Kyung-Su Kim
Ph.D. Student in Physics, admitted Autumn 2019
All Publications
-
Exact hole-induced resonating-valence-bond ground state in certain U = infinity Hubbard models
PHYSICAL REVIEW B
2023; 107 (14)
View details for DOI 10.1103/PhysRevB.107.L140401
View details for Web of Science ID 000996388400001
-
Interstitial-Induced Ferromagnetism in a Two-Dimensional Wigner Crystal.
Physical review letters
2022; 129 (22): 227202
Abstract
The two-dimensional Wigner crystal (WC) occurs in the strongly interacting regime (r_{s}≫1) of the two-dimensional electron gas (2DEG). The magnetism of a pure WC is determined by tunneling processes that induce multispin ring-exchange interactions, resulting in fully polarized ferromagnetism for large enough r_{s}. Recently, Hossain et al. [Proc. Natl. Acad. Sci. U.S.A. 117, 32244 (2020)PNASA60027-842410.1073/pnas.2018248117] reported the occurrence of a fully polarized ferromagnetic insulator at r_{s}≳35 in an AlAs quantum well, but at temperatures orders of magnitude larger than the predicted exchange energies for the pure WC. Here, we analyze the large r_{s} dynamics of an interstitial defect in the WC, and show that it produces local ferromagnetism with much higher energy scales. Three hopping processes are dominant, which favor a large, fully polarized ferromagnetic polaron. Based on the above results, we speculate concerning the phenomenology of the magnetism near the metal-insulator transition of the 2DEG.
View details for DOI 10.1103/PhysRevLett.129.227202
View details for PubMedID 36493455
-
The quantum Hall effect in the absence of disorder
NPJ QUANTUM MATERIALS
2021; 6 (1)
View details for DOI 10.1038/s41535-021-00321-w
View details for Web of Science ID 000625115000001
-
Discovery of an insulating ferromagnetic phase of electrons in two dimensions.
Proceedings of the National Academy of Sciences of the United States of America
2021; 118 (2)
View details for DOI 10.1073/pnas.2023964118
View details for PubMedID 33408156
-
Magnon topology and thermal Hall effect in trimerized triangular lattice antiferromagnet
PHYSICAL REVIEW B
2019; 100 (6)
View details for DOI 10.1103/PhysRevB.100.064412
View details for Web of Science ID 000481609500005