Ultrafast optical manipulation of atomic arrangements in chalcogenide alloy memory materials

Abstract

A class of chalcogenide alloy materials that shows significant changes in optical properties upon an amorphous-to-crystalline phase transition has lead to development of large data capacities in modern optical data storage. Among chalcogenide phase-change materials, Ge2Sb2Te5 (GST) is most widely used because of its reliability. We use a pair of femtosecond light pulses to demonstrate the ultrafast optical manipulation of atomic arrangements from tetrahedral (amorphous) to octahedral (crystalline) Ge-coordination in GST superlattices. Depending on the parameters of the second pump-pulse, ultrafast nonthermal phase-change occurred within only few-cycles (~ 1 ps) of the coherent motion corresponding to a GeTe4 local vibration. Using the ultrafast switch in chalcogenide alloy memory could lead to a major paradigm shift in memory devices beyond the current generation of silicon-based flash-memory.

11 pages, 7 figures, accepted for publication in Optics Express

References in corpus (1)

• Evidence for a Structurally-driven Insulator-to-metal Transition in VO2: a View from the Ultrafast Timescale

Cited by in corpus (8)

• Terahertz Devices Using the Optical Activation of GeTe Phase Change Materials: Towards Fully Reconfigurable Functionalities
• Picosecond strain dynamics in Ge${}_2$Sb${}_2$Te${}_5$ monitored by time-resolved x-ray diffraction
• Polarization Dependent Optical Control of Atomic Arrangement in Multilayer Ge-Sb-Te Phase Change Materials
• Thermal conductivity of GeTe/Sb${}_2$Te${}_3$ superlattices measured by coherent phonon spectroscopy
• Coherent phonon study of (GeTe)${}_l$(Sb${}_2$Te${}_3$)${}_m$ interfacial phase change memory materials
• Enhancement of Coherent Phonon Amplitude in Phase-change Materials by Near-infrared Laser Irradiation
• Role of interlayer shear phonons on lattice symmetry switching in the transition metal dichalcogenide WTe${}_2$
• Hybrid Si-GST Polarization-Insensitive Dynamically Tunable Bifocal Metalens Operating at 1.55-$\mu$m Wavelength