visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
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

 

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 일시 장소 연사 제목
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
298 Feb. 25 - Jun 3  Rm. 1501 (E6)    Spring 2019: Physics Colloquium file
297 RM. 1323, E6-2    Spring 2019: Physics Seminar Serises file
296 August 27 (Tue.), 4:00PM  Rm. 1323, E6  Hiroshi Eisaki  Critical current properties of Fe-based superconductors file
295 August. 14th (Wed.), 4:00PM,  Rm. 1323, E6  Prof. Nicolas Treps  Quantum Optics, at the heart of quantum metrology and quantum information file
294 2019. 7. 16(화)  Rm. 1323 (E6-2)  Prof. Sidney Nagel  2019 Physics Distinguished Lecture file
293 8/19 (Mon), 10:00~11:30, 8/22 (Thur), 10:00~11:30  Rm. 1322, E6-2  Nicolas Treps  Tutorials on Multimode Quantum Optics in the Continuous Variable Regime file
292 3 PM, 12 Jun (Wed), 2019  Rm# 1323, E6-2  Dr. Minyoung You  The relation between free and interacting fermionic SPT phases file
291 Apr. 2 (Fri.), 04:00 PM  Online(Zoom)  Dr. Heejun Yang (KAIST)  Van der Waals heterostructures for orbital gating-based phototransistors and electronic spectroscopy
290 Apr. 2 (Fri.), 02:30 PM  Online(Zoom)  Dr. Tae Hyun Kim (SNU)  Quantum computing and entanglement generation using trapped ions and photons
289 Nov.26(Thu), 04:00PM  Online(Zoom)  Myung-Ki Kim  2020 가을학기 광학분야 특별세미나(Light Engineering Beyond the Diffraction Limit)
288 Nov 17th 12:00 PM  Online(Zoom)  Prof. Qiang Lin (Univ. of Rochester, USA)  Quantum- & Nano-Photonics" 세미나 시리즈 file
287 Mar25(Thur), 04:00PM  Online Seminar (Zoom)  Prof. Atsushi Tokiyasu (Tohoku Univ.)  Search for dark matter axion with Rydberg atoms file
286 Jun. 11 (Fri.), 04:00 PM  Online seminar  Dr. Keun Su Kim(Yonsei University)  Pseudogap in surface-doped black phosphorus file
285 Jun. 11 (Fri.), 02:30 PM  Online seminar  Dr. Jin Woong Cha(KRISS)  Engineering sound waves and vibrations in multi-mode nanomechanical systems file
284 May. 14 (Fri.), 02:30 PM  Online seminar  Dr. Suyong Jung(KRISS)  Electrically tunable spin valve effect in vertical van-der-Waals magnetic tunnel junctions file
283 May. 14 (Fri.), 04:00 PM  Online seminar  Dr. Je-Hyung Kim(UNIST)  Spatial and temporal separation of environmental dephasing sources from solid-state quantum emitters file
282 Jan.28(Thu), 06:00PM  Online Seminar  Alexandre Zagoskin(Loughborough Univ.)  Quantum metamaterials: concept, theory, prototypes and possible applications file
281 Mar 2 (Tue.), 16:00  Online  Dr. Dmitry Svintsov  Sensitive terahertz detection with graphene-based transistors file
280 Feb.17(Wed)~19(Fri), 09:00~11:00AM  Online  Prof. Subir Sachdev (Harvard University)  석학 대중 강연 및 강의 시리즈 file
279 Dec.23(Wed), 10:00~16:00  Online  Prof. YongKeun Park (KAIST) and etc.  Online workshop for Quantitative Phase Imaging file