|일시||May. 13 (Fri.), 02:30 PM|
|연사||Dr. Kun-Rok Jeon(Department of Physics, Chung-Ang University)|
“Topological Superconducting Spintronics Towards Zero-Power Computing Technologies”
Dr. Kun-Rok Jeon
Department of Physics, Chung-Ang University
May. 13 (Fri.), 02:30 PM
Semiconductor (SC) spintronics [1-4] aims to integrate memory and logic functions into a single device. Ferromagnetic tunnel contacts have emerged as a robust and technically viable method to inject spin current into a SC up to room temperature, and to detect it [3-7]. Intriguingly, it has been established that the spin current in ferromagnetic tunnel contacts can be created by thermal means (driven by a heat flow), namely Seebeck spin tunneling . So far, the creation of thermal spin current relies on the spin-dependent energy dispersion of electronic states around the Fermi energy (EF), which determines thermoelectric properties. In the first part of my talk, I will describe a conceptually new approach to tailor the thermal spin current in ferromagnetic tunnel contacts to SCs exploiting spin-dependent thermoelectric properties away from EF through the application of a bias voltage across the tunnel contact [9,10].
Combining superconductivity with spintronics brings in a variety of notable phenomena which do not exist in the normal state, for instance quantum coherence, superconducting exchange coupling and spin-polarized triplet supercurrents [11,12]. This nascent field of superconducting spintronics promises to realize zero-energy-dissipation spin transfer and magnetization switching. Recent equilibrium (zero-bias) studies of the Josephson effect in S/FM/S (FM: ferromagnet; S: Superconductor) junctions and the critical temperature Tc modulation in FM/S/FM and S/FM/FM' superconducting spin valves have demonstrated that engineered magnetically-inhomogeneous S/FM interfaces can generate long-range triplet pairing states which explicitly carry spin [11,12]. However, direct measurement of triplet spin transport through a singlet S has not so far been achieved. In the second part, I will describe an essentially different approach, namely, a time-dependent ferromagnetic magnetization [ferromagnetic resonance (FMR)] can drive spin-polarized transport in a singlet S via spin-triplet states induced by spin-orbit coupling [13,14].
If time permits, I will briefly outline outstanding technical issues for the realization of energy-efficient (or even dissipation-less) spintronic technologies and present my research direction of how to address these issues via topology physics [15,16].
Reference:  Rev. Mod. Phys. 80, 1517 (2008),  Rev. Mod. Phys. 76, 323 (2004),  Nat. Mater. 11, 400 (2012),  Semicond. Sci. Technol. 27, 083001 (2012),  Nature 462, 491 (2009),  Appl. Phys. Express 4, 023003 (2011),  Phys. Rev. Appl. 2, 034005 (2014),  Nature 475, 82 (2011),  Nat. Mater. 13, 360 (2014),  Phys. Rev. B 91, 155305 (2015),  Nat. Phys. 11, 307 (2015),  Rep. Prog. Phys. 78, 104501 (2015),  Nat. Mater. 17, 499 (2018),  Phys. Rev. X 10, 031020 (2020),  Nat. Mater. 20, 1358 (2021),  Under review in Nat. Nanotech. (2022).
Contact: SunYoung Choi, (firstname.lastname@example.org)
Center for Quantum Coherence in Condensed Matter, KAIST
|302||May. 25th (Wed), 14:00||E6 Room(#2501)||Dr. Duk-Hyun Choe(Samsung Advanced Institute of Technology)||Atomic-level insights into ferroelectric switching and preferred orientation of ultrathin hafnia|
|301||May. 25(Wed), 4pm||E6-2. 1st fl. #1323 / Zoom||Dr. Sungwoo Hong (Enrico Fermi Institute at University of Chicago)||Uncovering New Lampposts for Dark Matter: Continuum or Conformal|
|300||May. 19(Thu), 4pm||E6-2. #1323 & Zoom||Dr.Jay Hyun Jo (Yale University, Department of Physics)||Chasing Long Standing Neutrino Anomalies with MicroBooNE|
|299||May. 18(Wed), 4pm||E6-2. #1323 & Zoom||Dr.Heeyeon Kim (Rutgers University, Department of Physics and Astronomy)||Geometry, Algebra, and Quantum Field Theory|
|298||May. 17(Mon) 17:00||Zoom webinar||Jing Shi (UC Riverside, USA)||Spin current generation and detection in uniaxial antiferromagnets|
|297||May. 17 (Thu.), 01:30 PM||E6-2. 1st fl. #1323||Prof. Yong-Baek Kim University of Toronto||Quantum Spin Liquid in Kitaev Materials|
|296||May. 14 (Fri.), 04:00 PM||Online seminar||Dr. Je-Hyung Kim(UNIST)||Spatial and temporal separation of environmental dephasing sources from solid-state quantum emitters|
|295||May. 14 (Fri.), 02:30 PM||Online seminar||Dr. Suyong Jung(KRISS)||Electrically tunable spin valve effect in vertical van-der-Waals magnetic tunnel junctions|
|294||May. 13 (Fri.), 04:00 PM||자연과학동(E6-2) 1st fl. #1323||Dr. Yosep Kim(Center for Quantum Information, KIST)||High-fidelity iToffoli gate for fixed-frequency superconducting qubits|
|»||May. 13 (Fri.), 02:30 PM||Zoom webinar||Dr. Kun-Rok Jeon(Department of Physics, Chung-Ang University)||Topological Superconducting Spintronics Towards Zero-Power Computing Technologies|
|292||May. 12(Thu), 4pm||E6-2. #1323 & Zoom||Dr.Philip Chang (University of California San Diego, Department of Physics)||New frontiers of electroweak physics at the LHC|
|291||May. 12 (Fri.), 01:30 PM||E6-2. 1st fl. #1323||Dr. Young Kuk Kim||Topological Dirac insulator|
|290||May. 11(Wed), 4pm||E6-2. #1323 & Zoom||Dr. Sunok Josephine Suh (Kavli Institute for Theoretical Physics)||Gravity as a phenomenon in quantum dynamics|
|289||May. 11 (Fri.), 04:00 PM||E6-2. 1st fl. #1323||Dr. Nam Kim||암페어 단위 재정의와 단전자 펌프 소자 개발|
|288||May. 11 (Fri.), 02:30 PM||E6-2. 1st fl. #1323||Dr. Kun Woo Kim||Disordered Floquet topological insulators|
|287||May 9 (Wed.), 04:00 PM||#1323, E6-2||Prof. Jong-Soo Rhyee||Recent advances in thermoelectric bulk composites|
|286||May 9 (Thu.), 16:00 PM||#1323, E6-2||Prof. Kwang Geol Lee||Quantum Optical Sensing Using Single Photons And Single Photon Emission from Single Emitters|
|285||May 9 (Thu.), 16:00 PM||#1323, E6-2||Prof. Kwang Geol Lee||Quantum Optical Sensing Using Single Photons And Single Photon Emission from Single Emitters|
|284||May. 8th (Wed), 16:00||E6 Room(#1323)||Jieun Lee||Imaging valley dependent electron transport in 2D semiconductors|
|283||May 311 (Thu.), 04:00 PM||#1323, E6-2||Prof. Teun-Teun Kim||Dynamic control of optical properties with gated-graphene metamaterials|