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
371 2022-05-18 16:00  E6-2. #1323 & Zoom  Geometry, Algebra, and Quantum Field Theory
370 2022-05-16 16:00  E6, #1501  Design synthetic topological matter with atoms and lights
369 2022-05-13 16:00  자연과학동(E6-2) 1st fl. #1323  High-fidelity iToffoli gate for fixed-frequency superconducting qubits file
368 2022-05-13 14:30  Zoom webinar  Topological Superconducting Spintronics Towards Zero-Power Computing Technologies file
367 2022-05-12 16:00  E6-2. #1323 & Zoom  New frontiers of electroweak physics at the LHC
366 2022-05-11 16:00  E6-2. #1323 & Zoom  Gravity as a phenomenon in quantum dynamics
365 2022-05-10 16:00  E6 1323  (광학분야 특별세미나)Testing quantum thermodynamics using quantum optics
364 2022-05-09 16:00  E6, #1501  Searching for new electronic properties in correlated material flatland
363 2022-05-02 16:00  E6, #1501  What can we learn from the history of science and technology?(우리말강의)
362 2022-04-28 16:00  E6 1323  (광학분야 특별세미나)Adiabaticity and symmetry in optical waveguide design
361 2022-04-25 16:00  E6, #1501  Ultrafast electron beam, a tool to explore the nanoscopic world of materials(우리말강의)
360 2022-04-15 11:00  Online seminar  (응집물리 세미나) First-principles studies of polar oxides and their applications file
359 2022-04-14 16:00  E6 1323  (광학분야 특별세미나)Holographic tomography of dielectric tensors at optical frequency
358 2022-04-13 10:30  E6 #1323/zoom  Harnessing topology and correlations from singularities in 3d-kagome metals
357 2022-04-11 16:00  E6, #1501  Emergence of Statistical Mechanics in Quantum Systems
356 2022-04-08 11:00  E6-1 #1323  (응집물리 세미나) Flat-surface-assisted physical phenomena occurring in single crystal metal thin film file
355 2022-04-04- 16:00  E6, #1501  New paradigms in Quantum Field Theory
354 2022-04-01 16:00  Zoom webinar  High-field Electron Transport and Interaction Induced Phenomena in 2D Materials file
353 2022-03-31 16:00  online  (광학분야 특별세미나)Ultrafast time-resolved spectroscopy in topological materials
352 2022-03-31 10:00  E6 #1501/zoom  Weiss fields for Quantum Spin Dynamics file