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)
- “Magnetic tunnel junctions,” Jian-Gang (Jimmy) Zhu and Chando Park, Materials Today 9, 36 (2006)
- "Magnetic bistability and controllable reversal of asymmetric ferromagnetic nanorings," Zhu, F.Q., Chern, G.W., Tchernyshyov, O., (...), Zhu, J.G., Chien, C.L. Physics Review Letters 96(2) (2006)
- "The effect of adding a magnetic oxide in the grain boundaries of HAMR media," Bing Zhou, B. S. D. Ch. S. Varaprasad, Zhengkun Dai, David E. Laughlin, and Jian-Gang Zhu, APPLIED PHYSICS LETTERS 113, 082401 (2018).
- "Fabrication of bit patterned media using templated two-phase growth," Vignesh Sundar, XiaoMin Yang, Yang Liu, Zhengkun Dai, Bing Zhou, Jingxi Zhu, Kim Lee, Thomas Chang, David Laughlin, and Jian-Gang (Jimmy) Zhu, APL Materials 5, 026106 (2017)
- "MgO-C interlayer for grain size control in FePt-C media for heat assisted magnetic recording," B. S. D. Ch. S. Varaprasad, Bing Zhou, Tong Mo, David E. Laughlin, and Jian-Gang (Jimmy) Zhu, AIP Advances 7, 056503 (2017)
- "Dynamic Feedback in Ferromagnet–Spin Hall Metal Heterostructures," Ran Cheng, Jian-Gang (Jimmy) Zhu, and Di Xiao, Phys. Rev. Lett. 117, 097202 (2016)
- "Energetic molding of chiral magnetic bubbles," Derek Lau, Vignesh Sundar," Jian-Gang (Jimmy) Zhu, and Vincent Sokalski, Phys. Rev. B 94, 060401 (2016)
- "Distinguishing Random and Spatially Deterministic Noise Components in Heat-Assisted Magnetic Recording," Michael Alex, Hai Li, Gerardo Bertero, and Jian-Gang (Jimmy) Zhu, IEEE Transactions on Magnetics 52, 1 (2016)