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
307 2023-10-11 16:00  CAPP Seminar Room C303, Creation Hall, KAIST Munji Campus  [CAPP seminar] Particle Physics with Neutrinos file
306 2018-07-09 14:00  #1323, E6-2  The principles of collective learning file
305 2023-06-01 16:00  E6-2, #5301  Hall viscosity and topological phenomena
304 2021-03-25 16:00  Online Seminar (Zoom)  Search for dark matter axion with Rydberg atoms file
303 2016-08-04 14:30  KAIST Natural Science Building (E6-5), EDU 3.0 Room(1st fl.)  Relational Logic (with applications to Quantum Mechanics, String Theory, Cosmology, Neutrino Oscillations, Statistical Mechanics)
302 2022-03-25 11:00  E6-1 #1323  (응집물리 세미나) Hund's metallicity in ruthenate systems file
301 2019-08-22 16:00  #1323, E6-2  Physics and Applications in Nanoelectronics and Nonomechanics file
300 2020-12-09 10:00  Zoom  Searching for the QCD axion with the ARIADNE experiment file
299 2022-08-08 14:00  E6-2 #2502  Classical Shadow Tomography for Analog Quantum Simulators
298 2022-09-21 10:30  E6-1 #1501  [Update 세미나 영상] Distinguished Lecture 'The Magic of Moiré Quantum Matter' Prof. Pablo Jarillo-Herrero(Department of Physics, MIT) file
297 2019-08-19 10:00  Rm. 1322, E6-2  Tutorials on Multimode Quantum Optics in the Continuous Variable Regime file
296 2016-10-17 11:00  #1323,(E6-2, 1st fl.)  IMS and examples of the studies on optoelectronic materials
295 2020-11-26 16:00  Online(Zoom)  2020 가을학기 광학분야 특별세미나(Light Engineering Beyond the Diffraction Limit)
294 2024-01-24 15:00  E6-2 #1323  Determination of single molecule loading rate during mechanotransduction file
293 2020-12-11 14:30  online  Antisymmetric interlayer exchange coupling in magnetic multilayers
292 2023-01-09 16:00  E6-2 #1323  Non-Hermitian Hopf-bundle Matter. Moon Jip Park (IBS-PCS)
291 2023-08-23 16:00  E6-2, #1322  [High Energy Theory Seminar] A spacetime tensor network for AdS3/CFT2
290 2022-04-13 10:30  E6 #1323/zoom  Harnessing topology and correlations from singularities in 3d-kagome metals
289 2019-01-23 16:00  Rm. C303, Creation Hall (3F), Munji Campus  Ultrasensitive Microwave Bolometer: Opportunity for Axion Detectors file
288 2023-06-22 16:00  E6-2,1323  [High Energy Physics Seminar] The Branes Behind Generalized Symmetry Operators