|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|
|292||#1323(E6-2. 1st fl.)||Jul. 10th (Mon), 4pm||Dr. Duk Young Kim Los Alamos National Laboratory||“Intertwined Orders in a Heavy-fermion metal”|
|291||-||RM. 1323, E6-2||Spring 2019: Physics Seminar Serises|
|290||2009/02/23-05/04||E6, 1501||안종현교수(성균관대) 외||Physics Colloquium : 2009 Spring|
|289||2009/09/07-11/30||E6, 1501||이주영박사(KIAS) 외||Physics Colloquium : 2009 Fall|
|288||2009/10/21, 4PM||E6, 1501||최석봉교수(서울대)||Interdimensional Universality of Dynamic Interfaces|
|287||2010/02/08-05/03||E6, 1501||최인수교수(서울대) 외||Physics Ciolloquium : 2010 Spring|
|286||2010/02/14-05/09||E6, 1501||황철주(주성엔지니어링 사장) 외||Physics Colloquium - 2011 Spring|
|285||2010/09/06-12/06||E6, 1501||조호진기자(조선일보) 외||Physics Colloquium : 2010 Fall|
|284||2011/05/16, 4PM||E6, 1501||서민교교수(KAIST)||Photonics with surface plasmon polaritons|
|283||2011/09/03-12/06||E6, 1501||김용균교수(한양대) 외||Physics Colloquium : 2011 Fall|
|282||2012/02/13-05/14||E6, 1501||Kenji Ohmori (Photo-Molecular Science, IMS)||Physics Colloquium : 2012 Spring|
|281||2012/04/02, 4PM||E6, 1501||Yong Hee Jeong||A new route to ferroelectricity in magnetic spinels: a case of Co2MnO4|
|280||2013/03/11-06/10||E6, 1501||강명수교수(KAIST) 외||Physics Colloquium : 2013 Spring|
|279||2013/09/09-12/09||E6, 1501||박혁규교수(부산대) 외||Physics Colloquium : 2013 Fall|
|278||2014/03/10-06/09||E6, 1501||신용일교수(서울대)||Physics Colloquium : 2014 Spring|
|277||2014/05/28, PM5||KI Building, Matrix Hall||이웅범 대표이사(LG이노텍)||부품소재산업이 미래다|
|276||2014/12/22, 2PM||E6, Rm1319||Prof. Changbong Hyeon (KIAS)||Dynamics of molecular motors: Power stroke vs Brownian ratchet|
|275||2015/03/04, 12PM||1323호, E6-2||Prof. Choi Hak-Soo(Harvard)||Bioimaging and Biosensing Using Near-Infrared Fluorescence|