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
447 2021-02-15 17:00  Zoom  Magnetic Cluster Octupole Domain evolutation in chiral antiferromagnets file
446 2012-04-02 16:00  E6, 1501  A new route to ferroelectricity in magnetic spinels: a case of Co2MnO4
445 2020-12-10 13:55  Zoom  Consistency of Boltzmann equation and light dark matter from inflaton decay
444 2016-09-05 16:00  Natual Scien Bldg.(E6)m #1501  Physics Colloquium : 2016 Fall file
443 2021-01-28 15:00  Zoom  Topological Transport of Deconfined Hedgehogs in Magnets file
442 2018-12-26 16:00  E6-1. 3rd fl. #3434  Informal Workshop on Topology and Correlation file
441 2021-06-22 17:00  Zoom webinar  Spintronics meets Quantum Materials file
440 2021-06-08 10:00  Zoom webinar  Photonic crystal devices for sensing file
439 2023-06-30 11:00  E6-6 #1501  The Dual Mode Quantum Computer file
438 2023-11-29 10:00  Zoom  [High Energy Theory Seminar] Averaged null energy and the renormalization group
437 2020-09-14 17:30  Zoom webinar  KAIST Global Forum for Spin and Beyond (Third Forum) file
436 2022-11-03 13:00  E6-2 #1323  [High-Energy Theory Seminar] Supersymmetric observables via Fermi-gas method
435 2019-07-08 14:00  E6, #1322  Ultrabroadband squeezed pulses and their relation to relativity file
434 2023-04-05 16:00  E6-2, #2502  [High Energy Theory Seminar]Anomalies of Discrete 1-Form Symmetries in QCD-like Theories
433 2024-03-27 16:00  E6-2, #2502  [High Energy Theory Seminar] The Callan Rubakov Effect
432 2023-02-20 17:00  KI building (E4), Lecture Room Red (B501)  (Optics Seminar) Neural Holography for Next generation Virtual and Augmented Reality Displays file
431 2024-03-20 16:00  E6-2 #2502  [High-Energy Theory Seminar] Black hole states at finite N
430 2024-01-03 11:00  E6-2, #1323  Interplay of Strong Correlations, Topology, and Disorder in 2D Quantum Matters
429 2023-09-13 16:00  E6-2, #2502  [High Energy Theory Seminar] Cosmic Birefringence from Dark Photon
428 2022-06-23 11:00  E6 Room(#1322)  JILA’s search for the electron’s Electric Dipole Moment (eEDM) to probe physics beyond the standard model file