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
126 2022-11-18 14:30  E6-2. 1st fl. #1323 & Zoom  Kondo cloud condensation in a highly-doped semiconductor metal file
125 2022-11-18 16:00  E6-2. 1st fl. #1323 & Zoom  Qubits, new experimental tools for physics file
124 2016-11-18 10:30  #5318(5th fl.)  Non-equilibrium many-body spin dynamics in diamond
123 2016-11-1 10:30  #1323(E6-2 1st fl.)  Time scale dependent dynamics in InAs/InP quantum dot gain media
122 2023-11-01 16:00  E6-2, #2502  [High Energy Theory Seminar] Modular functions and 3D N=4 rank-zero superconformal field theories
121 2021-11-02 16:00  자연과학동(E6-2) #1323  Metrology of Band Topology via Resonant Inelastic X-ray Scattering file
120 2020-11-20 14:30  Online  Lumpy Cooper pairs in an iron-based superconductor
119 2020-11-20 16:00  Online  Coherent control of field gradient induced quantum dot spin qubits
118 2023-11-22 10:00  E6-2, #5301 & zoom  [High Energy Theory Seminar] Exact Quantum Algorithms to Recognize Quantum Phases of Matter
117 2018-11-22 15:00  E6 Room(#1323)  Experimental and Computational Study on Physical Properties based on Granular System file
116 2018-11-23 15:00  E6-2. 2st fl. #2501  Entanglement string and Spin Liquid with Holographic duality file
115 2023-11-23 16:00  E6-2(Natural Science B/D). 1st fl. #1323  Deciphering the Enigma of Quantum Materials by X-ray Scattering and Spectroscopy
114 2016-11-24 16:00  #1323(E6-2. 1st fl.)  Harmonic oscillator physics with single atoms in a state-selective optical potential
113 2022-11-24 16:00  E6-2 #1323 & Zoom  Probing fundamental physics by mapping the mm and sub-mm sky
112 2022-11-25 11:00  E6-2 #1323  [Update 세미나영상](응집물리 세미나) DMFT+ NRG: From models to real materials, from local to nonlocal correlations file
111 2017-11-28 16:00  #1323 (E6-2. 1st fl.)  Physics after the lab and the desk: Your work in PRL file
110 2016-11-29 16:00  #1323(E6-2. 1st fl.)  Symmetry Protected Kondo Metals and Their Phase Transitions
109 2023-11-29 10:00  Zoom  [High Energy Theory Seminar] Averaged null energy and the renormalization group
108 2017-11-03 14:30  #1323 (1st fl., E6-2.)  Quantum Resistor-Capacitor Circuit with Majorana Edge States file
107 2017-11-03 16:00  #1323 (1st fl., E6-2.)  Expedition to the Kitaev Quantum Spin Liquid: Hunting for Majorana fermions file