visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2016-09-02 14:30 
일시 Sep. 02(Fri) 2:30 PM 
장소 E6-2(1st fl.), #1323 
연사 Dr. Yong-Hyun Kim,Graduate School of Nanoscience and Technology, KAIST 

Nanoscale Thermal Physics: Seebeck Effect and Nanoscale Friction

 

Sep. 02(Fri) 2:30 PM, E6-2(1st fl.), #1323
Dr. Yong-Hyun Kim,Graduate School of Nanoscience and Technology, KAIST

 

Abstract:
Heat, a measure of entropy, is largely perceived to be diffusive and transported incoherently by charge carriers (electrons and holes) and lattice vibrations (phonons) in a material. Because heat can be carried by many different (quasi-)particles, it is generally hard to spatially localize the transport of the thermal energy. Heat transport is thus considered to be a challenging means of the local probing of a material and of its electronic states. Recently, we have shown that coherent electron and heat transport through a point-like contact in the atomic force microscope set-up at the ultra-high vacuum condition produces an atomic Seebeck effect, which represents the novel imaging principle of surface wave functions with atomic resolution. The heat-based scanning Seebeck microscopy clearly contrasts to the vacuum tunneling-based scanning tunneling microscopy, a hitherto golden standard of imaging surface wave functions. We have found that the coherent transmission probabilities of electron and phonon across the tip-sample junction are equally important for the imaging capability of the scanning Seebeck microscope. Very recently, we have reported that abnormally enhanced nanoscale friction on ice-trapped graphene surface could be understood in terms of flexural phonon couplings between graphene and substrate (e.g. mica). Also, we have found that energetic tunneling electrons in scanning tunneling microscopy can cause chemical reactions at the single molecule level by locally exciting phonon modes of molecules (or nanoscale heating) under the tip through the inelastic electron-phonon scattering. In this talk, I will discuss how we theoretically explore nanoscale thermal physics including thermoelectric imaging, nanoscale friction, and single molecule chemical reaction, specifically in the setup of scanning probe microscopy.


Contact: Sung Jae Cho, Physics Dept., (sungjae.cho@kaist.ac.kr)

번호 날짜 장소 제목
271 2019-09-27 14:30  E6-2. 1st fl. #1323  Spin-charge conversion in topological insulators for spintronic applications file
270 2019-09-27 16:00  E6-2. 1st fl. #1323  0D/1D/2D/3D III-V materials grown by MBE for Optelectronics file
269 2019-10-15 16:00  #1323, E6-2  Moiré superlattices and graphene quasicrystal file
268 2019-10-16 16:00  #1323 (E6-2, 1st fl.)  Emergent black holes and monopoles from quantum fields file
267 2019-10-17 16:00  #1323, E6-2  Top down manipulation of Waves : From Metamaterials, Correlated Disorder, Quantum Analogy, to Digital Processing file
266 2019-10-25 15:00  #1323, E6-2  Physics Seminar file
265 2019-10-29 10:00  #1323 (E6-2, 1st fl.)  Unconventional Spin Transport in Quantum Materials file
264 2019-10-29 14:30  #1323, E6-2  Quantum sensing file
263 2019-10-29 16:00  #1323 (E6-2, 1st fl.)  Particles and Gravity via String Geometry file
262 2019-10-31 10:00  #1323 (E6-2, 1st fl.)  Kondo meets Hubbard: Impurity physics for correlated lattices file
261 2019-11-01 14:30  E6-2. 1st fl. #1323  Squeezing the best out of 2D materials file
260 2019-11-01 16:00  E6-2. 1st fl. #1323  Electron transport through weak-bonded contact metal with low dimensional nano-material file
259 2019-11-05 16:00  #1323, E6-2  Study on nanomaterials by the development of ultrahigh resolution laser-photoelectron microscopy (PEEM) file
258 2019-11-07 16:00  #1323, E6-2  Integrated quantum photonics with solid-state quantum emitters file
257 2019-11-14 16:00  #1323, E6-2  Semi-classical model of polariton propagation file
256 2019-11-20 16:00  #5302, E6-2  Correlation between superconducting transition temperature and critical current density in irradiated iron-based superconductors file
255 2019-11-28 16:00  #1323, E6-2  Generation of coherent EUV emissions using ultrashort laser pulses file
254 2019-12-03 16:00  #1323, E6-2  Toward Quantum Materials with Correlated Oxides file
253 2019-12-05 16:00  #1323, E6-2  Subwavelenth Photonic Devices: From Single Photon Sources to Solar Cell file
252 2019-12-13 13:00  #2501, E6-2  Computational Material Designs: Current Status and Future Directions file