|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|
|250||July 27, 2018 at 15:00||Room 5318, KAIST Natural Sciences Lecture Hall(E6).||Dr. Hyejung Kim(Technische University Dresden)||Muon g-2 in the 2HDM and MSSM: comprehensive numerical analysis and absolute maxima|
|249||Oct. 12 (Fri.), 04:00 PM||E6-2. 1st fl. #1323||Dr. HyungWoo Lee||Direct observation of a two-dimensional hole gas at oxide interfaces|
|248||Dec. 26 (Wed.), 04:00 PM||E6-2. 1st fl. #1323||Dr. Isaac H. Kim||Brane-like defect in 3D toric code|
|247||July 31(Wed.)/ 16:00||E6-2, #1323||Dr. Ivan Borzenets||Features of ballistic superconducting graphene|
|246||Thursday, July 12, 2018 at 17:00||Room 5318, KAIST Natural Sciences Lecture Hall(E6)||Dr. Jae Hyeok Yoo (University of California, Santa Barbara, Department of Physics)||The MilliQan Experiment: Search for Milli-Charged Particles at the LHC|
|245||Dec. 9(Fri), 1:30 p.m.||#1323(E6-2. 1st fl.)||Dr. Jae Yoon Cho, POSTECH||Entanglement area law in strongly-correlated systems|
|244||October 16 (Wed), 4:00pm||#1323 (E6-2, 1st fl.)||Dr. Jaewon Song||Emergent black holes and monopoles from quantum fields|
|243||Nov. 24(Thu) 4p.m.||#1323(E6-2. 1st fl.)||Dr. Jai-Min Choi, Chonbuk National Univiersity||Harmonic oscillator physics with single atoms in a state-selective optical potential|
|242||2015/09/07, 3PM||E6-2. 1st fl. #1318||Dr. Jasbinder Sanghera (U.S. Naval Research Laboratory (NRL))||Advanced Optical Materials and Devices at NRL|
|241||Apr. 12 (Tue.), 4 PM||E6-2. 1st fl. #1323||Dr. Jeehoon Kim, POSTECH||Confinement of Superconducting Vortices in Magnetic Force Microscopy|
|240||Apr. 28 (Fri.), 02:30 PM||E6-2. 1st fl. #1323||Dr. JeongYoung Park Graduate School of EEWS, KAIST||Hot electron generation at surfaces and its impact to catalysis and renewable energy conversion|
|239||2015/12/11, 3:45PM||E6-2, #1323||Dr. Ji Hun Sim (POSTECH)||Dynamical mean field theory studies on heavy fermion system|
|238||Apr.19 (Fri.), 11:00 AM||#1323, E6-2||Dr. Ji-Sang Park||First-principles studies of semiconductors for solar cell applications|
|237||Sep. 27 (Fri.), 04:00 PM||E6-2. 1st fl. #1323||Dr. Jindong Song||0D/1D/2D/3D III-V materials grown by MBE for Optelectronics|
|236||Mar. 16 (Fri.), 02:30 PM||E6-2. 1st fl. #1323||Dr. JinHee Kim||산화물 다층박막에서의 다양한 물리현상|
|235||Dec. 8(Thu) 4p.m.||#1323(E6-2. 1st fl.)||Dr. Jinhyoung Lee, Hanyang University||Dynamical Resonance between Two Optical Cavities via Optomechanical Oscillator|
|234||Mar. 2nd (Thu), 4:00 p.m||#1323(E6-2. 1st fl.)||Dr. Jonathan Denlinger, Lawrence Berkeley National Lab||“Progress in the comparison of ARPES to DMFT for d and f strongly correlated electron systems”|
|233||December 3 (Tue.), 4:00 PM||#1323, E6-2||Dr. Jong Mok Ok||Toward Quantum Materials with Correlated Oxides|
|232||Apr. 01 (Fri.) 4:15 PM||E6-2. 1st fl. #1501||Dr. JONG SOO LIM, KIAS||Cotunneling drag effect in Coulomb-coupled quantum dots|
|231||2015/08/03,10:30AM||E6-2, #1323 (Seminar Room)||Dr. Jonghee Yoo (Fermi National Accelerator Laboratory, USA )||Axion Search|