visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2022-05-25 14:00 
일시 May. 25th (Wed), 14:00 
장소 E6 Room(#2501) 
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 날짜 장소 제목
261 2024-01-03 11:00  E6-2, #1323  Interplay of Strong Correlations, Topology, and Disorder in 2D Quantum Matters
260 2024-06-12 16:00  E6-2, #1323  New high Tc superconductivity and symmetric pseudogap metal in the bilayer nickelate La3Ni2O7-Part2 file
259 2024-01-16 14:00  E6-2, #1323  Dimer Physics and Superconductivity in La3Ni2O7
258 2023-07-18 11:00  E6-2, #1323  Non-Hermitian Casimir Effect of Magnons
257 2023-07-12 11:00  E6-2, #1323  Study of spin-1/2 antiferromagnetic kagome Heisenberg model by symmetric projected entangled simplex states
256 2023-06-08 16:00  E6-2, #1323  Thermal decoupling in high-Tc cuprate superconductors
255 2023-12-19 16:00  E6-2, #1323  [High Energy Theory Seminar] Non-invertible symmetries, leptons, quarks, and why multiple generations
254 2023-07-19 16:00  E6-2, #1323  [High-Energy Theory Seminar]Deriving the Simplest Gauge-String Duality
253 2023-07-11 11:00  E6-2, #1323  Ordered phases, non-Fermi liquid, and quantum criticality driven by entanglement between multipoles and conduction electrons
252 2015-11-24 16:00  E6-2, #1323  Topology-based understanding of spin dynamics in inhomogeneously magnetized systems
251 2015-11-28 10:00  E6-2, #1323  Electron Tunneling Spectroscopy of Single and Bilayer Graphene with Hexagonal Boron Nitride as Tunneling Barrier
250 2015-11-19 16:00  E6-2, #1323  Emergent Collective Phenomena and Functions at Reduced Dimensions
249 2015-12-11 13:30  E6-2, #1323  Quantum spin liquid in the 1/3 depleted triangular lattice Ba3(Ru1-xIrx)Ti2O9
248 2016-09-29 16:00  E6-2, #1323  2016 Fall, Physics Seminar Serises file
247 2016-01-11 16:00  E6-2, #1323  Mott Physics in the Strong Spin-Orbit Coupling Regime
246 2015-12-03 16:00  E6-2, #1323  Hybrid solid state spin qubits in wide bandgap semiconductors
245 2015-11-10 16:00  E6-2, #1323  Rapid heating of matter using high power lasers
244 2015-11-23 13:30  E6-2, #1323  What's Beyond the Standard Model? Lessons from Run I and what might come in Run II
243 2019-07-31 16:00  E6-2, #1323  Features of ballistic superconducting graphene file
242 2019-06-24 11:00  E6-2, #1323  Topological photonic anomalies file