Antimony as a Programmable Element in Integrated Nanophotonics

The use of nonlinear elements with memory as photoniccomputing components has seen a huge surge in interest in recent yearswith the rise of artificial intelligence and machine learning. A keycomponent is the nonlinear element itself. A class of materials known asphase change materials has been extensively used to demonstrate theviability of such computing. However, such materials continue to haverelatively slow switching speeds, and issues with cyclability related tophase segregation of phase change alloys. Here, using antimony (Sb)thinfilms with thicknesses less than 5 nm we demonstrate reversible,ultrafast switching on an integrated photonic platform with retentiontime of tens of seconds. We use subpicosecond pulses, the shortest usedto switch such elements, to program seven distinct memory levels. This portends their use in ultrafast nanophotonic applicationsranging from nanophotonic beam steerers to nanoscale integrated elements for photonic computing

Automated summary

The use of nonlinear elements with memory in photonic computing has gained significant interest due to the rise of artificial intelligence and machine learning. Phase change materials are commonly used for demonstrating the feasibility of such computing, but they suffer from slow switching speeds and phase segregation issues. In this study, we demonstrate reversible, ultrafast switching using sub-5 nm antimony thin films on an integrated photonic platform, with a retention time of tens of seconds. By programming seven distinct memory levels using subpicosecond pulses, this research suggests the potential use of these elements in ultrafast nanophotonic applications.