[2024]​

 

1. J. Kim*, J. Park*, H. Choi, T. Kim, S. Cha, Y. W. Lee, K. Watanabe, T. Taniguchi, J. Kim, and M-H. Jo, and H. Choi†, "Correlation-driven nonequilibrium exciton site transition in a WSe2/WS2 moiré supercell",
   Nature Communications 15, 3312 (2024) (pdf). *These authors contributed equally to this work.
   
   
   [2023]
   
    

2. D. Wulferding*, J. Kim*, M. K. Kim, Y. Yang, J. H. Lee, D. Song, D. Oh, H.-S Kim, L. E. Chern, Y. B. Kim, M. Noh, H. Choi, S. Choi, N. Perkins, C. Kim†, and S. R. Park†, "Collective magnetic Higgs excitation in a pyrochlore ruthenate",
   npj Quantum Materials 8, 40 (2023) (pdf). *These authors contributed equally to this work.
    

3. J. Lee, J. Kwon, E. Lee, J. Park, S. Cha, K. Watanabe, T. Taniguchi, M.-H. Jo, and H. Choi†, "Spinful hinge states in the higher-order topological insulators WTe2",
   Nature Communications 14, 1801 (2023) (pdf).
   
   
   [2022]
   
    

4. [Invited review] C. In, U. J. Kim†, and H. Choi†, "Two-dimensional Dirac plasmon-polaritons in graphene, 3D topological insulator and hybrid systems",
   Light: Science & Applications 11, 313 (2022) (pdf).
    

5. B. Lee, Y. Ishida, J. Kim, J. Kim, N. H. Jo, S. Y. Kim, I. Kwak, M. Lee, K. Kim, J. H. Kim, M. Jung, S. Shin, T. W. Noh, and H. Choi†, "Ultrafast probes of photovoltage and two-dimensional electron gas in the topological insulator Bi2Te3 by angle-resolved photoemission and terahertz spectroscopy",
   Physical Review B 106, 195430 (2022) (pdf).
    

6. B. Lee*, C. In*, J. Moon, T. Kim, S. Oh, T. W. Noh, and H. Choi†, "Terahertz-driven hot Dirac fermion and plasmon dynamics in the bulk-insulating topological insulator Bi2Se3",
   Physical Review B 105, 045307 (2022) (pdf). *These authors contributed equally to this work.
   
   
    [2021]
   
    

7. G. Jin*, C. Lee*, Odongo F. N. Okello, S. Lee, M. Park, S. Cha, S. Seo, G. Moon, D. Yang, C. Han, H. Ahn, J. Lee, H. Choi, J. Kim, S. Choi, and M. Jo†, "Heteroepitaxial van der Waals semiconductor superlattices",
   Nature Nanotechnology 16, 1092-1098 (2021) (pdf).  *These authors contributed equally to this work.
    

8. S. Seo*, G. Moon*, Odongo F. N. Okello, M. Park, C. Han, S. Cha, H. Choi, H. Yeom, S. Choi, J. Park, and M. Jo†, "Reconfigurable photo-induced doping of two dimensional van der Waals semiconductors using different photon energies",
   Nature Electronics 4, 38-44 (2021) (pdf).  *These authors contributed equally to this work.
    

9. J. Lee*, W. Heo*, M. Cha, K. Watanabe, T. Taniguchi, J. Kim, S. Cha, D. Kim, M. Jo, and H. Choi†, "Ultrafast non-excitonic valley Hall effect in MoS2/WTe2 heterobilayers",
   Nature Communications 12, 1635 (2021) (pdf).  *These authors contributed equally to this work.
    

10. S. Sim*, H. Shin*, D. Lee, J. Lee, M. Cha, K. Lee, and H. Choi†, "Opposite behavior of the ultrafast dynamics of the exciton shift and the linewidth broadening in bilayer ReS2",
    Physical Review B 103, 014309 (2021) (pdf). *These authors contributed equally to this work.
     

11. H. Bae*, S. H. Kim*, S. Lee, M. Noh, O. Karni, A. L. O’Beirne, E. Barré, S. Sim, S. Cha, M. -H. Jo, T. F. Heinz†, and H. Choi†, "Light Absorption and Emission Dominated by Trions in the Type-I van der Waals Heterostructures",
    ACS Photonics 8(7), 1972-1978 (2021) (pdf). *These authors contributed equally to this work.
    
    
     [2020]
    
     

12. S. Paik*, G. Kim*, S. Chang, S. Lee, D. Jin, K. Jeong, I. Lee, J. Lee, H. Moon, J. Lee, K. Chang, S. Choi, J. Moon, S. Jung, S. Kang, W. Lee, H. Choi, H. Choi, H. Kim, J. Lee, J. Cheon, M. Kim, J. Myoung, H. Park, and W. Shim†, "Near-field Sub-diffraction Photolithography with an Elastomeric Photomask",
    Nature Communications 11, 805 (2020) (pdf). *These authors contributed equally to this work.
     

13. Y. Jung*, H. Jung*, H. Choi, and H. Lee†, "Polarization Selective Color Filter Based on Plasmonic Nanograting Embedded Etalon Structures",
    Nano Letters 20, 6344-6350 (2020) (pdf). *These authors contributed equally to this work.
     

14. S. Sim*, D. Lee*, J. Lee, M. Cha, S. Cha, W. Heo, S. Cho, W. Shim, K. Lee, J. Yoo, R. P. Prasankumar, H. Choi†, and M. Jo†, "Role of weak interlayer coupling in ultrafast exciton-exciton annihilation in two-dimensional rhenium dichalcogenides",
    Physical Review B 101, 174309 (2020) (pdf). *These authors contributed equally to this work.
     

15. S. Sim*, S. Lee*, J. Moon, C. In, J. Lee, M. Noh, J. Kim, W. Jang, S. Cha, S. Seo, S. Oh, D. Kim, A. Soon, M. Jo, and H. Choi†, "Picosecond competing dynamics of apparent semiconducting-metallic phase transition in the topological insulator Bi2Se3", 
    ACS Photonics 7, 759-764 (2020) (pdf). *These authors contributed equally to this work.
     

16. Y. Kim*, S. Lee*, J. Song, K. Ko, W. Woo, S. Lee, M. Park, H. Lee, Z. Lee, H. Choi, W. Kim†, J. Park†, and H. Kim†, "2D Transition Metal Dichalcogenide Heterostructures  for p- and n-Type Photovoltaic Self-Powered Gas Sensor",
    Adv. Funct. Mater 30, 2003360 (2020) (pdf). *These authors contributed equally to this work.
    
    
     [2019]
    
     

17. J. -H. Kim*, M. R. Bergren*, J. C. Park*, S. Adhikari, M. Lorke, T. Fraunheim, D. -H. Choe, B. Kim, H. Choi, T. Gregorkiewicz†, and Y. H. Lee†, "Carrier multiplication in van der Waals layered transition metal dichalcogenides",
    Nature Communications 10, 1-9 (2019) (pdf). *These authors contributed equally to this work.
     

18. S. Sim, D. Lee, J. Lee, H. Bae, M. Noh, S. Cha, M. Jo, K. Lee, and H. Choi†, “Light polarization-controlled conversion of ultrafast coherent-incoherent exciton dynamics in few-layer ReS2”,
    Nano Letters 19, 7464−7469 (2019) (pdf).
     

19. J. Kim, C. Jang, X. Wang, J. Paglione, S. Hong, J. Lee, H. Choi, and D. Kim†, "Electrical detection of the surface spin polarization of the candidate topological Kondo insulator SmB6",
    Physical Review B 99, 245148 (2019) (pdf).
     

20. H. G. Kim, I. -K. Oh, S. Lee, S. Jeon, H. Choi, K. Kim, J. H. Yang, J. W. Chung, J. Lee, W. -H. Kim,  and H. -B. -R. Lee†, "Analysis of defect recovery in reduced graphene oxide and its application as a heater for self-healing polymers",
    ACS Appl. Mater. Interfaces 11, 16804-16814  (2019) (pdf).
     

21. [Invited review] C. In and H. Choi†, "Dirac Fermion and Plasmon Dynamics in Graphene and Three-Dimensional Topological Insulators",
    Advanced Optical Materials, 1801334 (2019) (pdf).
    
    
    [2018]
    
     

22. S. Cha*, M. Noh*, J.-H. Kim, J. Son, H. Bae, D. Lee, H. Kim, J. Lee, H. Shin, S. Sim, S. Yang, S. Lee, W. Shim, C.-H. Lee, M.-H. Jo, J. S. Kim, D. Kim, and H. Choi†, "Generation, transport, and detection of valley-locked spin photocurrent in WSe2-graphene-Bi2Se3 heterostructures",
    Nature Nanotechnology 13, 910-914 (2018) (pdf). *These authors contributed equally to this work.
     

23. S.-Y. Seo, J. Park, J. Park, K. Song, S. Cha, S. Sim, S. -Y. Choi, H. W. Yeom, H. Choi, and M. -H. Jo†, “Writing of Monolithic Integrated Circuits on a Two-Dimensional van der Waals Semiconductor with a Scanning Light Probe",
    Nature Electronics 1, 512-517 (2018) (pdf).
     

24. Y. Cho*, J. Park*, M. Kim, Y. Jeong, J. Ahn, T. Kim, H. Choi, Y. Yi, and S. Im†, "Fully Transparent p-MoTe2 2D Transistors Using Ultrathin MoOx/Pt Contact Media for Indium-Tin-Oxide Source/Drain",
    Adv. Funct. Mater  28, 1801204 (2018) (pdf). *These authors contributed equally to this work.
     

25. S. Sim, D. Lee, A. V. Trifonov, T. Kim, S. Cha, J. H. Sung, S. Cho, W. Shim, M. -H. Jo†, and H. Choi†, "Ultrafast quantum beats of anisotropic excitons in atomically thin ReS2",
    Nature Communications 9, 351 (2018) (pdf).
     

26. C. In, S. Sim, B. Kim, H. Bae, H. Jung, W. Jang, M. Son, J. Moon, M. Salehi, S. Y. Seo, A. Soon, M. -H. Ham, H. Lee, S. Oh, D. Kim, M. -H. Jo, and H. Choi†, "Control over electron-phonon interaction by Dirac plasmon engineering in the Bi2Se3 topological insulator",
    Nano Letters 18, 734 (2018) (pdf).
     

27. H. Jung, J. Koo, E. Heo, B. Cho, C. In, H. Jo, J.-H. Cho, H. Choi, M.-S. Kang, and H. Lee†, "Electrically controllable molecularization of terahertz meta-atoms",
    Advanced Materials 30, 1802760 (2018) (pdf).
     

28. W. Yang, S. Lee, H.-C. Kwon, J. Tan, H. Lee, J. Park, Y. Oh, H. Choi, and J. Moon†, "Time-resolved observation of photo-excited charge carrier dynamics in Sb2Se3 photocathodes for photoelectrochemical water splitting: From carrier localization to charge transfer",
    ACS Nano 12(11), 11088-11097 (2018) (pdf).
     

29. H. Jung, H, Jo, W. Lee, B. Kim, H. Choi, M. S. Kang, and H. Lee†, "Electrical Control of Electromagnetically Induced Transparency by Terahertz metamaterial Funneling",
    Advanced Optical Materials 7, 1801205 (2019) (pdf).
     

30. C. In, D. Kim, Y -G Roh, S. W. Kim, H. Lee, Y. Park, S. Kim, U. J. Kim, H. Choi, and S. W. Hwang†, "Photocurrent Engineering of Silicon Nanowire Field-Effect Transistors by Ultrathin Poly(3-hexylthiophene)",
    Advanced Materials Interfaces 5, 1801270 (2018) (pdf).
     

31. J. Lee, S. Sim, S. Park, C. In, S. Cho, S. Lee, S. Cha, S. Lee, H. Kim, J. Kim, W. Shim, J. Kim, D. Kim†, and H. Choi†, "Role of spin Hall effect in the topological side surface conduction",
    ACS Photonics 5(8), 3347-3352 (2018) (pdf).
     

32. [Invited review] C. In and H. Choi†, "Terahertz Investigation of Dirac Materials: Graphene and Topological Insulators",
    Journal of the Korean Physical Society 72, 1484 (2018) (pdf).
     

33. J. Lee*, S. Cho*, S. Park, H. Bae, M. Noh, B. Kim, C. In, S. Yang, S. Lee, S. Y. Seo, J. Kim, C. -H. Lee, W. -Y. Shim, M. -H. Jo, D. Kim, and H. Choi†, "Highly efficient computer algorithm for identifying layer thickness of atomically thin two-dimensional materials",
    Journal of Physics D: Applied Physics 51, 11LT03 (2018) (pdf). *These authors contributed equally to this work.
    
    
    [2017]
    
     

34. J. H. Sung*, S. Cha*, H. Heo, S. Sim, J. Kim, H. Choi†, and M. H. Jo†, "Ultrafast hot-carrier photovoltaics of type-I monolayer heterojunctions in the broad spectral ranges",
    ACS Photonics 4, 429 (2017) (pdf). *These authors contributed equally to this work.
     

35. J. Kim*, S. Park*, H. Jang, Nikesh Koirala, J. B. Lee, U. Kim, H. S. Lee, Y. G. Roh, H. Lee, S. Sim, S. Cha, C. In, J. Park, J. Lee, M. Noh, J. Moon, Maryam Salehi, J. H. Sung, S. S. Chee, M. H. Jo, S. Oh, J. H. Ahn, S. W. Hwang, D. Kim†,  and H. Choi†, "Highly-sensitive, gate-tunable, room-temperature mid-infrared photodetection based on graphene-Bi2Se3 heterostructure",
    ACS Photonics 4, 482 (2017) (pdf). *These authors contributed equally to this work.
     

36. S. S. Chee, C. Oh, M. Son, G. C. Son, H. Jang, T. J. Yoo, S. Lee, W. Lee, J. Y. Hwang, H. Choi, B. H. Lee and M. H. Ham†, "Sulfur vacancy-induced reversible doping of transition metal disulfides via hydrazine treatment",
    Nanoscale 9, 9333 (2017) (pdf).
     

37. W. Jang, J. Lee, C. In, H. Choi and A. Soon†, "Designing two-dimensional Dirac heterointerfaces of few-layer graphene and tetradymite-type Sb2Te3 for thermoelectric applications",
    ACS Appl. Mater. Interfaces 9, 42050 (2017) (pdf).
    
    
    [2016]
    
     

38. S. Sim*, D. Lee*, M. Noh, S. Cha, C. H. Soh, J. H. Sung, M. H. Jo, and H. Choi†, "Selectively tunable optical Stark effect of anisotropic excitons in atomically thin ReS2",
    Nature Communications 7, 13569 (2016) (pdf). *These authors contributed equally to this work.
     

39. S. Cha*, J. H. Sung*, S. Sim, J. Park, H. Heo, M.-H. Jo†, and H. Choi†, “1s intraexcitonic dynamics in monolayer MoS2 probed by ultrafast mid-infrared spectroscopy”,
    Nature Communications 7, 10768 (2016) (pdf). *These authors contributed equally to this work.
     

40. W. Yu†, Q. A. Vu, H. M. Oh, H. G. Nam, H. Zhou, S. Cha, J. Y. Kim, A. Carvalho, M. S. Jeong, H. Choi, A. C. Neto, Y. H. Lee†, and Xi. Duan†, "Unusually efficient photocurrent extraction in monolayer van der Waals heterostructure by tunneling through discretized barriers",
    Nature Communications 7, 13278 (2016) (pdf).
     

41. C. In*, H.-D. Kim*, B. Min†, and H. Choi†, “Photoinduced nonlinear mixing of terahertz dipole resonances in graphene metadevices”,
    Advanced Materials 28, 1495 (2016) (pdf). *These authors contributed equally to this work.
     

42. B. Jeong, I. Hwang, S. H. Cho, E. H. Kim, S. Cha, J. Lee, H. S. Kang, S. M. Cho, H. Choi, and C. Park†, "Solvent-Assisted Gel Printing for Micropatterning Thin Organic–Inorganic Hybrid Perovskite Films",
    ACS Nano 10, 9026 (2016) (pdf).
     

43. S. Sim*, J. Park*, N. Koirala, S. Lee, M. Brahlek, J. Moon, M. Salehi, J. Kim, S. Cha, J. H. Sung, M. H. Jo, S. Oh, and H. Choi†, "Composition control of plasmon-phonon interaction using topological quantum-phase transition in photoexcited (Bi1-xInx)2Se3",
    ACS Photonics 3, 1426 (2016) (pdf). *These authors contributed equally to this work.
     

44. H. Jung, C. In, H. Choi, and H. Lee†, "Electromagnetically induced transparency analogue by self-complementary terahertz meta-atom",
    Advanced Optical Materials 4, 627 (2016) (pdf).
     

45. J. Park, J. G. Song, T. Choi, S. Sim, H. Choi, S. W. Han, H. B. R. Lee, S. H. Kim, H. Kim, "Comparison of hydrogen sulfide gas and sulfur powder for synthesis of molybdenum disulfide nanosheets",
    Current Applied Physics 16, 691 (2016) (pdf).
    
    
    [2015]
    
     

46. S. Sim, H. Jang, N. Koirala, M. Brahlek, J. Moon, J. H. Sung, J. Park, S. Cha, S. Oh, M.-H. Jo, J.-H. Ahn, and H. Choi†, “Ultra-high modulation depth exceeding 2,400 % in the optically-controlled topological surface plasmons”,
    Nature Communications 6, 8814 (2015) (pdf).
     

47. D. B. Velusamy, R. H. Kim, S. Cha, J. Huh, R. Khazaeinezhad, S. H. Kassani, G. Song, S. M. Cho, S. H. Cho, I. Hwang, J. Lee, K. Oh, H. Choi†, and C. Park†, “Flexible transition metal dichalcogenide nanosheets for band selective photo-detection”,
    Nature Communications 6, 8063 (2015) (pdf).
     

48. J.-G. Song, G. Ryu, S.-H. Hwang, S. Sim, C. Lee, T. Choi, H. Jung, Y. Kim, Z. Lee, J.-M. Myoung, C. Dussarrat, C. Lansalot-Matras, J. Park, H. Choi, and H. Kim†, “Controllable synthesis of molybdenum tungsten disulfide alloy for vertically composition-controlled multilayer”,
    Nature Communications 6, 7817 (2015) (pdf).
     

49. H. Heo, J. H. Sung, S. Cha, B.-G. Jang, J.-Y. Kim, G. Jin, D. Lee, J.-H. Ahn, M. J. Lee, J. H. Shim, H. Choi, and M.-H. Jo†, “Interlayer orientation dependent light absorption and emission in monolayer semiconductor stacks”,
    Nature Communications 6, 7372 (2015) (pdf).
     

50. S. Sim, N. Koirala, M. Brahlek, J. H. Sung, J. Park, S. Cha, M.-H. Jo, S. Oh, and H. Choi†, “Tunable Fano quantum-interference dynamics using a topological phase transition in (Bi1-xInx)2Se3”,
    Physical Review B 91, 235438 (2015) (pdf).
     

51. H. Heo, J. H. Sung, G. Jin, D. Lee, J.-H. Ahn, M. J. Lee, S. Cha, H. Choi, and M.-H. Jo†, “Rotation-misfit-free heteroepitaxial stacking and stitching growth of hexagonal transition-metal dichalcogenide monolayers by nucleation kinetics controls”,
    Advanced Materials 27, 3803 (2015) (pdf).
     

52. C. In, J. Seo, H. Kwon, J. Choi, S. Sim, J. Kim, T. Kim, T. Lee, and H. Choi†, “Counterbalanced effect of surface trap and Auger recombination on the transverse terahertz carrier dynamics in silicon nanowires”,
    IEEE Transactions on Terahertz Science and Technology 5, 605 (2015) (pdf).
    
    
    [2014]
    
     

53. H. Jang*, J. Kim*, M.-S. Kim, J. H. Cho, H. Choi†, J.-H. Ahn†, “Observation of the inverse giant piezoresistance effect in silicon nanomembranes probed by ultrafast terahertz spectroscopy”,
    Nano Letters 14, 6942 (2014). (pdf). *These authors contributed equally to this work.
     

54. M. J. Paul, B. Lee, J. L. Wardini, Z. J. Thompson, A. D. Stickel, A. Mousavian, H. Choi, E. D. Minot, and Y.-S. Lee†, “Terahertz induced transparency in single-layer graphene”,
    Applied Physics Letters 105, 221107 (2014). (pdf).
     

55. S. Sim, M. Brahelk, N. Koirala, S. Cha, S. Oh, H. Choi†, “Ultrafast terahertz dynamics of hot Dirac-electron surface scattering in the topological insulator Bi2Se3”,
    Physical Review B 89, 165137 (2014). (pdf).
     

56. H. Jung*, C. In*, H. Choi†, and H. Lee†, “Anisotropy modeling of terahertz metamaterials: polarization dependent resonance manipulation by meta-atom cluster”,
    Scientific Reports 4, 5217 (2014). (pdf).
     

57. J. Kim, J. Oh, C. In, Y.-S. Lee, T. B. Norris, S. C. Jun†, and H. Choi†, “Unconventional terahertz carrier relaxation in graphene oxide: observation of enhanced Auger recombination due to defect saturation”,
    ACS Nano 8, 2486 (2014). (pdf).
    
    
    [2013]
    
     

58. Y. Choi*, S. Sim*, S. J. Lim, Y. H. Lee†, and H. Choi†, “Ultrafast biexciton spectroscopy in semiconductor quantum dots: evidence for early emergence of multiple-exciton generation”,
    Scientific Reports 3, 3206 (2013). (pdf).
     

59. S. Cha, Y. Hong, J. Yang, I. Maeng, S. J. Oh, K. Jeong, J.-S. Suh, S. Haam, Y.-M. Huh†, and H. Choi†, “Ultrafast spin-resolved spectroscopy reveals dominant exciton dynamics in conducting polymer polyaniline”,
    Journal of Physical Chemistry C 117, 20371 (2013). (pdf).
     

60. J. Kim*, S. J. Lim*, S. J. Chae, I. Maeng, Y. Choi, S. Cha, Y. H. Lee†, and H. Choi†, “Ultrafast zero balance of the oscillator-strength sum rule in graphene”,
    Scientific Reports 3, 2663 (2013). (pdf). *These authors contributed equally to this work.
     

61. S. Sim, J. Park, J.-G. Song, C. In, Y.-S. Lee, H. Kim†, H. Choi†, “Exciton dynamics in atomically thin MoS2: interexcitonic interaction and broadening kinetics”,
    Physical Review B 88, 075434 (2013). (pdf).
     

62. M. J. Paul, Y.-C. Chang, Z. J. Thompson, A. Stickel, J. Wardini, H. Choi, E. D. Minot, T.B. Norris, Y.-S. Lee, “High-field terahertz response of graphene”,
    New Journal of Physics 15, 085019 (2013). (pdf).
     

63. J. Choi, H. Jung, H. Lee, and H. Choi, “Electromagnetic dipole coupling mechanism in layered terahertz metamaterials”,
    Optics Express 21, 16975 (2013). (pdf).
     

64. S. H. Lee*, J. Choi*, H.-D. Kim, H. Choi†, and B. Min†, “Ultrafast refractive index control of a terahertz graphene metamaterial”,
    Scientific Reports 3, 2135 (2013). (pdf). *These authors contributed equally to this work.
     

65. J. Kim, I. Maeng, J. Jung, H. Song, J.-H. Son, K. Kim, J. Lee, C.-H. Kim, G. Chae, M. Jun, Y. Hwang, S. J. Lee, J.-M. Myoung, and H. Choi, “Terahertz time-domain measurement of non-Drude conductivity in silver nanowire thin fims for transparent electrode application”,
    Applied Physics Letters 102, 011109 (2013). (pdf).
     

66. I. Maeng, S. C. Lim, S. J. Chae, Y. H. Lee, H. Choi, and J.-H. Son, "Gate-controlled nonlinear conductivity of Dirac fermion in graphene field-effect transistors measured by terahertz time-domain spectroscopy",
    Nano Letters 12, 551 (2012). (pdf).
     

67. J. L. Tomaino, A. D. Jameson, M. J. Paul, J. W. Kevek, A. M. van der Zande, R. A. Barton, H. Choi, P. L. McEuen, E. D. Minot, and Y.-S. Lee, "High-contrast imaging of graphene via time-domain terahertz spectroscopy",
    Journal of Infrared, Millimeter, and Terahertz Waves 33, 839 (2012). (pdf).
    
    
    [2003~2011]
    
     

68. H. Choi, V.-M. Gkortsas, L. Diehl, D. Bour, S. Corzine, J. Zhu, G. Hofler, F. Capasso, F. X. Kartner, and T. B. Norris, “Ultrafast Rabi flopping and coherent pulse propagation in a quantum cascade laser”,

    Nature Photonics 4, 706 (2010). (pdf).
     

69. H. Choi, F. Borondics, D. A. Siegel, S. Zhou, M. C. Martin, A. Lanzara, and R. A. Kaindl, “Broadband electromagnetic response and ultrafast terahertz dynamics of few-layer epitaxial graphene”,

    Applied Physics Letters 94, 172102 (2009). (pdf).
     

70. H. Choi, L. Diehl, Z.-K. Wu, M. Giovanni, J. Faist, F. Capasso, and T. B. Norris, “Time-resolved investigations of electronic transport dynamics in quantum cascade lasers based on diagonal lasing transition”,

    IEEE Journal of Quantum Electronics 45, 307 (2009). (pdf).
     

71. H. Choi, L. Diehl, Z.-K. Wu, M. Giovanni, J. Faist, F. Capasso, and T. B. Norris, “Gain recovery dynamics and photon-driven transport in quantum cascade lasers”,

    Physical Review Letters 100, 167401 (2008). (pdf).
     

72. H. Choi, T. B. Norris, T. Gresch, M. Giovanni, J. Faist, L. Diehl, and F. Capasso, “Femtosecond dynamics of resonant tunneling and superlattice relaxation in quantum cascade lasers”,

    Applied Physics Letters 92, 122114 (2008). (pdf).
     

73. H. Choi, L. Diehl, M. Giovannini, J. Faist, F. Capasso, T. B. Norris, “Femtosecond pump-probe studies of carrier transport and gain dynamics in quantum cascade lasers”,

    Physica Status Solidi (c) 5, 225 (2008). (pdf).
     

74. H. Choi, L. Diehl, F. Capasso, D. Bour, S. Corzine, J. Zhu, G. Hofler, and T. B. Norris, “Time-domain upconversion measurements of group-velocity dispersion in quantum cascade lasers”,

    Optics Express 15, 15898 (2007). (pdf).
     

75. Z.-K. Wu, H. Choi, X. Su, S. Subhananda, P. K. Bhattacharya, and T. B. Norris, “Ultrafast electronic dynamics in unipolar n-doped InGaAs/GaAs self-assembled quantum dots”,

    IEEE Journal of Quantum Electronics 43, 486 (2007). (pdf).
     

76. K.-H. Lee, H. Choi, and W.-Y. Choi, “Analysis of chromatic dispersion-induced second-harmonic distortions including laser dynamics to the second order”,

    IEEE Journal of Quantum Electronics 39, 640 (2003). (pdf).