visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2020-09-24 09:00 
연사  
장소 Zoom Video 

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 연사 제목
공지 2025-02-24 16:00    2025년 봄학기 콜로키움 안내
공지 2025-02-27 16:00    2025년 봄 물리학과 특별세미나 (광학/응집물리 분야)
295 2021-03-25 16:00    Search for dark matter axion with Rydberg atoms file
294 2021-04-02 14:30    Quantum computing and entanglement generation using trapped ions and photons
293 2021-04-02 16:00    Van der Waals heterostructures for orbital gating-based phototransistors and electronic spectroscopy
292 2021-04-09 10:00    Integrated Lithium Niobate Photonics file
291 2021-04-19 19:00    Evidence of Electrical Switching in Antiferromagnets and Coherent Spin Pumping file
290 2021-05-14 14:30    Electrically tunable spin valve effect in vertical van-der-Waals magnetic tunnel junctions file
289 2021-05-14 16:00    Spatial and temporal separation of environmental dephasing sources from solid-state quantum emitters file
288 2021-05-17 17:00    Spin current generation and detection in uniaxial antiferromagnets file
287 2021-05-27 16:00    찾아가는 물리연구 현장(유럽 입자물리학연구소 소개) file
286 2021-06-08 10:00    Photonic crystal devices for sensing file
285 2021-06-11 14:30    Engineering sound waves and vibrations in multi-mode nanomechanical systems file
284 2021-06-11 16:00    Pseudogap in surface-doped black phosphorus file
283 2021-06-22 17:00    Spintronics meets Quantum Materials file
282 2021-07-29 14:00    Gravitationally Induced Dark Sector and Inflationary Dynamics file
281 2021-11-02 16:00    Metrology of Band Topology via Resonant Inelastic X-ray Scattering file
280 2021-12-03 14:30    Topological Spin Textures: Skyrmions and Beyond file
279 2021-12-03 16:00    Nonequilibrium Heat Transport in Elemental Metals Probed by an Ultrathin Magnetic Thermometer file
278 2022-01-11 15:00    Ultrafast optical studies on CDW collective modes of the Weyl-CDW (TaSe4)2I file
277 2022-01-12 11:00    Spectroscopic study of trapped ions towards probing dark matter and new physics file
276 2022-01-17 14:00    Five Lectures on Observational Probes of Dark Energy file