|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
|공지||Sep.22 2022||E6-1 #1323||2022 가을학기 응집물리 및 광학 세미나 전체 일정|
|56||Sep. 22 (Fri.), 04:00 PM||E6-2. 1st fl. #1323||Dr. GilHo Lee / Department of Physics, POSTECH||Unexpected Electron-Pairing in Integer Quantum Hall Effect|
|55||Sep. 22 (Fri.), 02:30 PM||E6-2. 1st fl. #1323||Dr. GilHo Lee / Department of Physics, POSTECH||Quantum Electronic Transport in Graphene Hybrid Nanostructures|
|54||October 25 (Thu.), 4:00 PM||#1323, E6-2||Dr. Gang Li||Abelian and non-Abelian dark photons|
|53||Nov. 1st (Tue), 10:30AM||#1323(E6-2 1st fl.)||Dr. Gadi Eisenstein, Technion||Time scale dependent dynamics in InAs/InP quantum dot gain media|
|52||April 4, 2016 (Mon) - April 8, 2016 (Fri)||KAIST Natural Science Building (E6-2), RM #4314||Dr. Fritz Caspers (CERN)||Radio frequency engineering|
|51||May 24 (Tue) 4 PM||E6-2. #1323(1st fl.)||Dr. Euyheon Hwang, SKKU Advanced Institute of Nanotechnology, Sung Kyung Kwan University||Electronic and magnetic properties of 2D transition-metal thiophosphates and tunability of magnetic order with carrier density|
|50||Jun. 2 (Fri.), 02:30 PM||E6-2. 1st fl. #1323||Dr. Euyheon Hwang(황의헌)||Quasiparticle Interference and Fourier transform scanning tunneling spectroscopy in WTe2 (Weyl semimetal)|
|49||Sep. 22 (Fri.), 01:00 PM||E6-2. 1st fl. #1323||Dr. EunSeong Kim / Department of Physics, KAIST||Superconductor-metal-insulator transition in thin Tantalum films|
|48||Jul. 07 (Thu.) 2PM||#1323(E6-2. 1st fl.)||Dr. Eun Ah Kim, CORNELL UNIV.||Let there be topological superconductors|
|47||2015/08/04, 11PM||B501, Room Red, KI bldg. 5nd fl.||Dr. Eric Jin Ser Lee(Univ. of Manitoba, Canada)||Propagation of ultrasound through two- and three-dimensional strongly scattering media|
|46||July 2, 2020 (Thursday)||Zoom Video Conference Seminar||Dr. Emmanuel Flurin (CEA Saclay)||An irreversible qubit-photon coupling for the detection of itinerant microwave photons|
|45||October 18 (Thu.), 10:00 AM||#1323, E6-2||Dr. Duyoung Min||Understanding membrane protein folding using single-molecule force techniques|
|44||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|
|43||#1323(E6-2. 1st fl.)||Jul. 10th (Mon), 4pm||Dr. Duk Young Kim Los Alamos National Laboratory||“Intertwined Orders in a Heavy-fermion metal”|
|42||Nov. 20 (Fri.), 02:30 PM||Online||Dr. Doohee Cho||Lumpy Cooper pairs in an iron-based superconductor|
|41||Nov. 9 (Fri.), 04:00 PM||E6-2. 1st fl. #1323||Dr. Donghun Lee||Quantum sensing and imaging with diamond defect centers for nano-scale spin physics|
|40||Jan. 17(Mon) - 21 (Fri), 2-4pm||E6-2 Room 2502||Dr. Donghui Jeong (Penn State University)||Five Lectures on Observational Probes of Dark Energy|
|39||Nov. 04 (Fri), 3:00 PM||E6-2. #1323(1st fl.)||Dr. Dohun Kim, Department of Physics and Astronomy, SNU||Quantum information experiments using few electron spins in semiconductors|
|38||Nov. 20 (Fri.), 04:00 PM||Online||Dr. Dohun Kim||Coherent control of field gradient induced quantum dot spin qubits|
|37||Mar 2 (Tue.), 16:00||Online||Dr. Dmitry Svintsov||Sensitive terahertz detection with graphene-based transistors|