Qi Jia receives best poster award at MMM 2025
Doctoral candidate Qi Jia was the recipient of the MMM 2025 Best Poster Award for his poster titled, “DR-02: NIST SP 800-90B Compliant Perpendicular Magnetic Tunnel Junction Based True Random Number Generator.” The 70th Annual Conference on Magnetism and Magnetic Materials recently concluded in Florida.
Jia has been working on his doctoral research under the guidance of Professor Jian-Ping Wang (Distinguished McKnight University Professor and Robert F. Hartmann Chair in ECE). His conference poster shared the work conducted by Wang’s team in collaboration with Deep Science Ventures on demonstrating magnetic tunnel junctions (MTJs) as true random number generators (TRNGs). MTJs have long been considered a promising TRNG solution, but most prior studies evaluated randomness using the NIST SP 800-20 standard, which no longer meets modern security requirements. In their research, the team generated bitstreams from pulse-switched perpendicular MTJs (pMTJs) and evaluated their entropy using the updated NIST SP 800-90B framework. The output achieves near-ideal entropy after only a single exclusive or operation, establishing MTJs as a highly competitive and practically significant TRNG element.
Jia was also recognized at the conference for his oral presentation titled, “CD-10: Energy-Efficient Control of Probabilistic Switching in sMTJs via Voltage-Controlled Exchange Coupling: Experiment and Simulation.” The oral talk presented the team’s progress on voltage-controlled switching in MTJs. As a fundamental memory element, an MTJ requires a local mechanism to toggle between the high- and low-resistance states. Conventional approaches such as spin-transfer torque (STT) and spin-orbit torque (SOT) rely on charge currents, where most of the energy is dissipated as Joule heating. Voltage control avoids this dissipation, however most prior voltage-based approaches struggle to achieve reliable bipolar switching and therefore cannot yet replace STT or SOT.
The team investigated the voltage-controlled exchange coupling (VCEC) effect in superparamagnetic MTJs and provided definitive experimental evidence for its existence. They identified its electronic origin and demonstrated its ultrafast response, underscoring its potential for high-speed, energy-efficient switching. As a proof of concept, the team showed that a stochastic MTJ (sMTJ) can be reliably switched with an ultralow power consumption of only 40 nanowatts, which is nearly two orders of magnitude lower than that of conventional STT-based sMTJs.