Dr. Zhu’s research has been in the field of magnetic data storage technologies. His research work on the microstructure of thin film recording media has been pivotal for hard disk drives to reach today’s storage capacity. He has pioneered the research on utilizing micromagnetic modeling for MRAM memory design and established some of the most fundamental design principles used today.
Magnetic Recording Technology for Hard Disk Drives and Digital Tape Recording: Magnetic recording technology has been advancing in dramatically rapid pace over the past decade during which we have made some important contributions. At present, our research includes:
- Development of novel recording mechanisms that enables area storage density exceeding 1 Tbits/in^2 for hard disk drive applications;
- Development of novel perpendicular thin film media microstructures that capable of high area density applications;
The research is supported by DSSC and its industrial sponsors.
Innovative Designs of Magnetic Random Access Memory (MRAM): MRAM has the potential to replace SRAM, DRAM, FLASH, and even a small disk drive to be the universal memory for computer data storage, enabling an entire computer system to be made on a single chip. Our research focuses on novel MRAM designs that offer robust and repeatable magnetic switching characteristic, low operation power capability, and sufficient thermal-magnetic stability. Micromagnetic modeling on computers is utilized to aid the design process and the devices are fabricated using the state-of-the-art e-beam and optical lithographic fabrication technology. Our collaborators include the Naval Research Laboratory and Nonvolatile Electronics Corporation. This research is current funded by the Office of Naval Research, Pittsburgh Digital Green House, STMicroelectronics, and DSSC.
Understanding Noise in Nano-Magnetic Systems: Thermally excited magnetization precession and spin current induced chaotic spin waves are two important causes of magnetic noise in advanced nano-scale magnetic sensors. We perform both theoretical analysis and experimental measurements to obtain a good understanding of the noise and the corresponding underlying physics. This research is supported by Seagate Technology and DSSC.
- "Ultrahigh density vertical magnetoresistive random access memory," Jian-Gang (Jimmy) Zhu, Youfeng Zheng, and Gary A. Prinz, J. Appl. Phys 87, 6668 (2000)
- "Microwave assisted magnetic recording," Jian-Gang (Jimmy) Zhu, Xiaochun Zhu, and Yuhui Tang, IEEE Transactions on Magnetics 44, 125 (2008)
- "Micromagnetic studies of thin metallic films," Jian-Gang (Jimmy) Zhu and H. Neal Bertram, J. Appl. Phys 63, 3248 (1988)
- "Magnetoresistive Random Access Memory: The Path to Competitiveness and Scalability." Jimmy Zhu. Proceedings of IEEE 96.11 (2008)
- “Magnetic tunnel junctions,” Jian-Gang (Jimmy) Zhu and Chando Park, Materials Today 9, 36 (2006)
- "Resonant Spin-Transfer Torque Magnetoresistive Memory." Jian-Gang Zhu and Abir Shadman. IEEE Transactions on Magnetics 55.3 (2019)
- "Field-Free Magnetization Switching by Utilizing the Spin Hall Effect and Interlayer Exchange Coupling of Iridium." Yang Liu, Bing Zhou, and Jian-Gang (Jimmy) Zhu. Scientific Reports 9.1 (2019)
- "High-Speed STT MRAM Incorporating Antiferromagnetic Layer." Abir Shadman and Jian-Gang Zhu. Applied Physics Letters 114.2 (2019)
- "Interlayer Couplings Mediated by Antiferromagnetic Magnons." Ran Cheng, Di Xiao, and Jian-Gang Zhu. Phys. Rev. Lett. 121 (2018)
- "Novel Cascadable Magnetic Majority Gates for Implementing Comprehensive Logic Functions." Xin Li, Min Song, Nuo Xu, Shijiang Luo, Qiming Zou, Shuai Zhang, Jeongmin Hong, Xiaofei Yang, Tai Min, Xiufeng Han, Xuecheng Zou, Jian-Gang Zhu, Sayeef Salahuddin, and Long You. IEEE Transactions on Electron Devices 99 (2018)