Quantum memristor based on coupled quantum dots

The memristor is a proposed fourth fundamental circuit element whose electrical resistance is determined by the current that has previously passed through it. Realization of devices that exhibit these characteristics could allow for the implementation of low power non-volatile memory and neuromorphic computing. Here, we propose and demonstrate a novel memristive system using two capacitively coupled Si metal-oxide-semiconductor quantum dots in a parallel configuration. The current flowing through one dot is controlled by the charge state of the other dot via the capacitive coupling. By connecting the applied bias to both dots (making this a two-terminal device), the charge state of the control dot depends on the bias. This allows a hysteretic evolution to take place with an applied AC bias, under certain conditions. The properties of the current hysteresis are modulated through the application of DC voltages to the electrostatic gates that define the dots, providing a means to tune the behavior in-situ. Unlike classical memristive systems, this quantum memristive system shows stochastic behavior due to quantum jumps of the charge state of the control dot.