|장소||E6-2. 1st fl. #1323|
|일시||Oct. 18 (Tue.), 3PM|
|연사||Dr. JunHo Suh, Korea Research Institute of Standards and Science|
“Hybrid quantum systems with mechanical oscillators”
Dr. JunHo Suh, Korea Research Institute of Standards and Science
Oct. 18 (Tue.), 3PM, E6-2. 1st fl. #1323
Quantum machines are actively pursued to harness quantum coherence and entanglement as new resources for information processing and precision sensing. Among those activities, hybrid quantum systems are recognized as a promising platform for building multi-functional quantum machines by connecting quantum states in different physical domains, and mechanical oscillators are accepted as important components in the quantum hybrids. In this talk, I review recent examples of hybrid quantum systems involving mechanical oscillators strongly coupled to electrons and photons. In the first part, a quantum electro-mechanical system is introduced. A cooper-pair box qubit is electrostatically coupled to a nanomechanical oscillator. A dispersive measurement of qubit states is achievable through high-quality read-out of nanomechanical motion, which also maintains qubit coherence proved via microwave spectroscopy and Landau-Zener interference. In the second part, mechanical oscillators coupled to microwave photons, or "quantum opto-mechanical systems", are described, where radiation pressure mediates the interaction between photons and the mechanical oscillator. Photons act as a probe for mechanical motion in this case, and a fundamental limit in measurement sensitivity arises due to Heisenberg's uncertainty principle, as known as quantum standard limit(SQL). By carefully measuring mechanical motion in quadratures, we identify the fundamental back-action from photons which mandates SQL, and also demonstrate a novel scheme known as quantum non-demolition measurement (QND) which allows a precise measurement without back-action in one quadrature of motion. When the coupling between the microwave photons and mechanical motion is strong enough, the back-action from photons start modifying quantum noise in mechanical oscillators and produced mechanical quantum squeezed states[4,5]. Finally, it is expected that one could approach ultra-strong coupling regime as photon-mechanical oscillator coupling strength increases, where single photon coupled to mechanical motion dominates the hybrid system. Mechanical states in the ultra-strong coupling limit deviate from well-known number states which could open a new paradigm for controlling mechanical quantum states. A quantum dot system embedded in a nanowire is proposed to be a candidate to reach this interesting regime, and our recent progress toward this direction is dissussed.
 Kurizki et.al., PNAS 112, 3866-3873 (2015).
 LaHaye et.al., Nature 459, 960-964 (2009).
 Suh et.al., Science 344, 1262-1265 (2014).
 Wollman et.al., Science 349, 952-955 (2015).
 Lei et.al., PRL 117, 100801 (2016).
 Nation et.al., PRA 93, 022510 (2016).
Contact: SunYoung Choi, (email@example.com)
Center for Quantum Coherence in Condensed Matter, KAIST
|공지||2019/03/21 - 5/30||Seminar Room #1323||Dr. Hyangtag Lim (KIST) and etc.||Spring 2019: Physics Seminar Serises|
|공지||2019/02/25 - 06/03||Seminar Room 1501||양용수 교수 (Prof. Yongsoo Yang, KAIST) and etc.||Spring 2019: Physics Colloquium|
|111||DEC. 26 (Wed), 04:00 PM||E6-1. 3rd fl. #3434||Y. Kim, A. Go, K. Hwang and E.-G. Moon||Informal Workshop on Topology and Correlation|
|110||DEC. 16~18 (Sun~Tue)||E6-2. 1st fl. #1323||Prof. Keisuke Totsuka||Lectures on 2d Conformal Field Theory|
|109||Dec. 15 (Fri.), 9:20 AM||E6-2, Lecture Room #1323||Prof. Jhinhwan Lee 외 9명||Workshop on Magnetism in Unconventional Superconductors 개최|
|108||Dec. 13-14(Wed.-Thu.) 13:30 PM||자연과학동 대형강의실 (1501호)||장기주 교수 외 9명||KAIST-KIAS Joint Workshop in Theoretical Sciences 개최|
|107||Dec. 12th (Mon)||1:30p.m. #1323(E6-2. 1st fl.)||Dongjoon Song , AIST||“Possible symmetry in the phase diagrams of electron- & hole-doped cuprate high-Tc superconductors”|
|106||DEC. 11 (Tue), 04:00 PM||E6-2. 1st fl. #1323||Prof. Hiroshi Shinaoka||Natural compact representation of Matsubara Green’s functions: applications to analytic continuation and quantum many-body simulations|
|105||August 1, 2018 at 11:00AM||양분순 빌딩 (E16-1) 207호||이대열 교수, 예일대 석좌교수||Future of AI: Is the brain a computer?|
|104||Aug. 4, 2016 (Thu.), 2:30 pm||KAIST Natural Science Building (E6-5), EDU 3.0 Room(1st fl.)||Prof. Argyris Nicolaidis||Relational Logic (with applications to Quantum Mechanics, String Theory, Cosmology, Neutrino Oscillations, Statistical Mechanics)|
|103||AUG. 31 (Thu.), 2 PM||#5318(E6-2. 5th fl.)||Prof. Hiroaki Ishizuka (The University of Tokyo)||“Berry phase and nonlinear response: photocurrent in noncentrosymmetric insulators and Weyl semimetals”|
|102||Aug. 16 (Wed.), 4 PM||#1322 (E6-2. 1st fl.)||Prof. Noejung Park (UNIST)||Phonon-driven spin-Floquet valleytro-magnetism|
|101||April 6, 2017 (Thu), 4:00 pm||IBS CAPP seminar room, Creation Hall (3F), KAIST Munji Campus||Prof. Youngjoon Kwon (Yonsei University)||For whom the Belle tolls|
|100||April 6, 2016 (Wed), 3:30 PM||E6-2, RM #1323||Dr. Andrei Matlashov (Los Alamos National Laboratory)||Superconducting Quantum Interference Devices for Precision Detection|
|99||April 6 (Fri.), 10:00 AM||#2502, E6||박채연 박사||Entanglement and thermalization in many-body systems: recent progress|
|98||April 5th 2017, 12:00 ~ 13:00||Room 101, Creative Learning Bldg.(E11)||Prof. Wonho Choe(Dept. of Physics),Prof. Young-chul GHIM(Dept. of Nuclear & Quantum Engineering)||2017년 4월 첫수 융합포럼 개최 안내(물리학과 & 원자력 및 양자공학과 공동 개최)/The First Wednesday Multidisciplinary Forum in April 2017 organized by Dept. of Physics & Dept. of Nuclear & Quantum Engineering|
|97||April 4, 2016 (Mon) - April 8, 2016 (Fri)||KAIST Natural Science Building (E6-2), RM #4314||Dr. Fritz Caspers (CERN)||Radio frequency engineering|
|96||April 4 (Thu.), 16:00 PM||#1323, E6-2||Prof. Su-Hyun Gong||Chiral spin-photon interaction at nanoscale|
|95||April 26 (Tue), 4PM||#1323(1st Floor. E6-2)||Dr. Myung-Ho Bae, Korea Research Institute of Standards and Science||Transport spectroscopy for electronic bands in carbon-based nanomaterials with weak-bond contacts|
|94||April 26 (Fri.), 4:00 PM||#1323, E6-2||Dr. Soonwon Choi||Robust Quantum Metrology using Strongly Interacting Spin Ensembles and Quantum Convolutional Neural Network|
|93||April 23 (Tue.), 4:00 PM||#1323, E6-2||Prof. Johan Chang||From Mott physics to high-temperature superconductivity|
|92||April 13 (Fri.), 10am||#1323 (E6-2, 1st fl.)||Dr. Sungkun Hong||Quantum meets Mechanics: from Quantum Information to Fundamental Research|