@article{Jang2022,

title = {Direct observation of multiband charge density waves in NbTe2},

author = {Won-Jun Jang and Junyoung Sim and Jin Eun Heo and Heeyoon Noh and Ryung Kim and Seo Hyoung Chang and Sangjun Jeon and Hyo Won Kim},

doi = {10.1103/physrevb.106.125110},

issn = {2469-9969},

year  = {2022},

date = {2022-09-09},

urldate = {2022-09-09},

journal = {Phys. Rev. B},

volume = {106},

number = {12},

publisher = {American Physical Society (APS)},

abstract = {The electronic structure of periodic lattice distortion (PLD) in NbTe2 was examined using low-temperature scanning tunneling spectroscopy and microscopy. The striped PLDs with 3×1 and 1×9/2 superstructures were characterized in real and reciprocal space. The simultaneous formation of momentum-specific suppressions in the spectral weight and phase shifts of the wavefront related to the superstructures were observed at multiple energies. These unusual energy dependencies are well agreed with the charge density waves (CDWs) formed in the multiband electronic structure of NbTe2. Fermi-surface nesting and reconstruction of the reciprocal lattice were suggested in developing the multiband CDWs in NbTe2.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Kim2021a,

title = {Spin resonance amplitude and frequency of a single atom on a surface in a vector magnetic field},

author = {Jinkyung Kim and Won Jun Jang and Thi Hong Bui and Deung Jang Choi and Christoph Wolf and Fernando Delgado and Yi Chen and Denis Krylov and Soonhyeong Lee and Sangwon Yoon and Christopher P Lutz and Andreas J Heinrich and Yujeong Bae},

doi = {10.1103/PhysRevB.104.174408},

issn = {24699969},

year  = {2021},

date = {2021-11-01},

urldate = {2021-11-01},

journal = {Physical Review B},

volume = {104},

number = {17},

publisher = {American Physical Society (APS)},

abstract = {We investigated spin-1/2 hydrogenated titanium (Ti) atoms on MgO using scanning tunneling microscopy (STM) combined with electron spin resonance (ESR) in vector magnetic fields. Rotating external magnetic fields, we observed rather drastic changes in both amplitude and frequency of resonance signals for single Ti atoms. While the variation of ESR amplitudes reflects the effects of the spin polarization of a magnetic tip and local magnetic fields created by the interaction between the tip and Ti, the change of resonance frequencies shows the anisotropy of g values for Ti atoms. Using the Ti atoms at the low-symmetry bridge adsorption site of the MgO lattice allowed for identifying the g values in all three spatial directions. Multiplet calculations confirmed the origin of this anisotropy as the spin-orbit coupling induced effects of crystal. Our results show the capability of single atomic spins as a sensor to probe magnetic surroundings and highlight the precision of ESR-STM to identify the single atom's spin states in a solid-state environment.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Choi2017a,

title = {Switching Magnetism and Superconductivity with Spin-Polarized Current in Iron-Based Superconductor},

author = {Seokhwan Choi and Hyoung Joon Choi and Jong Mok Ok and Yeonghoon Lee and Won Jun Jang and Alex Taekyung Lee and Young Kuk and Sungbin Lee and Andreas J Heinrich and Sang Wook Cheong and Yunkyu Bang and Steven Johnston and Jun Sung Kim and Jhinhwan Lee},

doi = {10.1103/PhysRevLett.119.227001},

issn = {10797114},

year  = {2017},

date = {2017-11-01},

urldate = {2017-11-01},

journal = {Physical Review Letters},

volume = {119},

number = {22},

publisher = {American Physical Society (APS)},

abstract = {We explore a new mechanism for switching magnetism and superconductivity in a magnetically frustrated iron-based superconductor using spin-polarized scanning tunneling microscopy (SPSTM). Our SPSTM study on single-crystal Sr2VO3FeAs shows that a spin-polarized tunneling current can switch the Fe-layer magnetism into a nontrivial C4 (2×2) order, which cannot be achieved by thermal excitation with an unpolarized current. Our tunneling spectroscopy study shows that the induced C4 (2×2) order has characteristics of plaquette antiferromagnetic order in the Fe layer and strongly suppresses superconductivity. Also, thermal agitation beyond the bulk Fe spin ordering temperature erases the C4 state. These results suggest a new possibility of switching local superconductivity by changing the symmetry of magnetic order with spin-polarized and unpolarized tunneling currents in iron-based superconductors.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Jang2015,

title = {Observations of New Dirac Points in One-Dimensionally-Rippled Graphene on Hexagonal BN Using Scanning Tunneling Spectroscopy},

author = {Won-Jun Jang and Min Wook Lee and Howon Kim and Sangwoo Park and Seong Jun Jung and Sungjoo Lee and Young Jae Song and Se-Jong Kahng},

doi = {10.1021/acs.jpcc.5b05835},

issn = {1932-7455},

year  = {2015},

date = {2015-08-20},

journal = {J. Phys. Chem. C},

volume = {119},

number = {33},

pages = {19535--19538},

publisher = {American Chemical Society (ACS)},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Jang2014,

title = {Observation of spatially-varying Fermi velocity in strained-graphene directly grown on hexagonal boron nitride},

author = {Won-Jun Jang and Howon Kim and Yong-Ro Shin and Min Wang and Sung Kyu Jang and Minwoo Kim and Sungjoo Lee and Sang-Woo Kim and Young Jae Song and Se-Jong Kahng},

doi = {10.1016/j.carbon.2014.03.015},

issn = {0008-6223},

year  = {2014},

date = {2014-03-15},

journal = {Carbon},

volume = {74},

pages = {139--145},

publisher = {Elsevier BV},

keywords = {},

pubstate = {published},

tppubtype = {article}

}