korean english


Home > 게시판 > 세미나

아래와 같이 콜로퀴움을 개최하오니 많이 참석해 주시기 바랍니다.

4시 20분부터 제1과학관 31214 e+강의실에서 간단한 다과를 제공합니다.

아 래

Title: 연성물질 기반 위상학적 결함구조의 상전이와 응용

Speaker: 윤   동   기  교수님 (KAIST)

Date & Time: Nov. 8. (Wed.) 2017, 4:30 PM

Place: Natural Science 1,  Room No. 31214

Abstract: Topological defect structure is one of the most interesting topic in physics and material sciences. Especially, the topological defect transition was highlighted by Nobel prize in physics last year. But this topic is hard to understand and realize in the practical condition because the size and time-scale are huge in cosmos or so tiny in skyrmion system. So, we proposed to use liquid crystal (LC) materials to directly show this interesting topic, phase transition of topological defect [1].

In details, LCs are materials in widespread use as the basis of display technologies, have drawn much recent attention for their defects that draw together such concepts as topology, self-assembly, and micro-patterned materials. However, relatively little is known about the fate of the defects during a phase transition from one LC phase to another. Here, we examine defects in the in-situ thermal phase transition from nematic to smectic A in hybrid-aligned LC droplets on water substrates using experimental, theoretical and numerical analyses. The hybrid-aligned nematic droplet spontaneously generates boojum defects. During cooling, toric focal conic domains arise through a sequence of morphological transformations involving nematic stripes and locally aligned focal conic domains. This simple experiment reveals a surprisingly complex pathway by which very different types of defects may be related across the nematic-smectic A phase transition, and presents new possibilities for controlled deformation and patterning of LCs, which are useful in the patterning applications such as hydrophobic surface, illumination, and sensors [2-5].



[1] Min-Jun Gim, et al, “Morphogenesis of liquid crystal topological defects during the nematic-smectic A phase transition” Nature Communications, 8, 15453 (20170

[2] Dae Seok Kim, et al, “Controlling Gaussian and mean curvatures at microscale by sublimation and condensation of smectic liquid crystals” Nature Communications, 7, 10236 (2016)

[3] Dae Seok Kim, et al, “Fabrication of Periodic Nanoparticle Clusters Using Soft Lithographic Template”, J. Mater. Chem. C, 3, 4598 (2015)

[4] Dae Seok Kim, et al, "Fast Fabrication of Sub-200-nm Nanogrooves using Liquid Crystal Material" ACS Applied Materials & Interfaces 8, 11851 (2016)

[5] Dae Seok Kim, et al, “Arrangement and SERS Applications of Nanoparticle Clusters Using Liquid Crystals” ACS Applied Materials & Interfaces, 9, 7787 (2017)


번호 제목 날짜 조회 수
공지 2022학년도 1학기 콜로퀴움 일정 2022.01.10 2231
공지 <12/8(Thu.) 11:00am>노벨상 소개 강연 - 2016년 노벨 물리학상: 위상 응집 물리의 탄생 2016.11.28 813515
148 <11/5> Optical spectroscopic probe on the surface state in three dimensional topological insulators 2012.10.24 62788
147 <10/24> Dung-hai Lee 교수와의 간담회 2012.10.23 62709
146 <11/22> Spin polarization of photoelectrons from a topological insulator 2012.10.22 59332
145 <10/23> Measuring Transfer Reactions with Radioactive Beams 2012.10.15 61180
144 <10/12> Kondo Effect in a Quantum-Dot-Topological-Superconductor Junction: A Numerical Renormalization Group Analysis 2012.10.08 65261
143 <10/5> Gauge fields. Past, present, future. 2012.10.05 59293
142 <10/8 (월)>물리학과 특별세미나 개최 안내 2012.10.05 75601
141 <9/20> Time-reversal anomaly in Josephson effect involving Majorana fermions 2012.09.20 67427
140 <9/14> High temperature superconductivity and fluctuating stripe 2012.09.10 61352
139 <9/7> On Dark Matter and its indirect detection with box-shaped gamma-rays 2012.09.05 61554
138 <9/7(금)> Kondo Effect in Chiral Orbital Bands 2012.08.31 61005
137 <8/7> Scotch tape and spectroscopy: probing and manipulating the surface of a topological insulator 2012.07.27 67530
136 <7월27일>Correlated topological phases in 3D complex oxides via Green's functions 2012.07.27 68956
135 <6/21> Nuclear Astrophysics in Effective Field Theories 2012.06.20 67704
134 <6/19> Kohn's theorem and non-relativistic symmetry 2012.06.15 62470
133 <6/19> 초전도 특별세미나 2012.06.11 71213
132 <6/5> Bilinear Wess-Zumino term for open AdS superstring: covariant description of D-branes 2012.06.04 62829
131 <5/22> Vortex partition function and 3d dualities 2012.05.21 62480
130 <6/5> BK 석학초청 특별강연 - How Well Does High Field Specific Heat Probe the Nodal Nature of the Multi- 2012.05.14 61610
129 <5/16> superconformal index with line operators and domain walls 2012.05.14 60749