visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2020-09-24 09:00 
일시 Sep. 24(Thu), 09:00~, Sep. 24(Thu), 16:00 ~ 
장소 Zoom Video 
연사 Akash V. Dixit (University of Chicago), Dr. Boris Ivanov (Novosibirsk State Technical University) 

Speaker: Akash V. Dixit (University of Chicago)

 

Date: September 24, 2020 (Thursday)

 

Time: 9:00 AM

 

Venue: Zoom Video Conference System (Please click the link below)

 

https://kaist.zoom.us/j/6108068959?pwd=TXV2OGlWdVRtcGhmNXVTRWlla2pHQT09


Meeting ID: 610 806 8959
 

Passcode: 131015

 

Topic: Searching for Dark Matter with a Superconducting Qubit

Abstract:

The gravitational evidence for the existence of dark matter is extensive 1 , yet thus far, dark matter has evaded direct detection in terrestrial experiments. Detection mechanisms for low mass dark matter candidates such as the axion 2–5 or hidden photon 6,7 leverage potential interactions with electromagnetic fields, whereby the dark matter (of unknown mass) on rare occasion converts into a single photon 8,7. Current dark matter searches operating at microwave frequencies, use a resonant cavity to coherently accumulate the field sourced by the dark matter and use a quantum limited linear amplifier to read out the cavity signal 9–12. Here, we report the development of a novel microwave photon counting technique and use it to set a new exclusion limit on hidden photon dark matter. We constrain the kinetic mixing angle to  ≤ 1.82 × 10−15 in a narrow band around 6.011 GHz (24.86 µeV) with an integration time of 8.33 s. We operate a superconducting qubit to make repeated quantum non-demolition measurements of cavity photons and apply a hidden Markov model analysis to reduce the noise to 15.7 dB below the quantum limit, with performance limited by the residual population of the system. The techniques presented here will dramatically improve the sensitivity of future dark matter searches in the range of 3-30 GHz and are generally applicable to measurements that require high sensitivity to inherently low signal photon rates.

 
 

Seminar Invitation (September 24, 2020), 4 PM

 
Speaker: Dr. Boris Ivanov (Novosibirsk State Technical University)


Date: September 24, 2020 (Thursday)

Time: 4:00 PM

Venue: Webinar Video Conference System (Please click the link below)

https://webinar.kafe.or.kr

Seminar Name: Cryogenic Microwave Circuit Development at the NSTU

Password: None

 

Topic: Cryogenic Microwave Circuit Development at the NSTU

Abstract:

During the seminar I am going to show the last scientific results of 4 research performed in the Laboratory of Quantum and Cryogenic Electronics. I will concentrate the major part of the talk around cryogenic amplifiers design, development and characterization. Thus, the cryogenic low noise amplifier with the noise temperature of 6 K and gain value of more than 30 dB is shown for the frequency range from 6 to 12 GHz. Based on such microwave amplifiers the superconducting X-mon qubit structures were measured. The experiments with qubits were performed at continues microwave field and with short microwave pulses. The qubit energy spectrums were obtained and based on the AC-Stark experiment the low average photon number close to single photon mode in qubit-resonator structure was obtained. From the other side for the bolometer circuits readout and Josephson junctions measurements the low frequency cryogenic amplifiers were designed and characterized. The minimum voltage noise density corresponds to 150 pV/root(Hz) with the gain value of more than 60 dB for the presented amplifiers.

번호 날짜 장소 제목
222 2023-03-22 16:00  E6-2, #2502  (High Energy Theory Seminar) Boltzmann or Bogoliubov? A Case of Gravitational Particle Production
221 2023-11-22 16:00  E6-2, #2502  [High Energy Theory Seminar] Renormalization and the Hierarchy Problem
220 2023-10-04 16:00  E6-2, #2502  [High-Energy Theory Seminar] Moving towards quantum technologies: the case of quantum batteries
219 2023-05-03 16:00  E6-2, #2502  Probing microscopic origins of axions by the chiral magnetic effect
218 2023-09-26 16:00  E6-2, #2502  [High Energy Theory Seminar]A new step in interacting dark sector cosmologies
217 2023-06-14 16:00  E6-2, #2502  [High-Energy Theory Seminar]Vertex algebras and extended operators in 4d N=2 SCFTs
216 2023-06-16 13:00  E6-2, #2502  Quantum critical states under extreme conditions
215 2023-11-01 16:00  E6-2, #2502  [High Energy Theory Seminar] Modular functions and 3D N=4 rank-zero superconformal field theories
214 2023-08-29 16:00  E6-2, #2502  [High Energy Theory Seminar] Towards string loop corrections in Calabi-Yau orientifold compactifications.
213 2023-06-01 16:00  E6-2, #5301  Hall viscosity and topological phenomena
212 2023-11-22 10:00  E6-2, #5301 & zoom  [High Energy Theory Seminar] Exact Quantum Algorithms to Recognize Quantum Phases of Matter
211 2020-02-12 13:00  E6-2, #5318  From inflation to new weak-scale file
210 2015-11-06 16:30  E6-2, #5318  Topological Dirac line nodes in centrosymmetric semimetals
209 2015-10-23 15:00  E6-2, #5318  Development of a Rogowski Coil as a new beam position monitor
208 2015-07-16 16:00  E6-2, 1318  Next-generation ultrafast laser technology for nonlinear optics and strong-field physics
207 2015-07-16 16:00  E6-2, 1501  KAIST Physics Distinguished Lecture
206 2016-03-11 13:30  E6-2, 1501 외  Physics Seminar Serises : 2016 Spring file
205 2019-07-03 15:00  E6-2, 2501  Many-body quantum electrodynamis (QED) with atoms and photons: A new platform for quantum optics" file
204 2018-06-14 10:00  E6-2, 2nd fl. #2502  Phonons and polariton-like particles in trapped ions for quantum computation and quantum simulation file
203 2015-10-16 15:00  E6-2, 5th fl. #5318  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