Phase-Biased Diode Effect in PtTe₂ Josephson Junctions via Symmetry Control

Yi-Chen Tsai^1,4*, Thomas Kuo^1,2, Chia-Nung Kuo³, Chin-Shan Lue³, Kuei-Lin Chiu², Chung-Ting Ke¹

¹Institute of Physics, Academia Sinica, Taipei, Taiwan
²Department of Physics, National Sun Yat-Sen University, Kaohsiung, Taiwan
³Department of Physics, National Cheng Kung University, Tainan, Taiwan
⁴Department of Engineering and System Science, National Tsing Hua University, Hsinchu, Taiwan

* Presenter:Yi-Chen Tsai, email:kaytimothyyc@gmail.com

Control of symmetry breaking is the key to accessing exotic quantum states that enable unique electronic properties for future applications. One architecture to construct the unique quantum state is through a superconducting-normal-superconducting Josephson junction (JJ). Such junction devices may allow us to hybridize exotic quantum states with superconductivity. Typically, JJs maintain symmetry under a small perpendicular magnetic field unless the Andreev channel between superconducting electrodes exhibits a specific order. This study investigates the PtTe₂ Josephson junction with proximitized by superconducting NbTi contacts. Supercurrent through PtTe₂ shows a conventional Fraunhofer pattern under a perpendicular magnetic field. However, both time and inversion symmetry break when applying an in-plane magnetic field along the current direction. Remarkably, inversion symmetry is restored by reversing the in-plane magnetic field and current directions. By rotating the in-plane magnetic field, we observe symmetry with respect to the current direction. This symmetry control allows us to phase-bias the supercurrent under a small perpendicular magnetic field with additional control knobs of the in-plane magnetic field and direction of the supercurrent, leading to the Josephson diode effect (JDE). The phase-biased JDE may provide a new approach for realizing symmetry-controlled quantum electronic devices.

Keywords: TMD materials, Josephson junction, superconductivity, Symmetry breaking, Josephson Diode effect