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
251 2019-08-16 14:00  E6 Room(#1323)  Multiferroic and Magnetoelectric Effects by Tailoring Interfacial Chemistry and Physics in Correlated Oxides file
250 2019-08-14 16:00  Rm. 1323, E6  Quantum Optics, at the heart of quantum metrology and quantum information file
249 2019-08-06 16:00  E6 Room(#1323)  Visualization of in-plane piezoresponse vector fields file
248 2019-08-01 14:00  E6 Room(#1323)  Low-density Superconductivity in SrTiO3 Probed by Planar Tunneling Spectroscopy file
247 2019-07-31 16:00  E6-2, #1323  Features of ballistic superconducting graphene file
246 2019-07-30 16:00  #1323, E6-2  Dirac fermions and flat bands in correlated kagome metals file
245 2019-07-25 16:00  E6-2, #1323  Band topology of twisted bilayer graphene file
244 2019-07-21 12:00  E6-2,# 5318  Challenges and Opportunities in Theoretical Particle Physics 2019 file
243 2019-07-16 16:00  Rm. 1323 (E6-2)  2019 Physics Distinguished Lecture file
242 2019-07-10 16:00  Academic Cltural Complex (E9) 5층 스카이라운지  Public Lectures file
241 2019-07-08 14:00  E6, #1322  Ultrabroadband squeezed pulses and their relation to relativity file
240 2019-07-03 15:00  E6-2, 2501  Many-body quantum electrodynamis (QED) with atoms and photons: A new platform for quantum optics" file
239 2019-06-28 14:00  E6-2, #1322  1st Research-exchange meeting of computational material physics file
238 2019-06-28 13:30  #1323, E6-2  Magnetic domains and domain wall conduction in pyrochlore iridate thin films and heterostructures file
237 2019-06-27 14:00  #2502, E6-2  Gapless Kitaev Spin Liquid to Loop and String Gases file
236 2019-06-24 11:00  E6-2, #1323  Topological photonic anomalies file
235 2019-06-17 10:30  #1323, E6-2  Chiral Spintronics file
234 2019-06-12 15:00  Rm# 1323, E6-2  The relation between free and interacting fermionic SPT phases file
233 2019-06-04 17:00  #1323, E6-2  Stochastic nature of bacterial eradication using antibiotics file
232 2019-05-31 11:00  #1323, E6-2  Cavity QED with Spin Qubits file