|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|
|233||Apr. 08 (Fri.), 4:00 PM||E6-2. 5st fl. #1501||Dr. Changyoung Kim, SEOUL NATIONAL UNIV.||Spectroscopic studies of iron-based superconductors : what have we learned?|
|232||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|
|231||May. 3 (Fri), 11:00 AM||E6-2. 2st fl. #2502||Prof. Changhee Sohn||Exotic Magnetism|
|230||NOV. 23 (Fri), 03:00 PM||E6-2. 2st fl. #2501||Prof. Sang-Jin Sin||Entanglement string and Spin Liquid with Holographic duality|
|229||JAN. 7 (Mon), 03:00 PM||E6-2. 2st fl. #2501||Dr. Byoung min Kang||Many-Body Invariants for Multipoles in Higher-Order Topological Insulators|
|228||MAR. 26 (TUE), 0300 PM||E6-2. 2st fl. #2501||Prof. Jung Hoon Han||Consideration of thermal Hall effect in frustrated and un-frustrated quantum magnets|
|227||Jun. 18 (MON), 10:00 AM||E6-2. 2nd fl. #2502||Dr. Thibault VOGT||Rydberg electromagnetically induced transparency and microwave-to-optical conversion using Rydberg atoms|
|226||2015/10/16, 4PM||E6-2. 2nd fl. #2501||Prof. Yung-Fu Chen(Solid-state Laser Physics Laboratory,National Central University)||Fluctuations of entropy production in partially masked electric circuits|
|225||2015/09/14, 2PM||E6-2. 2nd fl. #2501||Dr. Hae Ja Lee ( Stanford University, SLAC )||Ultrafast X-ray Studies on Dynamics Matter in Extreme Conditions|
|224||Jan.9 (Wed.), 04:00 PM||E6-2. 2nd fl. #2501||Dr. Heung-Sik Kim||Molecular Mott state in the deficient spinel GaV4S8|
|223||2016/03/11 1:30 PM||E6-2. 1st fl. #1501||Dr. Kwon Park||Topological phases of matter in nonequilibrium: Topology of the Wannier-Stark ladder|
|222||2016/03/11 4 PM||E6-2. 1st fl. #1501||Dr. Tae-Hwan KIM (POSTECH)||Jan. Switching handedness of of chiral solitons in Z4 topological insulators|
|221||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|
|220||Apr. 01 (Fri.) 4:15 PM||E6-2. 1st fl. #1501||Dr. JONG SOO LIM, KIAS||Cotunneling drag effect in Coulomb-coupled quantum dots|
|219||Apr. 08 (Fri.), 13:30 PM||E6-2. 1st fl. #1501||Dr. Yunkyu Bang, Chonnam National Univ.||Theoretical Overview of Iron-based superconductors and its future|
|218||Oct. 12 (Fri.), 02:30 PM||E6-2. 1st fl. #1323||Dr. Daniel Kyungdeock Park||Quantum Advantage in Learning Parity with Noise|
|217||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|
|216||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|
|215||Apr. 12 (Tue.), 4 PM||E6-2. 1st fl. #1323||Dr. Jeehoon Kim, POSTECH||Confinement of Superconducting Vortices in Magnetic Force Microscopy|
|»||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”|