visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
장소 E6 Room(#2501) 
일시 May. 25th (Wed), 14:00 
연사 Dr. Duk-Hyun Choe(Samsung Advanced Institute of Technology) 

Physics Seminar

 

 

 

Atomic-level insights into ferroelectric switching and preferred orientation of ultrathin hafnia

 

Duk-Hyun Choe

Samsung Advanced Institute of Technology

May. 25th (Wed), 14:00, E6 Room(#2501)

 

Over the past decade there has been a resurgence of interest in ferroelectric (FE) devices in the semiconductor device community. This interest was sparked by the discovery of ferroelectricity in a simple binary oxide, hafnia. Unlike conventional FE perovskite, FE hafnia exhibits ultra-scalable ferroelectricity compatible with Si electronics, providing an unprecedented opportunity for the use of FEs in advanced memory and logic devices. Many proof-of-concept devices based on FE hafnia are indeed showing some promise. However, their practical engineering is still largely relying on trial-and-error process that lacks a clear theoretical guidance, and it remains challenging to rationally design the FE devices for targeted applications. Thus, the community is now calling for more fundamental investigations on the physics of ferroelectricity in hafnia.

In this presentation, we briefly review the status of the field and provide our new understanding on FE switching and surface stability of hafnia. We will first introduce an ultralow FE switching mechanism that can enable rapid growth of the FE domains in hafnia [1]. We also establish a new class of topological domain walls in HfO2, which can help understand complex domain structures often present in FE hafnia samples. Next, we present our systematic study of surface-functionalized FE hafnia [2]. We show that their remnant polarization (Pr) and coercive field (Ec) can strongly depend on the surface treatments, providing a possible explanation for the enhancement of Pr in ultrathin hafnia with preferred orientation [3,4]. We believe our study represents an important step towards bridging the gap between practical engineering and the first-principles simulations in the field of FE hafnia.

 

[1] D.-H. Choe et al., Mater. Today 50, 8 (2021).

[2] D.-H. Choe et al., IEDM (2021).

[3] S. S. Cheema et. al., Nature 580, 478 (2020)

[4] H. Lee, D.-H. Choe, S. Jo 36499 (2021).13,  ACS Appl. Mater. Interfaces et. al.,

 

Contact: Prof. Chan-Ho Yang (chyang@kaist.ac.kr) ,

Departmentof Physics / Center for Lattice Defectronics

 

Department of Physics, KAIST

번호 일시 장소 연사 제목
공지 Sep.22 2022  E6-1 #1323    2022 가을학기 응집물리 및 광학 세미나 전체 일정
323 Apr. 01 (Fri.) 4:15 PM  E6-2. 1st fl. #1501  Dr. JONG SOO LIM, KIAS  Cotunneling drag effect in Coulomb-coupled quantum dots
322 Apr. 08 (Fri.), 13:30 PM  E6-2. 1st fl. #1501  Dr. Yunkyu Bang, Chonnam National Univ.  Theoretical Overview of Iron-based superconductors and its future
321 Apr. 08 (Fri.), 4:00 PM  E6-2. 5st fl. #1501  Dr. Changyoung Kim, SEOUL NATIONAL UNIV.  Spectroscopic studies of iron-based superconductors : what have we learned?
320 Apr. 09 (Mon.), 11:00 AM  E6-2. 1st fl. #1323  Dr. Seung-Sup B. Lee  Doublon-holon origin of the subpeaks at the Hubbard band edges file
319 Apr. 1(Fri.), 04:00 PM  Zoom webinar  Dr. Kayoung Lee (KAIST)  High-field Electron Transport and Interaction Induced Phenomena in 2D Materials file
318 Apr. 12 (Tue.), 4 PM  E6-2. 1st fl. #1323  Dr. Jeehoon Kim, POSTECH  Confinement of Superconducting Vortices in Magnetic Force Microscopy
317 Apr. 13(Wed.) 10:30Am  E6 #1323/zoom  Mingu Kang (Max Planck POSTECH Korea Research Initiative)  Harnessing topology and correlations from singularities in 3d-kagome metals
316 Apr. 19 (Fri.), 02:30 PM  E6-2. 1st fl. #1323  Dr. YoungWoo Nam  A family of finite-temperature electronic phase transitions in graphene multilayers file
315 Apr. 19 (Fri.), 04:00 PM  E6-2. 1st fl. #1323  Dr. Seok Kyun Son  Graphene and hBN heterostructures file
314 Apr. 19(Mon) 19:00  Zoom webinar  Chia-Ling Chien (Johns Hopkins, USA)  Evidence of Electrical Switching in Antiferromagnets and Coherent Spin Pumping file
313 Apr. 19(Tue.), 2PM  #1323(E6-2. 1st fl.)  Prof. Mark Koepke, Department of Physics and Astronomy, West Virginia University, USA  Nonlocal collisional electron transport in partially ionized plasma generation, structure, and stability
312 Apr. 2 (Fri.), 02:30 PM  Online(Zoom)  Dr. Tae Hyun Kim (SNU)  Quantum computing and entanglement generation using trapped ions and photons
311 Apr. 2 (Fri.), 04:00 PM  Online(Zoom)  Dr. Heejun Yang (KAIST)  Van der Waals heterostructures for orbital gating-based phototransistors and electronic spectroscopy
310 Apr. 27, 2017 (Thu) 4:00 pm  Seminar Room(#1323, E6-2)  Prof.Donghan Lee (Chungnam National Univ.)  반도체 양자점을 이용한 단광자 광원
309 Apr. 28 (Fri.), 02:30 PM  E6-2. 1st fl. #1323  Dr. JeongYoung Park Graduate School of EEWS, KAIST  Hot electron generation at surfaces and its impact to catalysis and renewable energy conversion
308 Apr. 28 (Fri.), 04:00 PM  #1323 (E6-2. 1st fl.)  Dr. Minkyung Jung Research Institute, DGIST  Carbon nanotubes coupled to superconducting impedance matching circuits
307 Apr. 28 (Thu.) 3PM  #2501(E6-2. 2nd fl.)  Dr. Chang Hee Sohn, SEOUL NATIONAL UNIVERSITY  Lattice/Spin/Charge Coupling in 5d Pyrochlore Cd2Os2O7
306 Apr. 5 (Tue.), 4PM  E6-2. 1st fl. #1322  Dr. Ara Go, Columbia University  A new impurity solver for multi-orbital systems: adaptive truncation of the Hilbert space
305 Apr. 9 (Fri.), 10:00 AM  Zoom webinar  Prof. Marko Loncar (Harvard University, USA)  Integrated Lithium Niobate Photonics file
304 Apr.19 (Fri.), 11:00 AM  #1323, E6-2  Dr. Ji-Sang Park  First-principles studies of semiconductors for solar cell applications file