroelectric α-In${}_2$Se${}_3$
• Direct observation of a photoinduced topological phase transition in Bi-doped (Pb,Sn)Se
• Conduction Band Structure and Ultrafast Dynamics of Ferroelectric $\alpha$-GeTe(111)
• Revealing the Microscopic Mechanism of Displacive Excitation of Coherent Phonons in a Bulk Rashba Semiconductor
• High-Throughput Discovery of Two-Dimensional Materials Exhibiting Strong Rashba-Edelstein effect