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
143 2018-03-16 16:00  E6-2. 1st fl. #1323  Van der Waals Heterostructures from Quantum Transport to Ultrafast Optoelectronics file
142 2019-03-29 16:00  E6-2. 1st fl. #1323  Coherent Quantum Control and Magnetism on atoms – Trapped ion and ESR STM file
141 2019-04-19 16:00  E6-2. 1st fl. #1323  Graphene and hBN heterostructures file
140 2019-04-19 14:30  E6-2. 1st fl. #1323  A family of finite-temperature electronic phase transitions in graphene multilayers file
139 2018-12-26 16:00  E6-2. 1st fl. #1323  Brane-like defect in 3D toric code file
138 2017-06-02 14:30  E6-2. 1st fl. #1323  Quasiparticle Interference and Fourier transform scanning tunneling spectroscopy in WTe2 (Weyl semimetal) file
137 2022-11-18 14:30  E6-2. 1st fl. #1323 & Zoom  Kondo cloud condensation in a highly-doped semiconductor metal file
136 2022-11-18 16:00  E6-2. 1st fl. #1323 & Zoom  Qubits, new experimental tools for physics file
135 2022-09-30 14:30  E6-2. 1st fl. #1323 & Zoom  Putting a spin on the Josephson effect file
134 2022-09-30 16:00  E6-2. 1st fl. #1323 & Zoom  Spin-orbit torque-based spintronic devices file
133 2022-05-25 16:00  E6-2. 1st fl. #1323 / Zoom  Uncovering New Lampposts for Dark Matter: Continuum or Conformal
132 2016-04-01 14:30  E6-2. 1st fl. #1501  Interference of single charged particles without a loop and dynamic nonlocality
131 2016-04-01 16:15  E6-2. 1st fl. #1501  Cotunneling drag effect in Coulomb-coupled quantum dots
130 2016-03-11 16:00  E6-2. 1st fl. #1501  Jan. Switching handedness of of chiral solitons in Z4 topological insulators
129 2016-04-08 13:30  E6-2. 1st fl. #1501  Theoretical Overview of Iron-based superconductors and its future
128 2016-03-11 13:30  E6-2. 1st fl. #1501  Topological phases of matter in nonequilibrium: Topology of the Wannier-Stark ladder
127 2019-01-09 16:00  E6-2. 2nd fl. #2501  Molecular Mott state in the deficient spinel GaV4S8 file
126 2015-10-16 16:00  E6-2. 2nd fl. #2501  Fluctuations of entropy production in partially masked electric circuits
125 2015-09-14 14:00  E6-2. 2nd fl. #2501  Ultrafast X-ray Studies on Dynamics Matter in Extreme Conditions
124 2018-06-18 10:00  E6-2. 2nd fl. #2502  Rydberg electromagnetically induced transparency and microwave-to-optical conversion using Rydberg atoms file