Multi-bit cryogenic flash memory on Si/SiGe and Ge/GeSi heterostructures

To realize a full-scale solid-state computer, both quantum processors and classical logic controllers are suggested to be operated at cryogenic temperatures to avoid the issues of signal latency through the room-temperature controllers and the corresponding wiring complexity, and interface of quantum processors and classical controllers. While cryo-CMOS devices have been the main focus recently to address those issues, there were only few works on cryogenic memory devices published [1]. Potential candidates for cryogenic applications are based on Si MOS platforms, which would result in integration challenges with Si/SiGe [2] or Ge/GeSi [3] qubit devices. In this work, we demonstrate multi-bit cryogenic flash operations on both Si/SiGe and Ge/GeSi heterostructures for the first time at 4 K with a high endurance of > 103, long retention time of > 103 s, and a memory window of > 0.2V.