|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
|108||May 31 (Tue.) 4 PM||#1323(E6-2, 1st fl.)||Dr. Kimin Kim, KAIST||Understanding 3D tokamak physics towards advanced control of toroidal plasma|
|107||Apr. 01 (Fri.) 2:30 PM||E6-2. 1st fl. #1501||Dr. KICHEON KANG, Chonnam National University||Interference of single charged particles without a loop and dynamic nonlocality|
|106||Nov. 11th(Fri), 1:30 p.m.||#1323(E6-2. 1st fl.)||Dr. Keun Su Kim, POSTECH||Bandgap Engineering of Black Phosphorus|
|105||Jun. 11 (Fri.), 04:00 PM||Online seminar||Dr. Keun Su Kim(Yonsei University)||Pseudogap in surface-doped black phosphorus|
|104||November 29 (Thu.), 16:00 PM||#1323, E6-2||Dr. Kee suk Hong||양자 칸델라 실현을 위한 단일 광자 발생장치 개발|
|103||Apr. 1(Fri.), 04:00 PM||Zoom webinar||Dr. Kayoung Lee (KAIST)||High-field Electron Transport and Interaction Induced Phenomena in 2D Materials|
|102||2015/11/24, 4PM||E6-2, #1323||Dr. Kab-Jin Kim (Institute for Chemical Research, Kyoto University, Japan)||Topology-based understanding of spin dynamics in inhomogeneously magnetized systems|
|101||Jul. 08 (Fri.) 2PM||#1323(E6-2. 1st fl.)||Dr. Junhyun Lee, Harvard University||Electronic quasiparticles in the quantum dimer model|
|»||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”|
|99||2015/12/17, 11:00AM||E4(KI Building), Matrix Hall (2nd fl.)||Dr. Jung-Hoon Park (Purdue University)||Wavefront engineering for in-vivo Deep brain imaging|
|98||June 27 (Wed.), 13:30 PM||#1323, E6-2||Dr. Jung Sik Park||Magnetic reversal of artificial spin ice|
|97||July. 14 (Fri.), 3:00 PM||#1323 (E6-2. 1st fl.)||Dr. Jun Hyun Lee / University of Maryland||Chiral anomaly in disordered Weyl semimetals|
|96||Nov. 1 (Fri.), 04:00 PM||E6-2. 1st fl. #1323||Dr. Ju-Jin Kim||Electron transport through weak-bonded contact metal with low dimensional nano-material|
|95||Sep. 27 (Fri.), 02:30 PM||E6-2. 1st fl. #1323||Dr. Joon Sue Lee||Spin-charge conversion in topological insulators for spintronic applications|
|94||Dec. 7 (Fri.), 04:00 PM||E6-2. 1st fl. #1323||Dr. Joon Ho Jang||Novel probes of interacting electrons in 2D systems|
|93||October 19 (Fri.), 10:00 AM||#1323, E6-2||Dr. Jongsoo Yoo||Energy conversion processes during magnetic reconnection in a laboratory plasma|
|92||Nov. 04 (Fri), 1:30 PM||E6-2. #1323(1st fl.)||Dr. Jonghyun Song, Department of Physics, Chungnam National University||Exotic phenomena at oxide LaAlO3/SrTiO3 hetero-interface and their applications|
|91||2015/08/03,10:30AM||E6-2, #1323 (Seminar Room)||Dr. Jonghee Yoo (Fermi National Accelerator Laboratory, USA )||Axion Search|
|90||Apr. 01 (Fri.) 4:15 PM||E6-2. 1st fl. #1501||Dr. JONG SOO LIM, KIAS||Cotunneling drag effect in Coulomb-coupled quantum dots|
|89||December 3 (Tue.), 4:00 PM||#1323, E6-2||Dr. Jong Mok Ok||Toward Quantum Materials with Correlated Oxides|