|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||2018/09/20 - 11/29||Seminar Room #1323||손주혁 교수(서울시립대 물리학과) and etc.||Fall 2018: Physics Seminar Serises|
|공지||2018/08/27 - 12/03||Seminar Room 1501||김승중 교수 (KAIST) and etc.||Fall 2018: Physics Colloquium|
|208||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|
|207||Thursday, December 14, 2017 at 3:00 pm||Seminar Room (C303), Creation Hall (3F), KAIST Munji Campus||Chunglee Kim (KASI)||Exploring the Universe via GWs in the era of multi-messenger astronomy|
|206||September 5 (Wed.), 16:00 PM||#1323, E6-2||Dr. Dirk Wulferding||Shining a light on fractional excitations|
|205||September 20 (Thu.), 16:00||#1323, E6-2||Prof. Joo-Hiuk Son||Toward Cancer Treatment Using Terahertz Radiation: Demethylation of Cancer DNA|
|204||Sep. 4 (Tue), 02:30 PM||E6-2. 2st fl. #2502||Dr. Changmin Lee, MIT||Ultrafast time- and angle-resolved photoemission spectroscopy (tr-ARPES) with extreme ultraviolet laser pulses|
|203||Sep. 29th(Thu), 4PM||E6-2 #1323 (1st floor)||Dr. Sangyoon Han, Department of Physics, KAIST||Large-scale Silicon Photonic MEMS Switches|
|202||Sep. 29 (Thu), 4:00 PM||E6-2. #2501(2nd fl.)||Dr. Minu Kim, Institute for Basic Science, Seoul National University||Exploring the phase diagram of BaBiO3: epic voyage of just another bad trip?|
|201||Sep. 26 (Tue.), 11AM||#1323 (E6-2. 1st fl.)||Dr. Yukiaki Ishida / ISSP, University of Tokyo||Time-resolved ARPES study of Dirac and topological materials|
|200||Sep. 22, 2016(Thu), 3:30 PM||#1323(E6-2, 1st fl.)||Dr. Haiyang Yan (Institute of Nuclear Physics and Chemistry)||Polarized 3He, Polarized Neutrons and New Interactions beyond the Standard Model|
|199||Sep. 22, 2016(Thu), 3:30 PM||#1323(E6-2, 1st fl.)||Dr. Haiyang Yan (Institute of Nuclear Physics and Chemistry)||Polarized 3He, Polarized Neutrons and New Interactions beyond the Standard Model|
|198||Sep. 22 (Fri.), 04:00 PM||E6-2. 1st fl. #1323||Dr. GilHo Lee / Department of Physics, POSTECH||Unexpected Electron-Pairing in Integer Quantum Hall Effect|
|197||Sep. 22 (Fri.), 02:30 PM||E6-2. 1st fl. #1323||Dr. GilHo Lee / Department of Physics, POSTECH||Quantum Electronic Transport in Graphene Hybrid Nanostructures|
|196||Sep. 22 (Fri.), 01:00 PM||E6-2. 1st fl. #1323||Dr. EunSeong Kim / Department of Physics, KAIST||Superconductor-metal-insulator transition in thin Tantalum films|
|195||Sep. 13 (Wed.), 4 PM||#1323 (E6-2. 1st fl.)||Prof. Yi. Zhou (The Zhejiang Univ.)||An Introduction to Quantum Spin Liquids|
|194||Sep. 12 (Tue.), 4 PM||#1323 (E6-2. 1st fl.)||Prof. Yi. Zhou (The Zhejiang Univ.)||Exact Solution for the Interacting Kitaev Chain at Symmetric Point|
|193||Sep. 02(Fri) 4:00 PM||E6-2(1st fl) #1323||Dr. Yong-Joo Doh, Department of Physics and Photon Science, GIST||Quantum Electrical Transport in Topological Insulator Nanowires|
|192||Sep. 02(Fri) 2:30 PM||E6-2(1st fl.), #1323||Dr. Yong-Hyun Kim,Graduate School of Nanoscience and Technology, KAIST||Nanoscale Thermal Physics: Seebeck Effect and Nanoscale Friction|
|191||October 4 (Thu.), 16:00 PM||#1323, E6-2||Prof. Soo Jin Kim||Engineering light absorption in an ultrathin semiconductor metafilm|
|190||October 26 (Fri.), 4:00 PM||#1323, E6-2||Dr. Kyusung Hwang||Coexisting triple-point and nodal-line topological magnons and thermal Hall effect in pyrochlore iridates|
|189||October 25 (Thu.), 4:00 PM||#1323, E6-2||Dr. Gang Li||Abelian and non-Abelian dark photons|