Polarity-dependent twist-controlled resonant tunneling device based on few-layer WSe_{2}

• Published in: Physical review research 2023-12, Vol.5 (4), p.043292
• Main Authors: Kei Kinoshita, Rai Moriya, Shota Okazaki, Yijin Zhang, Satoru Masubuchi, Kenji Watanabe, Takashi Taniguchi, Takao Sasagawa, Tomoki Machida
• Format: Article
• Language: English
• ISSN: 2643-1564
• DOI: 10.1103/PhysRevResearch.5.043292

Few-layer (FL) transition metal dichalcogenides have been found to exhibit discrete subbands, called van der Waals quantum well (vdWQW) states, resulting from out-of-plane quantum confinement. In this study, we reveal the twisted-resonant tunneling characteristics of a vdWQW device using a three-layer (3L) WSe_{2}/h-BN/3L-WSe_{2} junction with different twist angles θ_{tunnel} between the two 3L WSe_{2} flakes. Using an ambipolar graphene contact to WSe_{2}, two primary vdWQW states of 3L WSe_{2} located in the conduction band (CB) and valence band (VB) were investigated. We found that while the current peak positions due to the electron resonant tunneling between the CB-QW states significantly change with θ_{tunnel} having a periodicity of 60^{∘}, the hole resonant tunneling between the VB-QW states exhibits no θ_{tunnel} dependence; these are due to different angular dispersions of two vdWQWs. The results highlight the different twistronic properties of CB and VB vdWQWs in FL WSe_{2}.