|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|
|119||Mar. 2nd (Thu), 4:00 p.m||#1323(E6-2. 1st fl.)||Dr. Jonathan Denlinger, Lawrence Berkeley National Lab||“Progress in the comparison of ARPES to DMFT for d and f strongly correlated electron systems”|
|118||Feb. 1 (Wed.), 2p.m.||#1323(E6-2. 1st fl.)||Dr. Michihisa Yamamoto, Department of Applied Physics, The University of Tokyo||Quantum electron optics using flying electrons|
|117||2017.1.9(Mon), 4PM||Lecture Hall, College of Natural Sciences [#1501,E6-2]||Prof. John Michael Kosterlitz, Brown University||Topological Defects and Phase Transitions"|
|116||Dec. 12th (Mon)||1:30p.m. #1323(E6-2. 1st fl.)||Dongjoon Song , AIST||“Possible symmetry in the phase diagrams of electron- & hole-doped cuprate high-Tc superconductors”|
|115||Dec. 9(Fri), 1:30 p.m.||#1323(E6-2. 1st fl.)||Dr. Jae Yoon Cho, POSTECH||Entanglement area law in strongly-correlated systems|
|114||Dec. 9(Fri), 4p.m.||#1323(E6-2. 1st fl.||Dr. Kun Woo Kim, KIAS||Shift Charge and Spin Photocurrents in Dirac Surface States of Topological Insulator|
|113||Dec. 8(Thu) 4p.m.||#1323(E6-2. 1st fl.)||Dr. Jinhyoung Lee, Hanyang University||Dynamical Resonance between Two Optical Cavities via Optomechanical Oscillator|
|112||Nov. 29(Tue) 4p.m.||#1323(E6-2. 1st fl.)||Dr. SungBin Lee, KAIST||Symmetry Protected Kondo Metals and Their Phase Transitions|
|111||Nov. 24(Thu) 4p.m.||#1323(E6-2. 1st fl.)||Dr. Jai-Min Choi, Chonbuk National Univiersity||Harmonic oscillator physics with single atoms in a state-selective optical potential|
|110||Nov. 18th (Fri) 10:30 a.m.||#5318(5th fl.)||Dr. 최 순 원, Havard University||Non-equilibrium many-body spin dynamics in diamond|
|109||Nov. 16 (Wed), 4p.m.||#1323(E6-2. 1st fl.)||Dr. Heung-Sik Kim , University of Toronto||Realizing Haldane Model in Fe-based Honeycomb Ferromagnetic Insulators|
|108||Nov. 10th(Thu) 4 p.m.||E6-2. #1323(1st fl.)||Prof. Min Seok Jang, Electrical Engineering, KAIST||Low Dimensional Active Plasmonics and Electron Optics in Graphene|
|107||Nov. 11th (Fri), 4 p.m.||#1323(E6-2. 1st fl.)||Dr. Bohm-Jung Yang, SNU||Dirac fermions in condensed matters|
|106||Nov. 11th(Fri), 1:30 p.m.||#1323(E6-2. 1st fl.)||Dr. Keun Su Kim, POSTECH||Bandgap Engineering of Black Phosphorus|
|105||Nov. 04 (Fri), 3:00 PM||E6-2. #1323(1st fl.)||Dr. Dohun Kim, Department of Physics and Astronomy, SNU||Quantum information experiments using few electron spins in semiconductors|
|104||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|
|103||Nov. 1st (Tue), 10:30AM||#1323(E6-2 1st fl.)||Dr. Gadi Eisenstein, Technion||Time scale dependent dynamics in InAs/InP quantum dot gain media|
|102||Oct. 27th(Thu) 4PM||#1323(E6-2)||Dr. 이 강 희, KAIST, Mechnical Engineering||Terahertz Metal Optics|
|101||Nov. 1 (Tue.) 2:30 pm||Seminar Room #1323(E6-2)||Prof. Youngjoon Kwon, Yonsei Univ.||Search for dark sector particles in the B-factory experiments|
|100||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|