|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|
|279||October 18 (Thu.), 16:00 PM||#1323, E6-2||Prof. Jongseok Lee||Applications of nonlinear optics for condensed matter researches|
|278||November 21 (Wed.), 15:00 PM||#1323, E6-2||Prof. Seongshik Oh||Engineering topological quantum physics at the atomic scale|
|277||May 9 (Wed.), 04:00 PM||#1323, E6-2||Prof. Jong-Soo Rhyee||Recent advances in thermoelectric bulk composites|
|276||October 15 (Mon.), 16:00 PM||#1323, E6-2||Dr. Yongjoo Baek||Universal properties of macroscopic current-carrying systems|
|275||November 14 (Thu.), 16:00 PM||#1323, E6-2||Prof. Ji-Hun Kang||Semi-classical model of polariton propagation|
|274||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|
|273||October 11 (Thu.), 16:00 PM||#1323, E6-2||Prof. Joung-Real Ahn||Dirac electrons in a graphene quasicrystal|
|272||December 18 (Tue.), 4:00 PM||#1323, E6-2||Prof. Shin-ichi Uchida||Road to Higher Tc Superconductivity|
|271||October 25 (Thu.), 4:00 PM||#1323, E6-2||Dr. Gang Li||Abelian and non-Abelian dark photons|
|270||November 7 (Thu.), 16:00 PM||#1323, E6-2||Prof. Je-Hyung Kim||Integrated quantum photonics with solid-state quantum emitters|
|269||September 20 (Thu.), 16:00||#1323, E6-2||Prof. Joo-Hiuk Son||Toward Cancer Treatment Using Terahertz Radiation: Demethylation of Cancer DNA|
|268||December 3 (Tue.), 4:00 PM||#1323, E6-2||Dr. Jong Mok Ok||Toward Quantum Materials with Correlated Oxides|
|267||June 22 (Fri.), 04:00 PM||#1323, E6-2||Dr. Daniel Sando||Tuning functional properties of BiFeO3 films using strain and growth chemistry|
|266||June 22 (Fri.), 04:00 PM||#1323, E6-2||Dr. Daniel Sando||Tuning functional properties of BiFeO3 films using strain and growth chemistry|
|265||June 27 (Wed.), 13:30 PM||#1323, E6-2||Dr. Jung Sik Park||Magnetic reversal of artificial spin ice|
|264||May 29 (Tue.), 04:00 PM||#1323, E6-2||Prof. Jae-Won Jang||Investigation on metal nanostructure/semiconductor junction and its applications|
|263||November 29 (Thu.), 16:00 PM||#1323, E6-2||Dr. Kee suk Hong||양자 칸델라 실현을 위한 단일 광자 발생장치 개발|
|262||November 8 (Thu.), 16:00 PM||#1323, E6-2||이종완 박사||Conformality lost|
|261||September 5 (Wed.), 16:00 PM||#1323, E6-2||Dr. Dirk Wulferding||Shining a light on fractional excitations|
|260||February 20 (Thu), 4:00 PM||#1323, E6-2||Seunghyun Khim||Unconventional superconductivity in the locally non-centrosymmetric heavy-fermion CeRh2As2|