Multi-Space Density Functional Theory (MS-DFT)

After a decade-plus effort, we established the multi-space excitation viewpoint for quantum transport, and based on the picture developed the multi-space constrained-search density functional theory (MS-DFT) for non-equilibrium open quantum systems. The multi-space excitation picture and the corresponding MS-DFT represent the alternatives to the standard Landauer viewpoint and the DFT-based non-equilibrium Green's function (NEGF) method, respectively. 

Selected Publications

● ​​​​​​"Multi-space excitation as an alternative to the Landauer picture for nonequilibrium quantum transport​"

Juho Lee, Han Seul Kim, and Yong-Hoon Kim

Advanced Science, Vol. 7, No. 16, Art. 2001038 (2020).

Disruptive 1st-Principles TCAD

Based on MS-DFT and related first-principles methods, we are actively developing science and technology that will enable hitherto unachievable atomistic ​​technology computer-aided design (TCAD) of next-generation semiconductor devices​. We recently demonstrated for the first time ab initio device simulations of graphene-based van der Waals 2D heterojunction transistors. A key focus of our present effort is extending the length and time scales of first-principles electronic structure and ​TCAD calculations by incorporating high-performance and artificial intelligence computing techniques. 

Selected Publications

● ​"Gate-versus defect-induced voltage drop and negative differential resistance in vertical graphene heterostructures"

Tae Hyung Kim, Juho Lee, Ryong-Gyu Lee, and Yong-Hoon Kim

npj Computational Materials, Vol. 8, Art. 50 (2022)