A low standby-power fast carbon nanotube ternary SRAM cell with improved stability *Project supported by the National Natural Science Foundation of China (Nos. 61474068, 61234002, 61404076), the S&T Plan of Zhejiang Provincial Science and Technology Department (No. 2016C31078), and the K.C. Wong Magna Fund in Ningbo University, China. (August 2018)