Terahertz multi-level nonvolatile optically rewritable encryption memory based on chalcogenide phase-change materials

Shoujun Zhang; Xieyu Chen; Kuan Liu; Haiyang Li; Yuanhao Lang; Jie Han; Qingwei Wang; Yongchang Lu; Jianming Dai; Tun Cao; Zhen Tian

doi:10.1016/j.isci.2022.104866

Terahertz multi-level nonvolatile optically rewritable encryption memory based on chalcogenide phase-change materials

iScience. 2022 Aug 2;25(8):104866. doi: 10.1016/j.isci.2022.104866. eCollection 2022 Aug 19.

Authors

Shoujun Zhang¹, Xieyu Chen¹, Kuan Liu², Haiyang Li², Yuanhao Lang¹, Jie Han¹, Qingwei Wang¹, Yongchang Lu¹, Jianming Dai¹, Tun Cao², Zhen Tian^{1

3}

Affiliations

¹ Center for Terahertz Waves and College of Precision Instrument and Optoelectronics Engineering, Key Laboratory of Optoelectronic Information Technology (Ministry of Education of China), Tianjin University, Tianjin 300072, China.
² School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian 116024, China.
³ Georgia Tech Shenzhen Institute (GTSI), Tianjin University, Shen Zhen, 518067, China.

Abstract

Fast and efficient information processing and encryption, including writing, reading, and encryption memory, is essential for upcoming terahertz (THz) communications and information encryption. Here, we demonstrate a THz multi-level, nonvolatile, optically rewritable memory and encryption memory based on chalcogenide phase-change materials, Ge₂Sb₂Te₅ (GST). By tuning the laser fluence irradiated on GST, we experimentally achieve multiple intermediate states and large-area amorphization with a diameter of centimeter-level in the THz regime. Our memory unit features a high operating speed of up to 4 ns, excellent reproducibility, and long-term stability. Utilizing this approach, hexadecimal coding information memories are implemented, and multiple writing-erasing tests are successfully carried out in the same active area. Finally, terahertz photoprint memory is demonstrated, verifying the feasibility of lithography-free devices. The demonstration suggests a practical way to protect and store information and paves a new avenue toward nonvolatile active THz devices.

Keywords: Applied sciences; Devices; Photonics.