Fluctuating Materials for Probabilistic Computing
Interdisciplinary Areas: | Micro-, Nano-, and Quantum Engineering |
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Project Description
This project is intended to be part of a long-term research area to establish material bases for a probabilistic computer capable of efficiently solving complex problems that can only be solved by digital computers with orders of magnitude greater system complexity and energy requirements. We propose to study magnetic and ferroelectric materials at their metastable states, which have been previously neglected by the scientific community.
The Gilbreth fellow interested in the proposed project will be mentored by PI Z. Chen to design and synthesize noisy materials through film stack engineering, self-assembly or lithographic patterning to exhibit spontaneous fluctuations at GHz rate between two distinct states with a tunable probability, and co-mentored by PI X. Xu to develop an optical characterization tool with high temporal and high spatial resolution to resolve the ultrafast fluctuations. Optical measurements with tens of nm spatial resolution will require focusing light to sub-diffraction-limited size. The general idea is to adopt an optical antenna to focus light into a spot as small as tens of nm in a near-field scanning optical microscopy (NSOM) – like system, and couple that with an ultrafast pump-and-probe Magneto-Optic Kerr Effect (MOKE) system. The expected outcome of the postdoc appointment will be building such a system, and developing a full understanding of these fluctuating materials.
Start Date
May 1, 2020
Postdoc Qualifications
PhD in Electrical Engineering, Material Science, Mechanical Engineering, Physics, or relevant background for magnetic and ferroelectric material synthesis and prototype device fabrication, and optical measurements.
Co-Advisors
Zhihong Chen, zhchen@purdue.edu, School of Electrical and Computer Engineering, https://web.ics.purdue.edu/~chen658/
Xianfan Xu, xxu@ecn.purdue.edu, Mechanical Engineering, https://engineering.purdue.edu/NanoLab/
References
P. Debashis, R. Faria, K. Y. Camsari and Z. Chen, “Design of Stochastic Nanomagnets for Probabilistic Spin Logic,” IEEE Magn. Lett., vol. 9, p. 4305205, 2018
P. Debashis, R. Faria, K. Y. Camsari, S. Datta and Z. Chen, “Correlated Fluctuations in Spin Orbit Torque Coupled Perpendicular Nanomagnets,” Phys. Rev. B, vol. 101, p. 094405, 2020
E. X. Jin and X. Xu, “Enhanced Optical Near Field From a Bowtie Aperture,” Appl. Phys. Lett., vol. 88, no. 15, p. 153110, 2006.
V. Iyer, Y.P. Chen, and X. Xu, "Ultrafast Surface State Spin-Carrier Dynamics in the Topological Insulator Bi2Te2Se", Phys. Rev. Lett. vol 121, 026807, 2018.
P.K. Venuthurumilli, X. Wen, V. Iyer, Y.P. Chen, Y.P., and X. Xu, "Near-Field Imaging of Surface Plasmons from the Bulk and Surface State of Topological Insulator Bi2Te2Se", ACS Photonics, 2019, DOI: https://doi.org/10.1021/acsphotonics.9b00814.