visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2016-10-18 15:00 
일시 Oct. 18 (Tue.), 3PM 
장소 E6-2. 1st fl. #1323 
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

 

Abstract:

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[1]. 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[3]. 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[6]. 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.

 

[1] Kurizki et.al., PNAS 112, 3866-3873 (2015).
[2] LaHaye et.al., Nature 459, 960-964 (2009).
[3] Suh et.al., Science 344, 1262-1265 (2014).
[4] Wollman et.al., Science 349, 952-955 (2015).
[5] Lei et.al., PRL 117, 100801 (2016).
[6] Nation et.al., PRA 93, 022510 (2016).

 

Contact: SunYoung Choi, (sunyoungchoi@kaist.ac.kr)
Center for Quantum Coherence in Condensed Matter, KAIST

번호 날짜 장소 제목
346 2019-05-02 16:00  #1323, E6-2  Anomalous optical properties of halide perovskites file
345 2016-05-19 15:00  May 19, 2016 (Thur.) 3PM,  The CERN Resonant WISP Search: Development, Results and Lesson-Learned
344 2016-05-19 16:00  #1323(E6-2, 1st fl.)  Nonlinear/quantum optical effect in silicon nano-photonics
343 2023-05-17 16:30  Zoom  Detecting Hidden Photon Dark Matter via the Excitation of Qubits file
342 2016-05-16 16:00  #1323(E6-2, 1st Fl.)  Tuning microwave cavities with biased nonlinear dielectrics for axion searches
341 2023-05-15 16:00  CAPP Seminar Room C303, Creation Hall, KAIST Munji Campus  Role of dark Higgs boson in DM physics and cosmology file
340 2016-05-13 13:30  E6. #1501(1st fl.)  Aperiodic crystals in low dimensions
339 2016-05-13 16:00  E6. #1501(1st fl.)  Graphene analogue in (111)- BaBiO3 bilayer heterostructures for topological electronics
338 2016-05-11 16:00  E6-2. #1323(1st fl.)  The quest for novel high-temperature superconductors---Prospects and progress in iridates
337 2019-05-01 16:00  #1323, E6-2  Raman and x-ray scattering study on correlated electron systems: two case examples file
336 2023-05-17 14:00  E6 #1323  Optical Response in the multilayer thin films
335 2022-05-20 11:00  E6-1 #1323  (응집물리 세미나) Exploration of new polymorphs in van der Waals crystals
334 2024-03-07 16:00  Zoom  [CAPP seminars] Development of Superconducting Transition Edge Sensors at SRON file
333 2023-03-30 16:00  CAPP Seminar Room C303, Creation Hall, KAIST Munji Campus  Detecting axions with chiral magnetic effects file
332 2023-03-27 15:00  CAPP Seminar Room C303, Creation Hall, KAIST Munji Campus  A coherent mechanical oscillator pumped by a suspended quantum dot file
331 2022-03-18 11:00  Online seminar  (응집물리 세미나) Illuminating exotic states of matter: Raman spectroscopy as an experimental tool to characterize quantum spin liquids file
330 2021-03-25 16:00  Online Seminar (Zoom)  Search for dark matter axion with Rydberg atoms file
329 2023-03-30 16:00  E6-2 #1323  (광학분야 세미나)Scalable quantum entanglement in trapped-ions based quantum computer
328 2017-03-02 16:00  #1323(E6-2. 1st fl.)  “Progress in the comparison of ARPES to DMFT for d and f strongly correlated electron systems”
327 2019-03-29 16:00  E6-2. 1st fl. #1323  Coherent Quantum Control and Magnetism on atoms – Trapped ion and ESR STM file