Google Scholar

59. Enhanced Thermoelectric Performance of SnSe by Controlled Vacancy Population
Hyejin Ryu, Kyoo Kim, Van Quang Nguyen, Jinwoong Hwang, Ji-Eun Lee, Jonathan Denlinger, Byung Il Min, Sunglae Cho, Sung-Kwan Mo, Hwang Choongyu
(submitted)

58. Imaging spinons in a 2D gapless quantum spin liquid
Wei Ruan, Yi Chen, Shujie Tang, Jinwoong Hwang, Hsin-Zon Tsai, Ryan Lee, Meng Wu, Hyejin Ryu, Salman Kahn, Franklin Liou, Caihong Jia, Andrew Aikawa, Choongyu Hwang, Feng Wang, Yongseong Choi, Steven Louie, Patrick Lee, Zhi-Xun Shen, Sung-Kwan Mo, and Michael F. Crommie*
(submitted)

57. The low-energy electron band structure of a two-dimensional Dirac nodal-line semimetal grown on silicon surface
Hyun-Jeong Joo, Kyoo Kim, and Choongyu Hwang*
J. Kor. Phys. Soc. (accepted)

56. High-quality SnSe₂ single crystal: Electronic and thermoelectric properties
Anh-Tuan Pham, Hoa T. Vu, Cheng Chang, Ly T. Trinh, Ji-Eun Lee, Hyejin Ryu, Choongyu Hwang, Sung-Kwan Mo, Jungdae Kim, Li-dong Zhao, Anh-Tuan Duong, and Sunglae Cho*
ACS Appl. Energy Mater. (ASAP) [PDF preprint]

55. Tunable Kondo resonance at a pristine two-dimensional Dirac semimetal on a Kondo insulator
Jinwoong Hwang, Seungseok Lee, Ji-Eun Lee, Minhee Kang, Hyejin Ryu, Hyunjeong Joo, Jonathan Denlinger, Jae-Hoon Park*, and Choongyu Hwang*
Nano Lett. 20, 7973 (2020) [PDF preprint]

54. A plausible method of preparing the ideal p-n junction interface of a thermoelectric material by surface doping
Ji-Eun Lee, Jinwoong Hwang, Minhee Kang, Hyun-Jeong Joo, Hyejin Ryu, Kyoo Kim, Yongsam Kim, Namdong Kim, Anh Tuan Duong, Sunglae Cho, Sung-Kwan Mo, Choongyu Hwang*, and Imjeong Ho-Soon Yang*
Appl. Surf. Sci. 520, 146314 (2020) [PDF reprint]

53. Controlling the magnetic anisotropy of van der Waals ferromagnet Fe₃GeTe₂
Se Young Park, Dong Seob Kim, Yu Liu, Jinwoong Hwang, Younghak Kim, Wondong Kim, Jae-Young Kim, Cedomir Petrovic, Choongyu Hwang, Sung-Kwan Mo, Byung-Jun Kim, Byoung-Chul Min, Hyun Cheol Koo, Joonyeon Chang, Chaun Jang*, Jun Woo Choi*, and Hyejin Ryu*
Nano Lett. 20, 95 (2020) [PDF preprint]

52. Identifying substitutional oxygen as a prolific point defect in monolayer transition metal dichalcogenides
Sara Barja*, Sivan Refaely-Abramson, Bruno Schuler, Diana Y. Qiu, Artem Pulkin, Sebastian Wickenburg, Hyejin Ryu, Miguel M. Ugeda, Christoph Kastl, Christopher Chen, Choongyu Hwang, Adam Schwartzberg, Shaul Aloni, Sung-Kwan Mo, D. Frank Ogletree, Michael F. Crommie, Oleg V. Yazyev, Steven G. Louie*, Jeffrey B. Neaton*, Alexander Weber-Bargioni*
Nat. Commun. 10, 3382 (2019) [PDF preprint]

51. Ultrafast dynamics of electron-phonon coupling in a metal
Choongyu Hwang*, Wentao Zhang, Koshi Kurashima, Robert Kaindl, Tadashi Koike, and Alessandra Lanzara
EPL 126(5), 57001 (2019) [PDF preprint]

50. Concomitant enhancement of electron-phonon coupling and electron-electron interaction in graphene decorated with ytterbium
Minhee Kang, Jinwoong Hwang, Ji-Eun Lee, Alexei Fedorov, and Choongyu Hwang*
Appl. Surf. Sci. 467-478, 1 (2019) [PDF reprint]

49. Anisotropic Dirac Fermions in BaMnBi₂ and BaZnBi₂
Hyejin Ryu^†*, Se Young Park^†, Lijun Li, Weijun Ren, Jeffrey Neaton, Cedomir Petrovic, Choongyu Hwang, and Sung-Kwan Mo* (†: equal contribution)
Sci. Rep. 8, 15322 (2018) [PDF reprint]

48. Gapped nearly free-standing graphene on an SiC(0001) substrate induced by manganese atoms
Jinwoong Hwang, Ji-Eun Lee, Minhee Kang, Byeong-Gyu Park, Jonathan Denlinger, Sung-Kwan Mo, and Choongyu Hwang*
Appl. Sci. Converg. Technol. 27, 90 (2018) [PDF reprint]

47. Emergence of Kondo resonance in graphene intercalated with cerium
Jinwoong Hwang^†, Kyoo Kim^†, Hyejin Ryu, Jingul Kim, Ji-Eun Lee, Sooran Kim, Minhee Kang, Byeong-Gyu Park, Alessandra Lanzara, Jinwook Chung, Sung-Kwan Mo, Jonathan Denlinger, Byung Il Min, and Choongyu Hwang* (†: equal contribution)
Nano Lett. 18, 3661 (2018) [PDF reprint]

46. Persistent charge-density-wave order in single-layer TaSe₂
Hyejin Ryu*, Yi Chen, Heejung Kim, Hsin-Zon Tsai, Shujie Tang, Juan Jiang, Franklin Liou, Salman Kahn, Caihong Jia, Arash A. Omrani, Ji Hoon Shim, Zahid Hussain, Zhi-Xun Shen, Kyoo Kim, Byung Il Min, Choongyu Hwang, Michael F. Crommie, and Sung-Kwan Mo*
Nano Lett. 18, 689 (2018) [PDF reprint]

45. Electronic structure of monolayer 1T'-MoTe₂ grown by molecular beam epitaxy
Shujie Tang, Chaofan Zhang, Chunjing Jia, Hyejin Ryu, Choongyu Hwang, Zhi Liu, Makoto Hashimoto, Donghui Lu, Thomas P. Devereaux, Zhi-Xun Shen*, and Sung-Kwan Mo*
APL Mater. 6, 026601 (2018) [PDF reprint]

44. Temperature-modulated electronic structure of graphene on SiC: possible roles of electron-electron interaction and strain
Choongyu Hwang*, Jinwoong Hwang, Ji-Eun Lee, Jonathan Denlinger, and Sung-Kwan Mo
Appl. Phys. Lett. 111, 231603 (2017) [PDF reprint]

43. Temperature-dependent electron-electron interaction in graphene on SrTiO₃
Hyejin Ryu^†, Jinwoong Hwang^†, Debin Wang, Ankit S. Disa, Jonathan Denlinger, Yuegang Zhang, Sung-Kwan Mo*, Choongyu Hwang*, and Alessandra Lanzara (†: equal contribution)
Nano Lett. 17, 5914 (2017) [PDF reprint]

42. ARPES study of the epitaxially grown topological crystalline insulator SnTe(111)
Yi Zhang, Zhongkai Liu, Bo Zhou, Yeongkwan Kim, Lexian Yang, Hyejin Ryu, Choongyu Hwang, Yulin Chen, Zahid Hussain, Zhi-Xun Shen, and Sung-Kwan Mo*
J. Electron Spectrosc. Relat. Phenom. 219, 35 (2017) [PDF reprint]

41. Hole doping, hybridization gaps, and electronic correlation in graphene on a platinum substrate
Jinwoong Hwang^†, Hwihyeon Hwang^†, Min-Jeong Kim, Hyejin Ryu, Ji-Eun Lee, Qin Zhou*, Sung-Kwan Mo, Jaekwang Lee, Alessandra Lanzara, and Choongyu Hwang* (†: equal contribution)
Nanoscale 9, 11498 (2017) [PDF reprint]

40. Quantum spin Hall state in monolayer 1T'-WTe₂
Shujie Tang, Chaofan Zhang, Dillon Wong, Zahra Pedramrazi, Hsin-Zon Tsai, Chunjin Jia, Hyejin Ryu, Salman Kahn, Juan Jiang, Hao Yan, Makoto Hashimoto, Donghui Lu, Robert G. Moore, Chancuk Hwang, Choongyu Hwang, Yulin Chen, Zhi Liu, Xiaoming Xie, Thomas P. Devereaux, Michael F. Crommie, Sung-Kwan Mo*, and Zhi-Xun Shen*
Nature Phys. 13, 683 (2017) [PDF reprint]

39. Spin-resolved photoemission study of epitaxially grown MoSe₂ and WSe₂ thin films
S. -K. Mo*, Choongyu Hwang, Y. Zhang, M. Fanciulli, S. Muff, H. Dil, Z. -X. Shen, and Z. Hussain
J. Phys.: Condens. Matter 28, 454001 (2016) [PDF reprint]

38. The hybridizations of cobalt 3d bands with the electron band structure of the graphene/cobalt interface on a tungsten substrate
Jinwoong Hwang, Nak-Kawn Chung, A. D. N'Diaye, Jonathan Denlinger, A. K. Schmid, and Choongyu Hwang*
J. Kor. Phys. Soc. 69, 573-577 (2016) [PDF reprint]

37. Electronic Structure, Surface Doping, and Optical Response in Epitaxial WSe₂ Thin Films
Yi Zhang*, Miguel M. Ugeda, Chenhao Jin, Su-Fei Shi, Aaron J. Bradley, Ana Martin-Recio, Hyejin Ryu, Jonghwan Kim, Shujie Tang, YeongKwan Kim, Bo Zhou, Choongyu Hwang, Yulin Chen, Feng Wang, Michael F. Crommie, Zahid Hussain, Zhi-Xun Shen, and Sung-Kwan Mo*
Nano Lett. 16, 2485 (2016) [PDF reprint]

36. Study on the high spectral intensity at the Dirac energy of single-layer graphene on an SiC substrate
Jinwoong Hwang and Choongyu Hwang*
New J. Phys. 18, 043005 (2016) [PDF reprint]

35. Magnetic effects in sulfur-decorated graphene
Choongyu Hwang*, S. A. Cybart, S. J. Shin, S. Kim, K. Kim, T. G. Rappoport, S. Wu, C. Jozwiak, A. V. Fedorov, S. -K. Mo, D. -H. Lee, B. I. Min, E. E. Haller, R. C. Dynes, A. H. Castro Neto, and A. Lanzara*
Sci. Rep. 6, 21460 (2016) [PDF reprint]

34. Band Modification of Graphene by Using Slow Cs+ Ions
S. J. Sung, S. -H. Lee, P. R. Lee, J. G. Kim, H. M. Park, M. T. Ryu, N. D. Kim, Choongyu Hwang, S. -H. Jhi, and J. W. Chung*
RSC Adv. 6, 9106-9111 (2016) [PDF reprint]

33. Observation of the intrinsic bandgap behaviour in as-grown epitaxial twisted graphene
Jeongho Park*, William C. Mitchel, Said Elhamri, Lawrence Grazulis, John Holescher, Krishnamurthy Mahalingam, Choongyu Hwang, Sung-Kwan Mo, and Jonghoon Lee
Nature Commun. 6, 5677 (2015) [PDF reprint]

32. Tight-binding approach to understand photoelectron intensity from graphene for circularly polarized light
Hwihyeon Hwang and Choongyu Hwang*
J. Electron Spectrosc. Relat. Phenom. 198, 1 (2015) [PDF reprint]

31. Ytterbium-driven strong enhancement of electron-phonon coupling in graphene
Choongyu Hwang*, Duck Young Kim, D. A. Siegel, Kevin T. Chan, J. Noffsinger, A. V. Fedorov, Marvin L. Cohen, Borje Johansson, J. B. Neaton, and A. Lanzara*
Phys. Rev. B 90, 115417 (2014) [PDF reprint]

30. Ultrafast quenching of electron-boson interaction and superconducting gap in a cuprate superconductor
Wentao Zhang, Choongyu Hwang, Chirstopher L. Smallwood, Tristan Miller, Greg Affeldt, Koshi Kurashima, Chris Jozwiak, Hiroshi Eisaki, Tadashi Adachi, Yoji Koike, Dung-Hai Lee, and Alessandra Lanzara*
Nature Commun. 5, 4959 (2014) [PDF reprint]

29. Angle-resolved photoemission spectroscopy study on graphene using circularly polarized light
Choongyu Hwang*
J. Phys.: Condens. Matter 26, 335501 (2014) [PDF reprint]

28. Photoelectron spin-flipping and texture manipulation in a topological insulator
Chris Jozwiak, Cheol-Hwan Park, Kenneth Gotlieb, Choongyu Hwang, Dung-Hai Lee, Steven G. Louie, Jonathan D. Denlinger, Costel R. Rotundu, Robert J. Birgeneau, Zahid Hussain, and Alessandra Lanzara*
Nature Phys. 9, 293-298 (2013) [PDF reprint]

27. Electron-phonon coupling and intrinsic bandgap in highly-screened graphene
David A Siegel, Choongyu Hwang, Alexei V Fedorov, and Alessandra Lanzara*
New J. Phys. 14, 095006 (2012) [PDF reprint]

26. Fermi velocity engineering in graphene by substrate modification
Choongyu Hwang, David A. Siegel, Sung-Kwan Mo, William Regan, Ariel Ismach, Yuegang Zhang, Alex Zettl, and Alessandra Lanzara*
Sci. Rep. 2, 590 (2012) [PDF reprint]

25. Method for synthesis of high quality graphene
Alessandra Lanzara, Andreas K. Schmid, Xiaozhu Yu, Choonkyu Hwang, Annemarie Kohl, Chris M. Jozwiak
U.S. Patent #8142754

24. Direct measurement of quantum phases in graphene via photoemission spectroscopy
Choongyu Hwang, Cheol-Hwan Park, David A. Siegel, Alexei V. Fedorov, Steven G. Louie*, and Alessandra Lanzara*
Phys. Rev. B 84, 125422 (2011). *Editors' Suggestion

23. Many-body interactions in quasi-freestanding graphene
David A. Siegel, Cheol-Hwan Park, Choongyu Hwang, Jack Deslippe, Alexei V. Fedorov, Steven G. Louie, and Alessandra Lanzara*
PNAS 108, 11365-11369 (2011)

22. Observation of intrinsic intraband pi-plasmon excitation of a single-layer graphene
S. Y. Shin, C. G. Hwang, S. J. Sung, N. D. Kim, H. S. Kim, and J. W. Chung*
Phys. Rev. B 83, 161403(R) (2011)

21. New synthesis method for the growth of epitaxial graphene
X.Z. Yu, C.G. Hwang, C.M. Jozwiak, A. Kohl, A.K. Schmid, and A. Lanzara*
J. Electron Spectrosc. Relat. Phenom. 184, 100-106 (2011)

20. Crossover region between nodal and antinodal states at the Fermi level of optimally doped and overdoped Bi₂Sr_1.6Nd_0.4Cu₂O_6+δ
D. R. Garcia, J. Graf, C. Jozwiak, C. G. Hwang, H. Eisaki, and A. Lanzara*
Phys. Rev. B 81, 184527 (2010)

19. Quasifreestanding multilayer graphene films on the carbon face of SiC
D. A. Siegel, C. G. Hwang, A. V. Fedorov, and A. Lanzara*
Phys. Rev. B 81, 241417(R) (2010)

18. Resonant photoluminescent charging of epitaxial graphene
S. D. Lounis, D. A. Siegel, R. Broesler, C. G. Hwang, E. E. Haller, and A. Lanzara*
Appl. Phys. Lett. 96, 151913 (2010)

17. Stability of graphene band structures against an external periodic perturbation; Na on Graphene
C. G. Hwang, S. Y. Shin, S. -M. Choi, N. D. Kim, S. H. Uhm, H. S. Kim, C. C. Hwang, D. Y. Noh, S. -H. Jhi, and J. W. Chung*
Phys. Rev. B 79, 115439 (2009) *Selected article in Vir. J. Nano. Sci. & Tech. 19 (2009)

16. Core-level and valence-band study using angle-integrated photoemission on LaFeAsO_0.9F_0.1
D. R. Garcia, C. Jozwiak, C. G. Hwang, A. Fedorov, S. M. Hanrahan, S. D. Wilson, C. R. Rotundu, B. K. Freelon, R. J. Birgeneau, E. Bourret-Courchesne, and A. Lanzara*
Phys. Rev. B 78, 245119 (2008)

15. Observation of Impurity-Driven Metal-Insulator Transitions in Quasi-1D Nanowires on a (Na, Li)-Added In/Si (111)-4x1 Surface
S. S. Lee, S. Y. Shin, C. G. Hwang, and J. W. Chung*
J. Kor. Phys. Soc. 53, 3667 (2008)

14. Vibrational properties of Na nanoclusters self-assembled on Si(111) surface
C. G. Hwang, N. D. Kim, S. Y. Shin, J. W. Chung*, J. H. Nam, M. K. Kim, C. Y. Park, and J. R. Ahn
Surf. Sci. 602, 2300-2304 (2008)

13. Self-trapping nature of Tl nanoclusters on the Si (111)-7x7 surface
C. G. Hwang, N. D. Kim, G. Lee, S. Y. Shin, J. S. Kim, and J. W. Chung*
New J. Phys. 10, 053013 (2008)

12. Observation of a Temperature-Induced Phase Transition on the Si(5 5 12) Surface
S. H. Uhm, C. G. Hwang, S. Y. Shin, H. S. Kim, and J. W. Chung*
J. Kor. Phys. Soc. 53, 1065-1069 (2008)

11. Atomic structure of a thallium nanodot lattice formed on the Si (111)-7x7 surface
N. D. Kim, C. G. Hwang, J. W. Chung*, Y. Kim, T. C. Kim, D. Y. Noh, K. Sumitani, H. Tajiri, and O. Sakata
Surf. Sci. 602, 369-374 (2008)

10. Ab initio study of thallium nanoclusters on Si (111)-7x7
G. Lee, C. G. Hwang, N. D. Kim, J. Chung, J. S. Kim*, and S. Lee
Phys. Rev. B 76, 245409 (2007)

9. Origin of unusual work function change upon forming Tl nanoclusters on Si (111)-7x7 surface
C. G. Hwang, N. D. Kim, G. Lee, S. Y. Shin, S. H. Uhm, H. S. Kim, J. S. Kim, J. W. Chung*
Appl. Phys. A 89, 431-435 (2007)

8. Possible evidence of non-Fermi liquid behaviour from Quasi-one-dimensional indium nanowires
C. G. Hwang, N. D. Kim, S. Y. Shin, and J. W. Chung*
New J. Phys. 9, 249 (2007)

7. Plasmon excitation observed in quasi one-dimensional nanowires
C. G. Hwang, S. Y. Shin, and J. W. Chung*
J. Phys.: Conf. Ser. 61, 454 (2007)

6. Formation of thallium islands on the Si (111)-7x7 surface
N. D. Kim, C. G. Hwang, J. W. Chung*, T. C. Kim, and D. Y. Noh
Phys. Rev. B 72, 035338 (2005)

5. Structural properties of a thallium-induced Si (111)-1x1 surface
N. D. Kim, C. G. Hwang, J. W. Chung*, T. C. Kim, H. J. Kim, and D. Y. Noh
Phys. Rev. B 69, 195311 (2004)

4. Structural and electronic properties of the quasi-one-dimensional metallic chains of the Au-induced facets on the Si(5 5 12) surface
S. S. Lee, N. D. Kim, C. G. Hwang, H. J. Song, and J. W. Chung*
Phys. Rev. B 66, 115317 (2002)

3. Structural and electronic properties of the Si-rich 6H-SiC(0001) surface
J. R. Ahn, S. S. Lee, N. D. Kim, C. G. Hwang, J. H. Min, and J. W. Chung*
Surf. Sci. 516, L529-L534 (2002)

2. Adsorbate-Induced Pinning of a Charge-Density Wave in a Quasi-1D Metallic Chains: Na on the In/Si (111)-(4x1) Surface
S. S. Lee, J. R. Ahn, N. D. Kim, J. H. Min, C. G. Hwang, J. W. Chung*, H. W. Yeom, S. V. Ryjkov, and S. Hasegawa
Phys. Rev. Lett. 88, 196401 (2002)

1. Observation of disorder-induced 2D Mott-Hubbard states of the alkali-earth metal (Mg, Ba)-adsorbed Si(111) surface
J. R. Ahn, S. S. Lee, N. D. Kim, J. H. Min, C. G. Hwang, and J. W. Chung*
Phys. Rev. Lett. 84, 1748-1751 (2000)