|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, (firstname.lastname@example.org)
Center for Quantum Coherence in Condensed Matter, KAIST
|공지||2019/09/18 - 12/5||Seminar Room #1323||Prof. David Schuster and etc.||Fall 2019: Physics Seminar Serises|
|공지||2019/09/02 - 12/09||Seminar Room 1501||이호성 박사 (한국표준과학연구원) and etc.||Fall 2019: Physics Colloquium|
|246||October 17 (Thu.), 16:00 PM||#1323, E6-2||Prof. Namkyoo Park||Top down manipulation of Waves : From Metamaterials, Correlated Disorder, Quantum Analogy, to Digital Processing|
|245||DEC. 27 (Thu), 04:00 PM||E6-2. 1st fl. #1323||Prof. Na Young Kim||Quantum Innovation (QuIN) Laboratory|
|244||June 4 (Tue.), 5:00 PM||#1323, E6-2||Prof. Minsu Kim||Stochastic nature of bacterial eradication using antibiotics|
|243||2015/06/03, 12PM||Room 101, E11||Prof. Min-Kyo, Seo & Hansuek, Lee(KAIST)||The First Wednesday Multidisciplinary Forum|
|242||Nov. 10th(Thu) 4 p.m.||E6-2. #1323(1st fl.)||Prof. Min Seok Jang, Electrical Engineering, KAIST||Low Dimensional Active Plasmonics and Electron Optics in Graphene|
|241||2018년 9월 7일 (금), 3PM||학술문화관 (E9), 2층 양승택 오디토리움||Prof. Martin Head-Gordon, UC Berkeley||Recent developments in density functional theory: From new functionals to the nature of the chemical bond|
|240||Apr. 9 (Fri.), 10:00 AM||Zoom webinar||Prof. Marko Loncar (Harvard University, USA)||Integrated Lithium Niobate Photonics|
|239||Apr. 19(Tue.), 2PM||#1323(E6-2. 1st fl.)||Prof. Mark Koepke, Department of Physics and Astronomy, West Virginia University, USA||Nonlocal collisional electron transport in partially ionized plasma generation, structure, and stability|
|238||November 28 (Thu.), 16:00 PM||#1323, E6-2||Prof. Kyung Taec Kim||Generation of coherent EUV emissions using ultrashort laser pulses|
|237||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|
|236||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|
|235||February 12(Web.)||E6-2, #5318||Prof. Kunio Kaneta||From inflation to new weak-scale|
|234||October 24 (Wed.), 10:30 AM||E6-1, Lecture Room 1501(1F)||Prof. Kerry J. Vahala||Photonic integration of next-generation clocks and Hertz-absolute-accuarcy optical frequenncy synthesizers|
|233||June 14 (THU), 10:00 AM||E6-2, 2nd fl. #2502||Prof. Kenji Toyoda||Phonons and polariton-like particles in trapped ions for quantum computation and quantum simulation|
|232||DEC. 16~18 (Sun~Tue)||E6-2. 1st fl. #1323||Prof. Keisuke Totsuka||Lectures on 2d Conformal Field Theory|
|231||MAR. 26 (TUE), 0300 PM||E6-2. 2st fl. #2501||Prof. Jung Hoon Han||Consideration of thermal Hall effect in frustrated and un-frustrated quantum magnets|
|230||October 11 (Thu.), 16:00 PM||#1323, E6-2||Prof. Joung-Real Ahn||Dirac electrons in a graphene quasicrystal|
|229||October 29 (Tue.), 14:30 PM||#1323, E6-2||Prof. Jörg Wrachtrup||Quantum sensing|
|228||May 2 (Thu.), 4:00 PM||#1323, E6-2||Prof. Joon Ik Jang||Anomalous optical properties of halide perovskites|
|227||April 11 (Thu.), 16:00 PM||#1323, E6-2||Prof. Joo-Hyoung Lee, GIST||Massive screening for cathode active materials using deep neural network|