Cryogenic operation of NanoBridge at 4K for controlling qubit

A nonvolatile resistive switching of NanoBridgeTM (NB) at 4 K has been demonstrated for realizing the quantum-classical interface (QCI), in which the challenging of reset operation at cryogenic temperature is successfully achieved. The set voltage of the NB is increased with decreasing temperature, saturated around 150 K and to be 2.55 V at 4 K. The on-state resistances tuned at 1k-5kΩ show small temperature dependence down to 4 K due to high residual resistivity. The increased reset current of the NB at 4 K is compensated by the process optimization with thermal engineering and the increased Idsat of the select transistor at 4 K, resulting in the stable switching. The low-power QCI featuring NBs is a strong candidate for controlling a large number of qubits at cryogenic temperature.

History Erase Effect of Real Memristors

Different from the static (power-off) nonvolatile property of a memristor, the history erase effect of a memristor is a dynamic characteristic, which means that under the excitation of switching or different signals, the memristor can forget its initial value and reach a unique stable state. The stable state is determined only by the excitation signal and has nothing to do with its initial state. The history erase effect is a desired effect in memristor applications such as memory. It can simplify the complexity of the writing circuit and improve the storage speed. If the memristor’s response depends on the initial state, a state reset operation is required before each writing operation. Therefore, it is of great theoretical and practical significance to judge whether the memristor has a history erase effect. Based on the study of the history erase effect of real memristors, this paper focuses on the history erase effect of a Hewlett-Packard (HP) TiO2 memristor and the Self-Directed Channel (SDC) memristor of Knowm Company. The DC and AC responses of the HP TiO2 memristor are given, and it is pointed out that there is no AC history erase effect. However, considering the parasitic memcapacitance effect, it is found that it has the effect. Based on the theoretical model of the SDC memristor, its history erase properties with and without considering parasitic effects are studied. It should be noted that this study method can be useful for other materials such as Al2O3 and MoS2.