Low-frequency noise in hBN/MoS2/hBN transistor at cryogenic temperatures toward low-noise cryo-CMOS device applications

As an application of cryo-CMOS technology for use in future quantum computing, we have explored low-frequency noise reduction in a two-dimensional (2D) system consisting of a molybdenum disulfide (MoS2) channel sandwiched by hexagonal boron nitride (hBN) layers. Due to the passivation effect of hBN layers, low-frequency noise in hBN/MoS2/hBN channel devices exhibited substantial reduction compared to the case of MoS2 channel directly on a silicon dioxide substrate and also silicon devices, suggesting that the clean interface of substrate and gate dielectric layers, as well as the protected surface of the MoS2 channel by hBN passivation from the damage by the fabrication process, contribute to the strong reduction in low-frequency noise. The results indicated that 2D materials are suitable for cryo-CMOS technology in terms of low-frequency noise since they will bring about mitigation of one of the most serious causes of quantum phase decoherence of qubits in future large-scale integrated quantum computers.