|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
|134||10AM, 29th Mar. / 13:30 PM, 30th Mar.||E6 #1501/zoom, E6 #2502/zoom||Dr. RYO HANAI (APCTP)||Non-reciprocal phase transitions|
|133||Nov. 9 (Fri.), 02:30 PM||E6-2. 1st fl. #1323||Dr. Pilkyung Moon||Moiré superlattices – from twisted bilayer graphene to quasicrystal|
|132||2015/10/16, 3PM||E6-2, 5th fl. #5318||Dr. Pierre Pugnat , (CNRS-LNCMI)||High Magnetic Fields to Probe the sub-eV range of Particle/Astroparticle Physics - From the OSQAR experiments at CERN up to new perspectives at LNCMI-Grenoble|
|131||July 2. 2018 (Monday) 3:00 PM||Seminar Room (C303), Creation Hall (3F), KAIST Munji Campus||Dr. Peter Winter (Argonne National Laboratory)||High Precision Magnetic Field Measurement for the Muon g-2 Experiment|
|130||Jun. 1(Wed) 10:30 AM||BK21 Conference Room (#1318, E6-2)||Dr. Noriaki Horiuchi, Editor, Nature Photonics||Welcome to Nature Photonics|
|129||May. 11 (Fri.), 04:00 PM||E6-2. 1st fl. #1323||Dr. Nam Kim||암페어 단위 재정의와 단전자 펌프 소자 개발|
|128||April 26 (Tue), 4PM||#1323(1st Floor. E6-2)||Dr. Myung-Ho Bae, Korea Research Institute of Standards and Science||Transport spectroscopy for electronic bands in carbon-based nanomaterials with weak-bond contacts|
|127||3 PM, 12 Jun (Wed), 2019||Rm# 1323, E6-2||Dr. Minyoung You||The relation between free and interacting fermionic SPT phases|
|126||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?|
|125||Apr. 28 (Fri.), 04:00 PM||#1323 (E6-2. 1st fl.)||Dr. Minkyung Jung Research Institute, DGIST||Carbon nanotubes coupled to superconducting impedance matching circuits|
|124||July 30 (Tue), 4:00 PM||#1323, E6-2||Dr. Mingu Kang||Dirac fermions and flat bands in correlated kagome metals|
|123||Nov. 3 (Fri.), 2:30 PM||#1323 (1st fl., E6-2.)||Dr. MinChul Lee(Department of Applied Physics, Kyung Hee Univ.)||Quantum Resistor-Capacitor Circuit with Majorana Edge States|
|122||Sep. 10 (Tue.), 03:00 PM||E6-2. 1st fl. #1323||Dr. Mikhail Kiselev||Two-Stage Kondo Effect|
|121||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|
|120||2015/11/23, 1:30PM||E6-2, #1323||Dr. Michael Park (Stanford University)||What's Beyond the Standard Model? Lessons from Run I and what might come in Run II|
|119||Jul. 08 (Fri.) 11:00 AM||#1323(E6-2. 1st fl.)||Dr. Michael Lawler(Binghampton Univ. / Cornell Univ.)||Isostatic magnetism|
|118||May 19, 2016 (Thur.) 3PM||May 19, 2016 (Thur.) 3PM,||Dr. Michael Betz, CERN||The CERN Resonant WISP Search: Development, Results and Lesson-Learned|
|117||2015/10/15, 10AM||E6-2, 5th fl. #5318||Dr. Mark D. Bird (Florida State University)||Development of Large-Bore, High Field Magnets at the NHMFL|
|116||Mar. 24 (Fri.), 2:30 PM||#1323 (1st fl. E6-2).||Dr. MahnSoo Choi||Topological Dynamics|
|115||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|