Science Daily August 10, 2023
Random noise in magnetic materials is of potential use in systems such as spiking neuron devices, random number generators and probability bits. An international team of researchers (South Korea, China, USA – Harvard University, Montana State University) has shown electrically tunable magnetic fluctuations and random telegraph noise in multilayered vanadium-doped tungsten diselenide (WSe2) using vertical tunnelling heterostructure devices composed of graphene/vanadium-doped WSe2/graphene and magnetoresistance measurements. They identified bistable magnetic states through discrete Gaussian peaks in the random telegraph noise histogram and the 1/f2 features of the noise power spectrum. Three categories of fluctuation were detected: small resistance fluctuations at high temperatures due to intralayer coupling between the magnetic domains; large resistance changes over a wide range of temperatures; and persistent large resistance changes at low temperatures due to magnetic interlayer coupling. They also show that the bistable state and cut-off frequency of the random telegraph noise could be modulated with an electric bias… read more. TECHNICAL ARTICLEÂ
Time evolution of RTN signals with the corresponding RTN histograms of 1/f 2 feature in the noise power spectra at negative (a) and positive voltage… Credit: Institute for Basic Science