|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|
|244||Oct. 27th(Thu) 4PM||#1323(E6-2)||Dr. 이 강 희, KAIST, Mechnical Engineering||Terahertz Metal Optics|
|243||Oct. 25 (Fri), 15:00 ~||#1323, E6-2||Daesu Lee,Junwoo Son,MyungJoon Han ,Siheon Ryee,Eun-Gook Moon||Physics Seminar|
|»||Oct. 18 (Tue.), 3PM||E6-2. 1st fl. #1323||Dr. JunHo Suh, Korea Research Institute of Standards and Science||“Hybrid quantum systems with mechanical oscillators”|
|241||Oct. 18 (Tue.), 1:30 PM||1st fl. #1323(E6-2)||Dr. Chan-Ho Yang, Department of Physics, KAIST||"Visualization of oxygen vacancy in motion and the interplay with electronic conduction"|
|240||Oct. 17th (Mon) 11:00 AM||#1323,(E6-2, 1st fl.)||Nguyen Quang Liem, Institute of Materials Science, VAST, Viettnam||IMS and examples of the studies on optoelectronic materials|
|239||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|
|238||Oct. 12 (Fri.), 02:30 PM||E6-2. 1st fl. #1323||Dr. Daniel Kyungdeock Park||Quantum Advantage in Learning Parity with Noise|
|237||Oct. 10(Tue) 4PM||E6-2 #1323||김성웅 교수 (성균관대학교 에너지과학과)||Discovery of New 2D Materials with Diverse Physical Properties|
|236||Oct. 07 (Fri), 4:00 PM||E6-2. #1323(1st fl.)||Dr. Choong Hyun Kim,IBS-CCES, Seoul National University||“Tilt engineering of 4d and 5d transition metal oxides?”|
|235||Oct. 07 (Fri), 1:30 PM||E6-2. #1323(1st fl.)||Dr. Suk Bum Chung, IBS-CCES , Seoul National University||“Symmetry and topology in transition metal dichalcogenide?”|
|234||November 8 (Thu.), 16:00 PM||#1323, E6-2||이종완 박사||Conformality lost|
|233||November 7 (Thu.), 16:00 PM||#1323, E6-2||Prof. Je-Hyung Kim||Integrated quantum photonics with solid-state quantum emitters|
|232||November 5 (Tue.), 4:00 PM||#1323, E6-2||Dr. Shik Shin||Study on nanomaterials by the development of ultrahigh resolution laser-photoelectron microscopy (PEEM)|
|231||November 29 (Thu.), 16:00 PM||#1323, E6-2||Dr. Kee suk Hong||양자 칸델라 실현을 위한 단일 광자 발생장치 개발|
|230||November 28 (Thu.), 16:00 PM||#1323, E6-2||Prof. Kyung Taec Kim||Generation of coherent EUV emissions using ultrashort laser pulses|
|229||November 21 (Wed.), 15:00 PM||#1323, E6-2||Prof. Seongshik Oh||Engineering topological quantum physics at the atomic scale|
|228||November 20 (Wed.), 4:00 PM||#5302, E6-2||Dr. Shigeyuki Ishida||Correlation between superconducting transition temperature and critical current density in irradiated iron-based superconductors|
|227||November 14 (Thu.), 16:00 PM||#1323, E6-2||Prof. Ji-Hun Kang||Semi-classical model of polariton propagation|
|226||November 1 (Thu.), 16:00 PM||#1323, E6-2||Dr. KyeoReh Lee||Direct holography from a single snapshot|
|225||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|