Grant: Idea to Innovation

The enormous energy demands associated with multicore computer architectures and the expected exponential growth over the next 10-15 of cloud storage and computing needs has led to the ""power wall"", causing an intense search for new nonvolatile memory technologies within the semiconductor sector. Nonvolatile memory (NVM) combines high storage density, fast random access, and non-volatility allowing integration across multiple layers of the memory hierarchy but with decreased leakage current and lower power requirements. The most promising emergent nonvolatile memory technologies to date include spin-transfer torque random-access memory (STT-RAM), and phase-change random-access memory (PCRAM). Both exhibit comparable read/write speeds to SRAM and decreased power requirements, but are currently limited predominantly by large cell sizes, which decreases the memory capacity per square area on a chip.We have developed a material that exhibits light-induced changes in magnetization upon irradiation with low-level visible light at room temperature. This allows for the first time fabrication of nonvolatile memory devices in which the storage ""0"" and ""1"" bits can be written with light. The advantage of this technology is that light offers greater temporal and spatial resolution for high-density read-write technologies. The photomagnetic properties of this material have been demonstrated by spectroscopy in the solid state. Here we aim to develop a prototype device in which our photomagnetic material is incorporated into a magnetic tunnel junction as the ""write"" layer. The write process would require application of 550 nm green light in one direction, with 400 nm light or thermal energy as the reverse ""write "" process. The read process would utilize reading of resistivity changes through a magnetic tunnel junction, in an analogous architecture to STT-RAM devices. The results of these experiments will guide further design and experiment as to modifications of the material necessary for CMOS integration, and allow development of a powerful new nonvolatile memory technology for low power computing architectures with low power demands and stability.