visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2022-12-09 11:00 
일시 Dec. 9 (Fri), 11:00AM 
장소 E6-2 #1323 
연사 김도헌(서울대 물리천문학부 교수) 
세미나 영상은 아래 링크로 확인 바랍니다. (공개기간: 2022.12.15-2023.03.14, 3개월)
 
 
1. Date / Time 
    - Dec  9, 2022
    - 11:00 AM (KST)
 
2. Place: E6-2 #1323
 
3. Speaker
    - 김도헌 (서울대 물리천문학부 교수)
 
4. Talk Title
    - Two-electron quantum dot spin qubits in isotopically purified silicon
 
5. Abstract
Engineered spin-electric coupling is essential to enable fast manipulation of spins in semiconductor quantum dot (QD) nanostructures, especially in silicon. Although the placement of on-chip micromagnets has enabled single-spin qubits in silicon with gate fidelity to reach surface code-based error correction threshold, corresponding results using encoded spin qubits, for example, single-triplet qubits with high-quality quantum oscillations, have not been demonstrated. Instead, the spin-valley coupling has been recently used to enhance the electrical controllability of two-electron spin qubits in silicon at the expense of increased susceptibility to charge noise. Here, we demonstrate fast singlet-triplet qubit oscillation (~ 100MHz) of a quantum dot spin qubit in isotopically purified 28Si/SiGe substrate with an on-chip micromagnet in the regime where valley-splitting in each quantum dot exceeds 300 ueV. Combining rf-reflectometry-based single-shot readout and real time Hamiltonian estimation, we show that the oscillation quality factor of an encoded spin qubit over 1000 can be achieved. We further present the measurement of single-triplet qubit oscillation and variation of coherence time near the micro-magnet’s magnetization reversal, offering a route to in-situ tune magnetic field gradient and hence the Larmor frequency of the singlet-triplet qubit in silicon.
 
Attached: C.V
 
Inquiry: Prof. Se Kwon Kim(sekwonkim@kaist.ac.kr) / Prof. Hee Jun Yang (h.yang@kaist.ac.kr)
 
번호 날짜 장소 제목
522 2016-04-26 16:00  #1323(1st Floor. E6-2)  Transport spectroscopy for electronic bands in carbon-based nanomaterials with weak-bond contacts
521 2016-11-1 10:30  #1323(E6-2 1st fl.)  Time scale dependent dynamics in InAs/InP quantum dot gain media
520 2016-06-01 16:00  #1323(E6-2 1st fl.)  Laboratory experiments relevant to mesospheric clouds, Saturn’s rings & astrophysical jets
519 2016-10-27 16:00  #1323(E6-2)  Terahertz Metal Optics
518 2016-05-19 16:00  #1323(E6-2, 1st fl.)  Nonlinear/quantum optical effect in silicon nano-photonics
517 2016-06-16 16:00  #1323(E6-2, 1st fl.)  Quantum information processing using quantum dots and photonic crystal cavities
516 2016-09-22 15:30  #1323(E6-2, 1st fl.)  Polarized 3He, Polarized Neutrons and New Interactions beyond the Standard Model
515 2016-05-31 16:00  #1323(E6-2, 1st fl.)  Understanding 3D tokamak physics towards advanced control of toroidal plasma
514 2016-09-22 15:30  #1323(E6-2, 1st fl.)  Polarized 3He, Polarized Neutrons and New Interactions beyond the Standard Model
513 2016-05-16 16:00  #1323(E6-2, 1st Fl.)  Tuning microwave cavities with biased nonlinear dielectrics for axion searches
512 2016-12-09 16:00  #1323(E6-2. 1st fl.  Shift Charge and Spin Photocurrents in Dirac Surface States of Topological Insulator
511 2016-04-19 14:00  #1323(E6-2. 1st fl.)  Nonlocal collisional electron transport in partially ionized plasma generation, structure, and stability
510 2016-12-8 16:00  #1323(E6-2. 1st fl.)  Dynamical Resonance between Two Optical Cavities via Optomechanical Oscillator
509 2017-03-02 16:00  #1323(E6-2. 1st fl.)  “Progress in the comparison of ARPES to DMFT for d and f strongly correlated electron systems”
508 2016-07-08 14:00  #1323(E6-2. 1st fl.)  Electronic quasiparticles in the quantum dimer model
507 2016-07-28 16:00  #1323(E6-2. 1st fl.)  Low Dimensional Electrons: On the Road to Hybrid Quantum Systems
506 2016-12-09 13:30  #1323(E6-2. 1st fl.)  Entanglement area law in strongly-correlated systems
505 2016-11-24 16:00  #1323(E6-2. 1st fl.)  Harmonic oscillator physics with single atoms in a state-selective optical potential
504 2016-11-29 16:00  #1323(E6-2. 1st fl.)  Symmetry Protected Kondo Metals and Their Phase Transitions
503 2016-11-11 16:00  #1323(E6-2. 1st fl.)  Dirac fermions in condensed matters