Title : Engineering Electronic Transport in Two-Dimensional Materials: From Semiconductors to Superconductors
일시 : 2026년 11월 3일 (화), 17시
장소 : 아산이학관 433호
Speaker : 김재근 (서울시립대학교 자연과학대학 물리학과)
Abstracts:
Controlling the flow of electrons lies at the heart of modern electronics. As electronic devices become increasingly miniaturized, however, their performance is determined not only by the number of charge carriers, but also by how electrons interact with their surrounding environment, interfaces, and the underlying symmetry of the material. Two-dimensional (2D) materials provide a particularly attractive platform for exploring these effects because their electronic properties are highly sensitive to external perturbations and can be tailored through atomically controlled heterostructures.
In this seminar, I will discuss how electronic transport can be controlled in 2D materials. In 2D semiconductors, doping offers a direct way to control charge transport, but simultaneously modifies the environment through which carriers move. Understanding this interplay between carrier density, scattering, and interfaces is therefore essential for improving transport without introducing unwanted limitations. The ability to independently engineer these factors through van der Waals interfaces provides opportunities to control electronic transport beyond conventional doping approaches.
Beyond conventional carrier transport, superconductivity provides a distinct route toward low-dissipation electronics, where electrical transport is governed by macroscopic quantum coherence. In this regime, crystal symmetry, magnetism, and spin-orbit interaction can become active parameters for controlling the flow of supercurrent. One striking example is the superconducting diode effect, in which supercurrent flows differently in opposite directions.
Van der Waals Josephson junctions incorporating noncentrosymmetric Td-WTe₂ demonstrate that broken crystal symmetry can directly generate directional superconducting transport when combined with time-reversal-symmetry breaking. Extending this concept further, engineered superconducting interfaces with different metallic layers demonstrate that magnetic and spin-orbit proximity effects can control not only the magnitude but also the polarity and phase of the superconducting diode response, including its realization without an external magnetic field.
These results illustrate a broader strategy for electronic transport engineering: rather than treating material properties as fixed constraints, interfaces, symmetry, and quantum coherence can be used as design parameters. From controlling carrier transport in two-dimensional semiconductors to manipulating phase-coherent supercurrents in superconducting heterostructures, such approaches offer new opportunities for understanding quantum transport and developing future low-dissipation electronic functionalities.